1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB hub driver.
4  *
5  * (C) Copyright 1999 Linus Torvalds
6  * (C) Copyright 1999 Johannes Erdfelt
7  * (C) Copyright 1999 Gregory P. Smith
8  * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
9  *
10  * Released under the GPLv2 only.
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/module.h>
16 #include <linux/moduleparam.h>
17 #include <linux/completion.h>
18 #include <linux/sched/mm.h>
19 #include <linux/list.h>
20 #include <linux/slab.h>
21 #include <linux/kcov.h>
22 #include <linux/ioctl.h>
23 #include <linux/usb.h>
24 #include <linux/usbdevice_fs.h>
25 #include <linux/usb/hcd.h>
26 #include <linux/usb/onboard_hub.h>
27 #include <linux/usb/otg.h>
28 #include <linux/usb/quirks.h>
29 #include <linux/workqueue.h>
30 #include <linux/mutex.h>
31 #include <linux/random.h>
32 #include <linux/pm_qos.h>
33 #include <linux/kobject.h>
34 
35 #include <linux/bitfield.h>
36 #include <linux/uaccess.h>
37 #include <asm/byteorder.h>
38 
39 #include "hub.h"
40 #include "otg_productlist.h"
41 
42 #define USB_VENDOR_GENESYS_LOGIC		0x05e3
43 #define USB_VENDOR_SMSC				0x0424
44 #define USB_PRODUCT_USB5534B			0x5534
45 #define USB_VENDOR_CYPRESS			0x04b4
46 #define USB_PRODUCT_CY7C65632			0x6570
47 #define USB_VENDOR_TEXAS_INSTRUMENTS		0x0451
48 #define USB_PRODUCT_TUSB8041_USB3		0x8140
49 #define USB_PRODUCT_TUSB8041_USB2		0x8142
50 #define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND	0x01
51 #define HUB_QUIRK_DISABLE_AUTOSUSPEND		0x02
52 
53 #define USB_TP_TRANSMISSION_DELAY	40	/* ns */
54 #define USB_TP_TRANSMISSION_DELAY_MAX	65535	/* ns */
55 #define USB_PING_RESPONSE_TIME		400	/* ns */
56 
57 /* Protect struct usb_device->state and ->children members
58  * Note: Both are also protected by ->dev.sem, except that ->state can
59  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
60 static DEFINE_SPINLOCK(device_state_lock);
61 
62 /* workqueue to process hub events */
63 static struct workqueue_struct *hub_wq;
64 static void hub_event(struct work_struct *work);
65 
66 /* synchronize hub-port add/remove and peering operations */
67 DEFINE_MUTEX(usb_port_peer_mutex);
68 
69 /* cycle leds on hubs that aren't blinking for attention */
70 static bool blinkenlights;
71 module_param(blinkenlights, bool, S_IRUGO);
72 MODULE_PARM_DESC(blinkenlights, "true to cycle leds on hubs");
73 
74 /*
75  * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
76  * 10 seconds to send reply for the initial 64-byte descriptor request.
77  */
78 /* define initial 64-byte descriptor request timeout in milliseconds */
79 static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
80 module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
81 MODULE_PARM_DESC(initial_descriptor_timeout,
82 		"initial 64-byte descriptor request timeout in milliseconds "
83 		"(default 5000 - 5.0 seconds)");
84 
85 /*
86  * As of 2.6.10 we introduce a new USB device initialization scheme which
87  * closely resembles the way Windows works.  Hopefully it will be compatible
88  * with a wider range of devices than the old scheme.  However some previously
89  * working devices may start giving rise to "device not accepting address"
90  * errors; if that happens the user can try the old scheme by adjusting the
91  * following module parameters.
92  *
93  * For maximum flexibility there are two boolean parameters to control the
94  * hub driver's behavior.  On the first initialization attempt, if the
95  * "old_scheme_first" parameter is set then the old scheme will be used,
96  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
97  * is set, then the driver will make another attempt, using the other scheme.
98  */
99 static bool old_scheme_first;
100 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
101 MODULE_PARM_DESC(old_scheme_first,
102 		 "start with the old device initialization scheme");
103 
104 static bool use_both_schemes = true;
105 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
106 MODULE_PARM_DESC(use_both_schemes,
107 		"try the other device initialization scheme if the "
108 		"first one fails");
109 
110 /* Mutual exclusion for EHCI CF initialization.  This interferes with
111  * port reset on some companion controllers.
112  */
113 DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
114 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
115 
116 #define HUB_DEBOUNCE_TIMEOUT	2000
117 #define HUB_DEBOUNCE_STEP	  25
118 #define HUB_DEBOUNCE_STABLE	 100
119 
120 static void hub_release(struct kref *kref);
121 static int usb_reset_and_verify_device(struct usb_device *udev);
122 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state);
123 static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1,
124 		u16 portstatus);
125 
portspeed(struct usb_hub * hub,int portstatus)126 static inline char *portspeed(struct usb_hub *hub, int portstatus)
127 {
128 	if (hub_is_superspeedplus(hub->hdev))
129 		return "10.0 Gb/s";
130 	if (hub_is_superspeed(hub->hdev))
131 		return "5.0 Gb/s";
132 	if (portstatus & USB_PORT_STAT_HIGH_SPEED)
133 		return "480 Mb/s";
134 	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
135 		return "1.5 Mb/s";
136 	else
137 		return "12 Mb/s";
138 }
139 
140 /* Note that hdev or one of its children must be locked! */
usb_hub_to_struct_hub(struct usb_device * hdev)141 struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev)
142 {
143 	if (!hdev || !hdev->actconfig || !hdev->maxchild)
144 		return NULL;
145 	return usb_get_intfdata(hdev->actconfig->interface[0]);
146 }
147 
usb_device_supports_lpm(struct usb_device * udev)148 int usb_device_supports_lpm(struct usb_device *udev)
149 {
150 	/* Some devices have trouble with LPM */
151 	if (udev->quirks & USB_QUIRK_NO_LPM)
152 		return 0;
153 
154 	/* Skip if the device BOS descriptor couldn't be read */
155 	if (!udev->bos)
156 		return 0;
157 
158 	/* USB 2.1 (and greater) devices indicate LPM support through
159 	 * their USB 2.0 Extended Capabilities BOS descriptor.
160 	 */
161 	if (udev->speed == USB_SPEED_HIGH || udev->speed == USB_SPEED_FULL) {
162 		if (udev->bos->ext_cap &&
163 			(USB_LPM_SUPPORT &
164 			 le32_to_cpu(udev->bos->ext_cap->bmAttributes)))
165 			return 1;
166 		return 0;
167 	}
168 
169 	/*
170 	 * According to the USB 3.0 spec, all USB 3.0 devices must support LPM.
171 	 * However, there are some that don't, and they set the U1/U2 exit
172 	 * latencies to zero.
173 	 */
174 	if (!udev->bos->ss_cap) {
175 		dev_info(&udev->dev, "No LPM exit latency info found, disabling LPM.\n");
176 		return 0;
177 	}
178 
179 	if (udev->bos->ss_cap->bU1devExitLat == 0 &&
180 			udev->bos->ss_cap->bU2DevExitLat == 0) {
181 		if (udev->parent)
182 			dev_info(&udev->dev, "LPM exit latency is zeroed, disabling LPM.\n");
183 		else
184 			dev_info(&udev->dev, "We don't know the algorithms for LPM for this host, disabling LPM.\n");
185 		return 0;
186 	}
187 
188 	if (!udev->parent || udev->parent->lpm_capable)
189 		return 1;
190 	return 0;
191 }
192 
193 /*
194  * Set the Maximum Exit Latency (MEL) for the host to wakup up the path from
195  * U1/U2, send a PING to the device and receive a PING_RESPONSE.
196  * See USB 3.1 section C.1.5.2
197  */
usb_set_lpm_mel(struct usb_device * udev,struct usb3_lpm_parameters * udev_lpm_params,unsigned int udev_exit_latency,struct usb_hub * hub,struct usb3_lpm_parameters * hub_lpm_params,unsigned int hub_exit_latency)198 static void usb_set_lpm_mel(struct usb_device *udev,
199 		struct usb3_lpm_parameters *udev_lpm_params,
200 		unsigned int udev_exit_latency,
201 		struct usb_hub *hub,
202 		struct usb3_lpm_parameters *hub_lpm_params,
203 		unsigned int hub_exit_latency)
204 {
205 	unsigned int total_mel;
206 
207 	/*
208 	 * tMEL1. time to transition path from host to device into U0.
209 	 * MEL for parent already contains the delay up to parent, so only add
210 	 * the exit latency for the last link (pick the slower exit latency),
211 	 * and the hub header decode latency. See USB 3.1 section C 2.2.1
212 	 * Store MEL in nanoseconds
213 	 */
214 	total_mel = hub_lpm_params->mel +
215 		max(udev_exit_latency, hub_exit_latency) * 1000 +
216 		hub->descriptor->u.ss.bHubHdrDecLat * 100;
217 
218 	/*
219 	 * tMEL2. Time to submit PING packet. Sum of tTPTransmissionDelay for
220 	 * each link + wHubDelay for each hub. Add only for last link.
221 	 * tMEL4, the time for PING_RESPONSE to traverse upstream is similar.
222 	 * Multiply by 2 to include it as well.
223 	 */
224 	total_mel += (__le16_to_cpu(hub->descriptor->u.ss.wHubDelay) +
225 		      USB_TP_TRANSMISSION_DELAY) * 2;
226 
227 	/*
228 	 * tMEL3, tPingResponse. Time taken by device to generate PING_RESPONSE
229 	 * after receiving PING. Also add 2100ns as stated in USB 3.1 C 1.5.2.4
230 	 * to cover the delay if the PING_RESPONSE is queued behind a Max Packet
231 	 * Size DP.
232 	 * Note these delays should be added only once for the entire path, so
233 	 * add them to the MEL of the device connected to the roothub.
234 	 */
235 	if (!hub->hdev->parent)
236 		total_mel += USB_PING_RESPONSE_TIME + 2100;
237 
238 	udev_lpm_params->mel = total_mel;
239 }
240 
241 /*
242  * Set the maximum Device to Host Exit Latency (PEL) for the device to initiate
243  * a transition from either U1 or U2.
244  */
usb_set_lpm_pel(struct usb_device * udev,struct usb3_lpm_parameters * udev_lpm_params,unsigned int udev_exit_latency,struct usb_hub * hub,struct usb3_lpm_parameters * hub_lpm_params,unsigned int hub_exit_latency,unsigned int port_to_port_exit_latency)245 static void usb_set_lpm_pel(struct usb_device *udev,
246 		struct usb3_lpm_parameters *udev_lpm_params,
247 		unsigned int udev_exit_latency,
248 		struct usb_hub *hub,
249 		struct usb3_lpm_parameters *hub_lpm_params,
250 		unsigned int hub_exit_latency,
251 		unsigned int port_to_port_exit_latency)
252 {
253 	unsigned int first_link_pel;
254 	unsigned int hub_pel;
255 
256 	/*
257 	 * First, the device sends an LFPS to transition the link between the
258 	 * device and the parent hub into U0.  The exit latency is the bigger of
259 	 * the device exit latency or the hub exit latency.
260 	 */
261 	if (udev_exit_latency > hub_exit_latency)
262 		first_link_pel = udev_exit_latency * 1000;
263 	else
264 		first_link_pel = hub_exit_latency * 1000;
265 
266 	/*
267 	 * When the hub starts to receive the LFPS, there is a slight delay for
268 	 * it to figure out that one of the ports is sending an LFPS.  Then it
269 	 * will forward the LFPS to its upstream link.  The exit latency is the
270 	 * delay, plus the PEL that we calculated for this hub.
271 	 */
272 	hub_pel = port_to_port_exit_latency * 1000 + hub_lpm_params->pel;
273 
274 	/*
275 	 * According to figure C-7 in the USB 3.0 spec, the PEL for this device
276 	 * is the greater of the two exit latencies.
277 	 */
278 	if (first_link_pel > hub_pel)
279 		udev_lpm_params->pel = first_link_pel;
280 	else
281 		udev_lpm_params->pel = hub_pel;
282 }
283 
284 /*
285  * Set the System Exit Latency (SEL) to indicate the total worst-case time from
286  * when a device initiates a transition to U0, until when it will receive the
287  * first packet from the host controller.
288  *
289  * Section C.1.5.1 describes the four components to this:
290  *  - t1: device PEL
291  *  - t2: time for the ERDY to make it from the device to the host.
292  *  - t3: a host-specific delay to process the ERDY.
293  *  - t4: time for the packet to make it from the host to the device.
294  *
295  * t3 is specific to both the xHCI host and the platform the host is integrated
296  * into.  The Intel HW folks have said it's negligible, FIXME if a different
297  * vendor says otherwise.
298  */
usb_set_lpm_sel(struct usb_device * udev,struct usb3_lpm_parameters * udev_lpm_params)299 static void usb_set_lpm_sel(struct usb_device *udev,
300 		struct usb3_lpm_parameters *udev_lpm_params)
301 {
302 	struct usb_device *parent;
303 	unsigned int num_hubs;
304 	unsigned int total_sel;
305 
306 	/* t1 = device PEL */
307 	total_sel = udev_lpm_params->pel;
308 	/* How many external hubs are in between the device & the root port. */
309 	for (parent = udev->parent, num_hubs = 0; parent->parent;
310 			parent = parent->parent)
311 		num_hubs++;
312 	/* t2 = 2.1us + 250ns * (num_hubs - 1) */
313 	if (num_hubs > 0)
314 		total_sel += 2100 + 250 * (num_hubs - 1);
315 
316 	/* t4 = 250ns * num_hubs */
317 	total_sel += 250 * num_hubs;
318 
319 	udev_lpm_params->sel = total_sel;
320 }
321 
usb_set_lpm_parameters(struct usb_device * udev)322 static void usb_set_lpm_parameters(struct usb_device *udev)
323 {
324 	struct usb_hub *hub;
325 	unsigned int port_to_port_delay;
326 	unsigned int udev_u1_del;
327 	unsigned int udev_u2_del;
328 	unsigned int hub_u1_del;
329 	unsigned int hub_u2_del;
330 
331 	if (!udev->lpm_capable || udev->speed < USB_SPEED_SUPER)
332 		return;
333 
334 	/* Skip if the device BOS descriptor couldn't be read */
335 	if (!udev->bos)
336 		return;
337 
338 	hub = usb_hub_to_struct_hub(udev->parent);
339 	/* It doesn't take time to transition the roothub into U0, since it
340 	 * doesn't have an upstream link.
341 	 */
342 	if (!hub)
343 		return;
344 
345 	udev_u1_del = udev->bos->ss_cap->bU1devExitLat;
346 	udev_u2_del = le16_to_cpu(udev->bos->ss_cap->bU2DevExitLat);
347 	hub_u1_del = udev->parent->bos->ss_cap->bU1devExitLat;
348 	hub_u2_del = le16_to_cpu(udev->parent->bos->ss_cap->bU2DevExitLat);
349 
350 	usb_set_lpm_mel(udev, &udev->u1_params, udev_u1_del,
351 			hub, &udev->parent->u1_params, hub_u1_del);
352 
353 	usb_set_lpm_mel(udev, &udev->u2_params, udev_u2_del,
354 			hub, &udev->parent->u2_params, hub_u2_del);
355 
356 	/*
357 	 * Appendix C, section C.2.2.2, says that there is a slight delay from
358 	 * when the parent hub notices the downstream port is trying to
359 	 * transition to U0 to when the hub initiates a U0 transition on its
360 	 * upstream port.  The section says the delays are tPort2PortU1EL and
361 	 * tPort2PortU2EL, but it doesn't define what they are.
362 	 *
363 	 * The hub chapter, sections 10.4.2.4 and 10.4.2.5 seem to be talking
364 	 * about the same delays.  Use the maximum delay calculations from those
365 	 * sections.  For U1, it's tHubPort2PortExitLat, which is 1us max.  For
366 	 * U2, it's tHubPort2PortExitLat + U2DevExitLat - U1DevExitLat.  I
367 	 * assume the device exit latencies they are talking about are the hub
368 	 * exit latencies.
369 	 *
370 	 * What do we do if the U2 exit latency is less than the U1 exit
371 	 * latency?  It's possible, although not likely...
372 	 */
373 	port_to_port_delay = 1;
374 
375 	usb_set_lpm_pel(udev, &udev->u1_params, udev_u1_del,
376 			hub, &udev->parent->u1_params, hub_u1_del,
377 			port_to_port_delay);
378 
379 	if (hub_u2_del > hub_u1_del)
380 		port_to_port_delay = 1 + hub_u2_del - hub_u1_del;
381 	else
382 		port_to_port_delay = 1 + hub_u1_del;
383 
384 	usb_set_lpm_pel(udev, &udev->u2_params, udev_u2_del,
385 			hub, &udev->parent->u2_params, hub_u2_del,
386 			port_to_port_delay);
387 
388 	/* Now that we've got PEL, calculate SEL. */
389 	usb_set_lpm_sel(udev, &udev->u1_params);
390 	usb_set_lpm_sel(udev, &udev->u2_params);
391 }
392 
393 /* USB 2.0 spec Section 11.24.4.5 */
get_hub_descriptor(struct usb_device * hdev,struct usb_hub_descriptor * desc)394 static int get_hub_descriptor(struct usb_device *hdev,
395 		struct usb_hub_descriptor *desc)
396 {
397 	int i, ret, size;
398 	unsigned dtype;
399 
400 	if (hub_is_superspeed(hdev)) {
401 		dtype = USB_DT_SS_HUB;
402 		size = USB_DT_SS_HUB_SIZE;
403 	} else {
404 		dtype = USB_DT_HUB;
405 		size = sizeof(struct usb_hub_descriptor);
406 	}
407 
408 	for (i = 0; i < 3; i++) {
409 		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
410 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
411 			dtype << 8, 0, desc, size,
412 			USB_CTRL_GET_TIMEOUT);
413 		if (hub_is_superspeed(hdev)) {
414 			if (ret == size)
415 				return ret;
416 		} else if (ret >= USB_DT_HUB_NONVAR_SIZE + 2) {
417 			/* Make sure we have the DeviceRemovable field. */
418 			size = USB_DT_HUB_NONVAR_SIZE + desc->bNbrPorts / 8 + 1;
419 			if (ret < size)
420 				return -EMSGSIZE;
421 			return ret;
422 		}
423 	}
424 	return -EINVAL;
425 }
426 
427 /*
428  * USB 2.0 spec Section 11.24.2.1
429  */
clear_hub_feature(struct usb_device * hdev,int feature)430 static int clear_hub_feature(struct usb_device *hdev, int feature)
431 {
432 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
433 		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
434 }
435 
436 /*
437  * USB 2.0 spec Section 11.24.2.2
438  */
usb_clear_port_feature(struct usb_device * hdev,int port1,int feature)439 int usb_clear_port_feature(struct usb_device *hdev, int port1, int feature)
440 {
441 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
442 		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
443 		NULL, 0, 1000);
444 }
445 
446 /*
447  * USB 2.0 spec Section 11.24.2.13
448  */
set_port_feature(struct usb_device * hdev,int port1,int feature)449 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
450 {
451 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
452 		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
453 		NULL, 0, 1000);
454 }
455 
to_led_name(int selector)456 static char *to_led_name(int selector)
457 {
458 	switch (selector) {
459 	case HUB_LED_AMBER:
460 		return "amber";
461 	case HUB_LED_GREEN:
462 		return "green";
463 	case HUB_LED_OFF:
464 		return "off";
465 	case HUB_LED_AUTO:
466 		return "auto";
467 	default:
468 		return "??";
469 	}
470 }
471 
472 /*
473  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
474  * for info about using port indicators
475  */
set_port_led(struct usb_hub * hub,int port1,int selector)476 static void set_port_led(struct usb_hub *hub, int port1, int selector)
477 {
478 	struct usb_port *port_dev = hub->ports[port1 - 1];
479 	int status;
480 
481 	status = set_port_feature(hub->hdev, (selector << 8) | port1,
482 			USB_PORT_FEAT_INDICATOR);
483 	dev_dbg(&port_dev->dev, "indicator %s status %d\n",
484 		to_led_name(selector), status);
485 }
486 
487 #define	LED_CYCLE_PERIOD	((2*HZ)/3)
488 
led_work(struct work_struct * work)489 static void led_work(struct work_struct *work)
490 {
491 	struct usb_hub		*hub =
492 		container_of(work, struct usb_hub, leds.work);
493 	struct usb_device	*hdev = hub->hdev;
494 	unsigned		i;
495 	unsigned		changed = 0;
496 	int			cursor = -1;
497 
498 	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
499 		return;
500 
501 	for (i = 0; i < hdev->maxchild; i++) {
502 		unsigned	selector, mode;
503 
504 		/* 30%-50% duty cycle */
505 
506 		switch (hub->indicator[i]) {
507 		/* cycle marker */
508 		case INDICATOR_CYCLE:
509 			cursor = i;
510 			selector = HUB_LED_AUTO;
511 			mode = INDICATOR_AUTO;
512 			break;
513 		/* blinking green = sw attention */
514 		case INDICATOR_GREEN_BLINK:
515 			selector = HUB_LED_GREEN;
516 			mode = INDICATOR_GREEN_BLINK_OFF;
517 			break;
518 		case INDICATOR_GREEN_BLINK_OFF:
519 			selector = HUB_LED_OFF;
520 			mode = INDICATOR_GREEN_BLINK;
521 			break;
522 		/* blinking amber = hw attention */
523 		case INDICATOR_AMBER_BLINK:
524 			selector = HUB_LED_AMBER;
525 			mode = INDICATOR_AMBER_BLINK_OFF;
526 			break;
527 		case INDICATOR_AMBER_BLINK_OFF:
528 			selector = HUB_LED_OFF;
529 			mode = INDICATOR_AMBER_BLINK;
530 			break;
531 		/* blink green/amber = reserved */
532 		case INDICATOR_ALT_BLINK:
533 			selector = HUB_LED_GREEN;
534 			mode = INDICATOR_ALT_BLINK_OFF;
535 			break;
536 		case INDICATOR_ALT_BLINK_OFF:
537 			selector = HUB_LED_AMBER;
538 			mode = INDICATOR_ALT_BLINK;
539 			break;
540 		default:
541 			continue;
542 		}
543 		if (selector != HUB_LED_AUTO)
544 			changed = 1;
545 		set_port_led(hub, i + 1, selector);
546 		hub->indicator[i] = mode;
547 	}
548 	if (!changed && blinkenlights) {
549 		cursor++;
550 		cursor %= hdev->maxchild;
551 		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
552 		hub->indicator[cursor] = INDICATOR_CYCLE;
553 		changed++;
554 	}
555 	if (changed)
556 		queue_delayed_work(system_power_efficient_wq,
557 				&hub->leds, LED_CYCLE_PERIOD);
558 }
559 
560 /* use a short timeout for hub/port status fetches */
561 #define	USB_STS_TIMEOUT		1000
562 #define	USB_STS_RETRIES		5
563 
564 /*
565  * USB 2.0 spec Section 11.24.2.6
566  */
get_hub_status(struct usb_device * hdev,struct usb_hub_status * data)567 static int get_hub_status(struct usb_device *hdev,
568 		struct usb_hub_status *data)
569 {
570 	int i, status = -ETIMEDOUT;
571 
572 	for (i = 0; i < USB_STS_RETRIES &&
573 			(status == -ETIMEDOUT || status == -EPIPE); i++) {
574 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
575 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
576 			data, sizeof(*data), USB_STS_TIMEOUT);
577 	}
578 	return status;
579 }
580 
581 /*
582  * USB 2.0 spec Section 11.24.2.7
583  * USB 3.1 takes into use the wValue and wLength fields, spec Section 10.16.2.6
584  */
get_port_status(struct usb_device * hdev,int port1,void * data,u16 value,u16 length)585 static int get_port_status(struct usb_device *hdev, int port1,
586 			   void *data, u16 value, u16 length)
587 {
588 	int i, status = -ETIMEDOUT;
589 
590 	for (i = 0; i < USB_STS_RETRIES &&
591 			(status == -ETIMEDOUT || status == -EPIPE); i++) {
592 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
593 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, value,
594 			port1, data, length, USB_STS_TIMEOUT);
595 	}
596 	return status;
597 }
598 
hub_ext_port_status(struct usb_hub * hub,int port1,int type,u16 * status,u16 * change,u32 * ext_status)599 static int hub_ext_port_status(struct usb_hub *hub, int port1, int type,
600 			       u16 *status, u16 *change, u32 *ext_status)
601 {
602 	int ret;
603 	int len = 4;
604 
605 	if (type != HUB_PORT_STATUS)
606 		len = 8;
607 
608 	mutex_lock(&hub->status_mutex);
609 	ret = get_port_status(hub->hdev, port1, &hub->status->port, type, len);
610 	if (ret < len) {
611 		if (ret != -ENODEV)
612 			dev_err(hub->intfdev,
613 				"%s failed (err = %d)\n", __func__, ret);
614 		if (ret >= 0)
615 			ret = -EIO;
616 	} else {
617 		*status = le16_to_cpu(hub->status->port.wPortStatus);
618 		*change = le16_to_cpu(hub->status->port.wPortChange);
619 		if (type != HUB_PORT_STATUS && ext_status)
620 			*ext_status = le32_to_cpu(
621 				hub->status->port.dwExtPortStatus);
622 		ret = 0;
623 	}
624 	mutex_unlock(&hub->status_mutex);
625 
626 	/*
627 	 * There is no need to lock status_mutex here, because status_mutex
628 	 * protects hub->status, and the phy driver only checks the port
629 	 * status without changing the status.
630 	 */
631 	if (!ret) {
632 		struct usb_device *hdev = hub->hdev;
633 
634 		/*
635 		 * Only roothub will be notified of port state changes,
636 		 * since the USB PHY only cares about changes at the next
637 		 * level.
638 		 */
639 		if (is_root_hub(hdev)) {
640 			struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
641 
642 			if (hcd->usb_phy)
643 				usb_phy_notify_port_status(hcd->usb_phy,
644 							   port1 - 1, *status, *change);
645 		}
646 	}
647 
648 	return ret;
649 }
650 
usb_hub_port_status(struct usb_hub * hub,int port1,u16 * status,u16 * change)651 int usb_hub_port_status(struct usb_hub *hub, int port1,
652 		u16 *status, u16 *change)
653 {
654 	return hub_ext_port_status(hub, port1, HUB_PORT_STATUS,
655 				   status, change, NULL);
656 }
657 
hub_resubmit_irq_urb(struct usb_hub * hub)658 static void hub_resubmit_irq_urb(struct usb_hub *hub)
659 {
660 	unsigned long flags;
661 	int status;
662 
663 	spin_lock_irqsave(&hub->irq_urb_lock, flags);
664 
665 	if (hub->quiescing) {
666 		spin_unlock_irqrestore(&hub->irq_urb_lock, flags);
667 		return;
668 	}
669 
670 	status = usb_submit_urb(hub->urb, GFP_ATOMIC);
671 	if (status && status != -ENODEV && status != -EPERM &&
672 	    status != -ESHUTDOWN) {
673 		dev_err(hub->intfdev, "resubmit --> %d\n", status);
674 		mod_timer(&hub->irq_urb_retry, jiffies + HZ);
675 	}
676 
677 	spin_unlock_irqrestore(&hub->irq_urb_lock, flags);
678 }
679 
hub_retry_irq_urb(struct timer_list * t)680 static void hub_retry_irq_urb(struct timer_list *t)
681 {
682 	struct usb_hub *hub = from_timer(hub, t, irq_urb_retry);
683 
684 	hub_resubmit_irq_urb(hub);
685 }
686 
687 
kick_hub_wq(struct usb_hub * hub)688 static void kick_hub_wq(struct usb_hub *hub)
689 {
690 	struct usb_interface *intf;
691 
692 	if (hub->disconnected || work_pending(&hub->events))
693 		return;
694 
695 	/*
696 	 * Suppress autosuspend until the event is proceed.
697 	 *
698 	 * Be careful and make sure that the symmetric operation is
699 	 * always called. We are here only when there is no pending
700 	 * work for this hub. Therefore put the interface either when
701 	 * the new work is called or when it is canceled.
702 	 */
703 	intf = to_usb_interface(hub->intfdev);
704 	usb_autopm_get_interface_no_resume(intf);
705 	kref_get(&hub->kref);
706 
707 	if (queue_work(hub_wq, &hub->events))
708 		return;
709 
710 	/* the work has already been scheduled */
711 	usb_autopm_put_interface_async(intf);
712 	kref_put(&hub->kref, hub_release);
713 }
714 
usb_kick_hub_wq(struct usb_device * hdev)715 void usb_kick_hub_wq(struct usb_device *hdev)
716 {
717 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
718 
719 	if (hub)
720 		kick_hub_wq(hub);
721 }
722 
723 /*
724  * Let the USB core know that a USB 3.0 device has sent a Function Wake Device
725  * Notification, which indicates it had initiated remote wakeup.
726  *
727  * USB 3.0 hubs do not report the port link state change from U3 to U0 when the
728  * device initiates resume, so the USB core will not receive notice of the
729  * resume through the normal hub interrupt URB.
730  */
usb_wakeup_notification(struct usb_device * hdev,unsigned int portnum)731 void usb_wakeup_notification(struct usb_device *hdev,
732 		unsigned int portnum)
733 {
734 	struct usb_hub *hub;
735 	struct usb_port *port_dev;
736 
737 	if (!hdev)
738 		return;
739 
740 	hub = usb_hub_to_struct_hub(hdev);
741 	if (hub) {
742 		port_dev = hub->ports[portnum - 1];
743 		if (port_dev && port_dev->child)
744 			pm_wakeup_event(&port_dev->child->dev, 0);
745 
746 		set_bit(portnum, hub->wakeup_bits);
747 		kick_hub_wq(hub);
748 	}
749 }
750 EXPORT_SYMBOL_GPL(usb_wakeup_notification);
751 
752 /* completion function, fires on port status changes and various faults */
hub_irq(struct urb * urb)753 static void hub_irq(struct urb *urb)
754 {
755 	struct usb_hub *hub = urb->context;
756 	int status = urb->status;
757 	unsigned i;
758 	unsigned long bits;
759 
760 	switch (status) {
761 	case -ENOENT:		/* synchronous unlink */
762 	case -ECONNRESET:	/* async unlink */
763 	case -ESHUTDOWN:	/* hardware going away */
764 		return;
765 
766 	default:		/* presumably an error */
767 		/* Cause a hub reset after 10 consecutive errors */
768 		dev_dbg(hub->intfdev, "transfer --> %d\n", status);
769 		if ((++hub->nerrors < 10) || hub->error)
770 			goto resubmit;
771 		hub->error = status;
772 		fallthrough;
773 
774 	/* let hub_wq handle things */
775 	case 0:			/* we got data:  port status changed */
776 		bits = 0;
777 		for (i = 0; i < urb->actual_length; ++i)
778 			bits |= ((unsigned long) ((*hub->buffer)[i]))
779 					<< (i*8);
780 		hub->event_bits[0] = bits;
781 		break;
782 	}
783 
784 	hub->nerrors = 0;
785 
786 	/* Something happened, let hub_wq figure it out */
787 	kick_hub_wq(hub);
788 
789 resubmit:
790 	hub_resubmit_irq_urb(hub);
791 }
792 
793 /* USB 2.0 spec Section 11.24.2.3 */
794 static inline int
hub_clear_tt_buffer(struct usb_device * hdev,u16 devinfo,u16 tt)795 hub_clear_tt_buffer(struct usb_device *hdev, u16 devinfo, u16 tt)
796 {
797 	/* Need to clear both directions for control ep */
798 	if (((devinfo >> 11) & USB_ENDPOINT_XFERTYPE_MASK) ==
799 			USB_ENDPOINT_XFER_CONTROL) {
800 		int status = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
801 				HUB_CLEAR_TT_BUFFER, USB_RT_PORT,
802 				devinfo ^ 0x8000, tt, NULL, 0, 1000);
803 		if (status)
804 			return status;
805 	}
806 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
807 			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
808 			       tt, NULL, 0, 1000);
809 }
810 
811 /*
812  * enumeration blocks hub_wq for a long time. we use keventd instead, since
813  * long blocking there is the exception, not the rule.  accordingly, HCDs
814  * talking to TTs must queue control transfers (not just bulk and iso), so
815  * both can talk to the same hub concurrently.
816  */
hub_tt_work(struct work_struct * work)817 static void hub_tt_work(struct work_struct *work)
818 {
819 	struct usb_hub		*hub =
820 		container_of(work, struct usb_hub, tt.clear_work);
821 	unsigned long		flags;
822 
823 	spin_lock_irqsave(&hub->tt.lock, flags);
824 	while (!list_empty(&hub->tt.clear_list)) {
825 		struct list_head	*next;
826 		struct usb_tt_clear	*clear;
827 		struct usb_device	*hdev = hub->hdev;
828 		const struct hc_driver	*drv;
829 		int			status;
830 
831 		next = hub->tt.clear_list.next;
832 		clear = list_entry(next, struct usb_tt_clear, clear_list);
833 		list_del(&clear->clear_list);
834 
835 		/* drop lock so HCD can concurrently report other TT errors */
836 		spin_unlock_irqrestore(&hub->tt.lock, flags);
837 		status = hub_clear_tt_buffer(hdev, clear->devinfo, clear->tt);
838 		if (status && status != -ENODEV)
839 			dev_err(&hdev->dev,
840 				"clear tt %d (%04x) error %d\n",
841 				clear->tt, clear->devinfo, status);
842 
843 		/* Tell the HCD, even if the operation failed */
844 		drv = clear->hcd->driver;
845 		if (drv->clear_tt_buffer_complete)
846 			(drv->clear_tt_buffer_complete)(clear->hcd, clear->ep);
847 
848 		kfree(clear);
849 		spin_lock_irqsave(&hub->tt.lock, flags);
850 	}
851 	spin_unlock_irqrestore(&hub->tt.lock, flags);
852 }
853 
854 /**
855  * usb_hub_set_port_power - control hub port's power state
856  * @hdev: USB device belonging to the usb hub
857  * @hub: target hub
858  * @port1: port index
859  * @set: expected status
860  *
861  * call this function to control port's power via setting or
862  * clearing the port's PORT_POWER feature.
863  *
864  * Return: 0 if successful. A negative error code otherwise.
865  */
usb_hub_set_port_power(struct usb_device * hdev,struct usb_hub * hub,int port1,bool set)866 int usb_hub_set_port_power(struct usb_device *hdev, struct usb_hub *hub,
867 			   int port1, bool set)
868 {
869 	int ret;
870 
871 	if (set)
872 		ret = set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
873 	else
874 		ret = usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
875 
876 	if (ret)
877 		return ret;
878 
879 	if (set)
880 		set_bit(port1, hub->power_bits);
881 	else
882 		clear_bit(port1, hub->power_bits);
883 	return 0;
884 }
885 
886 /**
887  * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub
888  * @urb: an URB associated with the failed or incomplete split transaction
889  *
890  * High speed HCDs use this to tell the hub driver that some split control or
891  * bulk transaction failed in a way that requires clearing internal state of
892  * a transaction translator.  This is normally detected (and reported) from
893  * interrupt context.
894  *
895  * It may not be possible for that hub to handle additional full (or low)
896  * speed transactions until that state is fully cleared out.
897  *
898  * Return: 0 if successful. A negative error code otherwise.
899  */
usb_hub_clear_tt_buffer(struct urb * urb)900 int usb_hub_clear_tt_buffer(struct urb *urb)
901 {
902 	struct usb_device	*udev = urb->dev;
903 	int			pipe = urb->pipe;
904 	struct usb_tt		*tt = udev->tt;
905 	unsigned long		flags;
906 	struct usb_tt_clear	*clear;
907 
908 	/* we've got to cope with an arbitrary number of pending TT clears,
909 	 * since each TT has "at least two" buffers that can need it (and
910 	 * there can be many TTs per hub).  even if they're uncommon.
911 	 */
912 	clear = kmalloc(sizeof *clear, GFP_ATOMIC);
913 	if (clear == NULL) {
914 		dev_err(&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
915 		/* FIXME recover somehow ... RESET_TT? */
916 		return -ENOMEM;
917 	}
918 
919 	/* info that CLEAR_TT_BUFFER needs */
920 	clear->tt = tt->multi ? udev->ttport : 1;
921 	clear->devinfo = usb_pipeendpoint (pipe);
922 	clear->devinfo |= ((u16)udev->devaddr) << 4;
923 	clear->devinfo |= usb_pipecontrol(pipe)
924 			? (USB_ENDPOINT_XFER_CONTROL << 11)
925 			: (USB_ENDPOINT_XFER_BULK << 11);
926 	if (usb_pipein(pipe))
927 		clear->devinfo |= 1 << 15;
928 
929 	/* info for completion callback */
930 	clear->hcd = bus_to_hcd(udev->bus);
931 	clear->ep = urb->ep;
932 
933 	/* tell keventd to clear state for this TT */
934 	spin_lock_irqsave(&tt->lock, flags);
935 	list_add_tail(&clear->clear_list, &tt->clear_list);
936 	schedule_work(&tt->clear_work);
937 	spin_unlock_irqrestore(&tt->lock, flags);
938 	return 0;
939 }
940 EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer);
941 
hub_power_on(struct usb_hub * hub,bool do_delay)942 static void hub_power_on(struct usb_hub *hub, bool do_delay)
943 {
944 	int port1;
945 
946 	/* Enable power on each port.  Some hubs have reserved values
947 	 * of LPSM (> 2) in their descriptors, even though they are
948 	 * USB 2.0 hubs.  Some hubs do not implement port-power switching
949 	 * but only emulate it.  In all cases, the ports won't work
950 	 * unless we send these messages to the hub.
951 	 */
952 	if (hub_is_port_power_switchable(hub))
953 		dev_dbg(hub->intfdev, "enabling power on all ports\n");
954 	else
955 		dev_dbg(hub->intfdev, "trying to enable port power on "
956 				"non-switchable hub\n");
957 	for (port1 = 1; port1 <= hub->hdev->maxchild; port1++)
958 		if (test_bit(port1, hub->power_bits))
959 			set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
960 		else
961 			usb_clear_port_feature(hub->hdev, port1,
962 						USB_PORT_FEAT_POWER);
963 	if (do_delay)
964 		msleep(hub_power_on_good_delay(hub));
965 }
966 
hub_hub_status(struct usb_hub * hub,u16 * status,u16 * change)967 static int hub_hub_status(struct usb_hub *hub,
968 		u16 *status, u16 *change)
969 {
970 	int ret;
971 
972 	mutex_lock(&hub->status_mutex);
973 	ret = get_hub_status(hub->hdev, &hub->status->hub);
974 	if (ret < 0) {
975 		if (ret != -ENODEV)
976 			dev_err(hub->intfdev,
977 				"%s failed (err = %d)\n", __func__, ret);
978 	} else {
979 		*status = le16_to_cpu(hub->status->hub.wHubStatus);
980 		*change = le16_to_cpu(hub->status->hub.wHubChange);
981 		ret = 0;
982 	}
983 	mutex_unlock(&hub->status_mutex);
984 	return ret;
985 }
986 
hub_set_port_link_state(struct usb_hub * hub,int port1,unsigned int link_status)987 static int hub_set_port_link_state(struct usb_hub *hub, int port1,
988 			unsigned int link_status)
989 {
990 	return set_port_feature(hub->hdev,
991 			port1 | (link_status << 3),
992 			USB_PORT_FEAT_LINK_STATE);
993 }
994 
995 /*
996  * Disable a port and mark a logical connect-change event, so that some
997  * time later hub_wq will disconnect() any existing usb_device on the port
998  * and will re-enumerate if there actually is a device attached.
999  */
hub_port_logical_disconnect(struct usb_hub * hub,int port1)1000 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
1001 {
1002 	dev_dbg(&hub->ports[port1 - 1]->dev, "logical disconnect\n");
1003 	hub_port_disable(hub, port1, 1);
1004 
1005 	/* FIXME let caller ask to power down the port:
1006 	 *  - some devices won't enumerate without a VBUS power cycle
1007 	 *  - SRP saves power that way
1008 	 *  - ... new call, TBD ...
1009 	 * That's easy if this hub can switch power per-port, and
1010 	 * hub_wq reactivates the port later (timer, SRP, etc).
1011 	 * Powerdown must be optional, because of reset/DFU.
1012 	 */
1013 
1014 	set_bit(port1, hub->change_bits);
1015 	kick_hub_wq(hub);
1016 }
1017 
1018 /**
1019  * usb_remove_device - disable a device's port on its parent hub
1020  * @udev: device to be disabled and removed
1021  * Context: @udev locked, must be able to sleep.
1022  *
1023  * After @udev's port has been disabled, hub_wq is notified and it will
1024  * see that the device has been disconnected.  When the device is
1025  * physically unplugged and something is plugged in, the events will
1026  * be received and processed normally.
1027  *
1028  * Return: 0 if successful. A negative error code otherwise.
1029  */
usb_remove_device(struct usb_device * udev)1030 int usb_remove_device(struct usb_device *udev)
1031 {
1032 	struct usb_hub *hub;
1033 	struct usb_interface *intf;
1034 	int ret;
1035 
1036 	if (!udev->parent)	/* Can't remove a root hub */
1037 		return -EINVAL;
1038 	hub = usb_hub_to_struct_hub(udev->parent);
1039 	intf = to_usb_interface(hub->intfdev);
1040 
1041 	ret = usb_autopm_get_interface(intf);
1042 	if (ret < 0)
1043 		return ret;
1044 
1045 	set_bit(udev->portnum, hub->removed_bits);
1046 	hub_port_logical_disconnect(hub, udev->portnum);
1047 	usb_autopm_put_interface(intf);
1048 	return 0;
1049 }
1050 
1051 enum hub_activation_type {
1052 	HUB_INIT, HUB_INIT2, HUB_INIT3,		/* INITs must come first */
1053 	HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
1054 };
1055 
1056 static void hub_init_func2(struct work_struct *ws);
1057 static void hub_init_func3(struct work_struct *ws);
1058 
hub_activate(struct usb_hub * hub,enum hub_activation_type type)1059 static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
1060 {
1061 	struct usb_device *hdev = hub->hdev;
1062 	struct usb_hcd *hcd;
1063 	int ret;
1064 	int port1;
1065 	int status;
1066 	bool need_debounce_delay = false;
1067 	unsigned delay;
1068 
1069 	/* Continue a partial initialization */
1070 	if (type == HUB_INIT2 || type == HUB_INIT3) {
1071 		device_lock(&hdev->dev);
1072 
1073 		/* Was the hub disconnected while we were waiting? */
1074 		if (hub->disconnected)
1075 			goto disconnected;
1076 		if (type == HUB_INIT2)
1077 			goto init2;
1078 		goto init3;
1079 	}
1080 	kref_get(&hub->kref);
1081 
1082 	/* The superspeed hub except for root hub has to use Hub Depth
1083 	 * value as an offset into the route string to locate the bits
1084 	 * it uses to determine the downstream port number. So hub driver
1085 	 * should send a set hub depth request to superspeed hub after
1086 	 * the superspeed hub is set configuration in initialization or
1087 	 * reset procedure.
1088 	 *
1089 	 * After a resume, port power should still be on.
1090 	 * For any other type of activation, turn it on.
1091 	 */
1092 	if (type != HUB_RESUME) {
1093 		if (hdev->parent && hub_is_superspeed(hdev)) {
1094 			ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
1095 					HUB_SET_DEPTH, USB_RT_HUB,
1096 					hdev->level - 1, 0, NULL, 0,
1097 					USB_CTRL_SET_TIMEOUT);
1098 			if (ret < 0)
1099 				dev_err(hub->intfdev,
1100 						"set hub depth failed\n");
1101 		}
1102 
1103 		/* Speed up system boot by using a delayed_work for the
1104 		 * hub's initial power-up delays.  This is pretty awkward
1105 		 * and the implementation looks like a home-brewed sort of
1106 		 * setjmp/longjmp, but it saves at least 100 ms for each
1107 		 * root hub (assuming usbcore is compiled into the kernel
1108 		 * rather than as a module).  It adds up.
1109 		 *
1110 		 * This can't be done for HUB_RESUME or HUB_RESET_RESUME
1111 		 * because for those activation types the ports have to be
1112 		 * operational when we return.  In theory this could be done
1113 		 * for HUB_POST_RESET, but it's easier not to.
1114 		 */
1115 		if (type == HUB_INIT) {
1116 			delay = hub_power_on_good_delay(hub);
1117 
1118 			hub_power_on(hub, false);
1119 			INIT_DELAYED_WORK(&hub->init_work, hub_init_func2);
1120 			queue_delayed_work(system_power_efficient_wq,
1121 					&hub->init_work,
1122 					msecs_to_jiffies(delay));
1123 
1124 			/* Suppress autosuspend until init is done */
1125 			usb_autopm_get_interface_no_resume(
1126 					to_usb_interface(hub->intfdev));
1127 			return;		/* Continues at init2: below */
1128 		} else if (type == HUB_RESET_RESUME) {
1129 			/* The internal host controller state for the hub device
1130 			 * may be gone after a host power loss on system resume.
1131 			 * Update the device's info so the HW knows it's a hub.
1132 			 */
1133 			hcd = bus_to_hcd(hdev->bus);
1134 			if (hcd->driver->update_hub_device) {
1135 				ret = hcd->driver->update_hub_device(hcd, hdev,
1136 						&hub->tt, GFP_NOIO);
1137 				if (ret < 0) {
1138 					dev_err(hub->intfdev,
1139 						"Host not accepting hub info update\n");
1140 					dev_err(hub->intfdev,
1141 						"LS/FS devices and hubs may not work under this hub\n");
1142 				}
1143 			}
1144 			hub_power_on(hub, true);
1145 		} else {
1146 			hub_power_on(hub, true);
1147 		}
1148 	/* Give some time on remote wakeup to let links to transit to U0 */
1149 	} else if (hub_is_superspeed(hub->hdev))
1150 		msleep(20);
1151 
1152  init2:
1153 
1154 	/*
1155 	 * Check each port and set hub->change_bits to let hub_wq know
1156 	 * which ports need attention.
1157 	 */
1158 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
1159 		struct usb_port *port_dev = hub->ports[port1 - 1];
1160 		struct usb_device *udev = port_dev->child;
1161 		u16 portstatus, portchange;
1162 
1163 		portstatus = portchange = 0;
1164 		status = usb_hub_port_status(hub, port1, &portstatus, &portchange);
1165 		if (status)
1166 			goto abort;
1167 
1168 		if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
1169 			dev_dbg(&port_dev->dev, "status %04x change %04x\n",
1170 					portstatus, portchange);
1171 
1172 		/*
1173 		 * After anything other than HUB_RESUME (i.e., initialization
1174 		 * or any sort of reset), every port should be disabled.
1175 		 * Unconnected ports should likewise be disabled (paranoia),
1176 		 * and so should ports for which we have no usb_device.
1177 		 */
1178 		if ((portstatus & USB_PORT_STAT_ENABLE) && (
1179 				type != HUB_RESUME ||
1180 				!(portstatus & USB_PORT_STAT_CONNECTION) ||
1181 				!udev ||
1182 				udev->state == USB_STATE_NOTATTACHED)) {
1183 			/*
1184 			 * USB3 protocol ports will automatically transition
1185 			 * to Enabled state when detect an USB3.0 device attach.
1186 			 * Do not disable USB3 protocol ports, just pretend
1187 			 * power was lost
1188 			 */
1189 			portstatus &= ~USB_PORT_STAT_ENABLE;
1190 			if (!hub_is_superspeed(hdev))
1191 				usb_clear_port_feature(hdev, port1,
1192 						   USB_PORT_FEAT_ENABLE);
1193 		}
1194 
1195 		/* Make sure a warm-reset request is handled by port_event */
1196 		if (type == HUB_RESUME &&
1197 		    hub_port_warm_reset_required(hub, port1, portstatus))
1198 			set_bit(port1, hub->event_bits);
1199 
1200 		/*
1201 		 * Add debounce if USB3 link is in polling/link training state.
1202 		 * Link will automatically transition to Enabled state after
1203 		 * link training completes.
1204 		 */
1205 		if (hub_is_superspeed(hdev) &&
1206 		    ((portstatus & USB_PORT_STAT_LINK_STATE) ==
1207 						USB_SS_PORT_LS_POLLING))
1208 			need_debounce_delay = true;
1209 
1210 		/* Clear status-change flags; we'll debounce later */
1211 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
1212 			need_debounce_delay = true;
1213 			usb_clear_port_feature(hub->hdev, port1,
1214 					USB_PORT_FEAT_C_CONNECTION);
1215 		}
1216 		if (portchange & USB_PORT_STAT_C_ENABLE) {
1217 			need_debounce_delay = true;
1218 			usb_clear_port_feature(hub->hdev, port1,
1219 					USB_PORT_FEAT_C_ENABLE);
1220 		}
1221 		if (portchange & USB_PORT_STAT_C_RESET) {
1222 			need_debounce_delay = true;
1223 			usb_clear_port_feature(hub->hdev, port1,
1224 					USB_PORT_FEAT_C_RESET);
1225 		}
1226 		if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
1227 				hub_is_superspeed(hub->hdev)) {
1228 			need_debounce_delay = true;
1229 			usb_clear_port_feature(hub->hdev, port1,
1230 					USB_PORT_FEAT_C_BH_PORT_RESET);
1231 		}
1232 		/* We can forget about a "removed" device when there's a
1233 		 * physical disconnect or the connect status changes.
1234 		 */
1235 		if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
1236 				(portchange & USB_PORT_STAT_C_CONNECTION))
1237 			clear_bit(port1, hub->removed_bits);
1238 
1239 		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
1240 			/* Tell hub_wq to disconnect the device or
1241 			 * check for a new connection or over current condition.
1242 			 * Based on USB2.0 Spec Section 11.12.5,
1243 			 * C_PORT_OVER_CURRENT could be set while
1244 			 * PORT_OVER_CURRENT is not. So check for any of them.
1245 			 */
1246 			if (udev || (portstatus & USB_PORT_STAT_CONNECTION) ||
1247 			    (portchange & USB_PORT_STAT_C_CONNECTION) ||
1248 			    (portstatus & USB_PORT_STAT_OVERCURRENT) ||
1249 			    (portchange & USB_PORT_STAT_C_OVERCURRENT))
1250 				set_bit(port1, hub->change_bits);
1251 
1252 		} else if (portstatus & USB_PORT_STAT_ENABLE) {
1253 			bool port_resumed = (portstatus &
1254 					USB_PORT_STAT_LINK_STATE) ==
1255 				USB_SS_PORT_LS_U0;
1256 			/* The power session apparently survived the resume.
1257 			 * If there was an overcurrent or suspend change
1258 			 * (i.e., remote wakeup request), have hub_wq
1259 			 * take care of it.  Look at the port link state
1260 			 * for USB 3.0 hubs, since they don't have a suspend
1261 			 * change bit, and they don't set the port link change
1262 			 * bit on device-initiated resume.
1263 			 */
1264 			if (portchange || (hub_is_superspeed(hub->hdev) &&
1265 						port_resumed))
1266 				set_bit(port1, hub->event_bits);
1267 
1268 		} else if (udev->persist_enabled) {
1269 #ifdef CONFIG_PM
1270 			udev->reset_resume = 1;
1271 #endif
1272 			/* Don't set the change_bits when the device
1273 			 * was powered off.
1274 			 */
1275 			if (test_bit(port1, hub->power_bits))
1276 				set_bit(port1, hub->change_bits);
1277 
1278 		} else {
1279 			/* The power session is gone; tell hub_wq */
1280 			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1281 			set_bit(port1, hub->change_bits);
1282 		}
1283 	}
1284 
1285 	/* If no port-status-change flags were set, we don't need any
1286 	 * debouncing.  If flags were set we can try to debounce the
1287 	 * ports all at once right now, instead of letting hub_wq do them
1288 	 * one at a time later on.
1289 	 *
1290 	 * If any port-status changes do occur during this delay, hub_wq
1291 	 * will see them later and handle them normally.
1292 	 */
1293 	if (need_debounce_delay) {
1294 		delay = HUB_DEBOUNCE_STABLE;
1295 
1296 		/* Don't do a long sleep inside a workqueue routine */
1297 		if (type == HUB_INIT2) {
1298 			INIT_DELAYED_WORK(&hub->init_work, hub_init_func3);
1299 			queue_delayed_work(system_power_efficient_wq,
1300 					&hub->init_work,
1301 					msecs_to_jiffies(delay));
1302 			device_unlock(&hdev->dev);
1303 			return;		/* Continues at init3: below */
1304 		} else {
1305 			msleep(delay);
1306 		}
1307 	}
1308  init3:
1309 	hub->quiescing = 0;
1310 
1311 	status = usb_submit_urb(hub->urb, GFP_NOIO);
1312 	if (status < 0)
1313 		dev_err(hub->intfdev, "activate --> %d\n", status);
1314 	if (hub->has_indicators && blinkenlights)
1315 		queue_delayed_work(system_power_efficient_wq,
1316 				&hub->leds, LED_CYCLE_PERIOD);
1317 
1318 	/* Scan all ports that need attention */
1319 	kick_hub_wq(hub);
1320  abort:
1321 	if (type == HUB_INIT2 || type == HUB_INIT3) {
1322 		/* Allow autosuspend if it was suppressed */
1323  disconnected:
1324 		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
1325 		device_unlock(&hdev->dev);
1326 	}
1327 
1328 	kref_put(&hub->kref, hub_release);
1329 }
1330 
1331 /* Implement the continuations for the delays above */
hub_init_func2(struct work_struct * ws)1332 static void hub_init_func2(struct work_struct *ws)
1333 {
1334 	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1335 
1336 	hub_activate(hub, HUB_INIT2);
1337 }
1338 
hub_init_func3(struct work_struct * ws)1339 static void hub_init_func3(struct work_struct *ws)
1340 {
1341 	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1342 
1343 	hub_activate(hub, HUB_INIT3);
1344 }
1345 
1346 enum hub_quiescing_type {
1347 	HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
1348 };
1349 
hub_quiesce(struct usb_hub * hub,enum hub_quiescing_type type)1350 static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
1351 {
1352 	struct usb_device *hdev = hub->hdev;
1353 	unsigned long flags;
1354 	int i;
1355 
1356 	/* hub_wq and related activity won't re-trigger */
1357 	spin_lock_irqsave(&hub->irq_urb_lock, flags);
1358 	hub->quiescing = 1;
1359 	spin_unlock_irqrestore(&hub->irq_urb_lock, flags);
1360 
1361 	if (type != HUB_SUSPEND) {
1362 		/* Disconnect all the children */
1363 		for (i = 0; i < hdev->maxchild; ++i) {
1364 			if (hub->ports[i]->child)
1365 				usb_disconnect(&hub->ports[i]->child);
1366 		}
1367 	}
1368 
1369 	/* Stop hub_wq and related activity */
1370 	del_timer_sync(&hub->irq_urb_retry);
1371 	usb_kill_urb(hub->urb);
1372 	if (hub->has_indicators)
1373 		cancel_delayed_work_sync(&hub->leds);
1374 	if (hub->tt.hub)
1375 		flush_work(&hub->tt.clear_work);
1376 }
1377 
hub_pm_barrier_for_all_ports(struct usb_hub * hub)1378 static void hub_pm_barrier_for_all_ports(struct usb_hub *hub)
1379 {
1380 	int i;
1381 
1382 	for (i = 0; i < hub->hdev->maxchild; ++i)
1383 		pm_runtime_barrier(&hub->ports[i]->dev);
1384 }
1385 
1386 /* caller has locked the hub device */
hub_pre_reset(struct usb_interface * intf)1387 static int hub_pre_reset(struct usb_interface *intf)
1388 {
1389 	struct usb_hub *hub = usb_get_intfdata(intf);
1390 
1391 	hub_quiesce(hub, HUB_PRE_RESET);
1392 	hub->in_reset = 1;
1393 	hub_pm_barrier_for_all_ports(hub);
1394 	return 0;
1395 }
1396 
1397 /* caller has locked the hub device */
hub_post_reset(struct usb_interface * intf)1398 static int hub_post_reset(struct usb_interface *intf)
1399 {
1400 	struct usb_hub *hub = usb_get_intfdata(intf);
1401 
1402 	hub->in_reset = 0;
1403 	hub_pm_barrier_for_all_ports(hub);
1404 	hub_activate(hub, HUB_POST_RESET);
1405 	return 0;
1406 }
1407 
hub_configure(struct usb_hub * hub,struct usb_endpoint_descriptor * endpoint)1408 static int hub_configure(struct usb_hub *hub,
1409 	struct usb_endpoint_descriptor *endpoint)
1410 {
1411 	struct usb_hcd *hcd;
1412 	struct usb_device *hdev = hub->hdev;
1413 	struct device *hub_dev = hub->intfdev;
1414 	u16 hubstatus, hubchange;
1415 	u16 wHubCharacteristics;
1416 	unsigned int pipe;
1417 	int maxp, ret, i;
1418 	char *message = "out of memory";
1419 	unsigned unit_load;
1420 	unsigned full_load;
1421 	unsigned maxchild;
1422 
1423 	hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
1424 	if (!hub->buffer) {
1425 		ret = -ENOMEM;
1426 		goto fail;
1427 	}
1428 
1429 	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
1430 	if (!hub->status) {
1431 		ret = -ENOMEM;
1432 		goto fail;
1433 	}
1434 	mutex_init(&hub->status_mutex);
1435 
1436 	hub->descriptor = kzalloc(sizeof(*hub->descriptor), GFP_KERNEL);
1437 	if (!hub->descriptor) {
1438 		ret = -ENOMEM;
1439 		goto fail;
1440 	}
1441 
1442 	/* Request the entire hub descriptor.
1443 	 * hub->descriptor can handle USB_MAXCHILDREN ports,
1444 	 * but a (non-SS) hub can/will return fewer bytes here.
1445 	 */
1446 	ret = get_hub_descriptor(hdev, hub->descriptor);
1447 	if (ret < 0) {
1448 		message = "can't read hub descriptor";
1449 		goto fail;
1450 	}
1451 
1452 	maxchild = USB_MAXCHILDREN;
1453 	if (hub_is_superspeed(hdev))
1454 		maxchild = min_t(unsigned, maxchild, USB_SS_MAXPORTS);
1455 
1456 	if (hub->descriptor->bNbrPorts > maxchild) {
1457 		message = "hub has too many ports!";
1458 		ret = -ENODEV;
1459 		goto fail;
1460 	} else if (hub->descriptor->bNbrPorts == 0) {
1461 		message = "hub doesn't have any ports!";
1462 		ret = -ENODEV;
1463 		goto fail;
1464 	}
1465 
1466 	/*
1467 	 * Accumulate wHubDelay + 40ns for every hub in the tree of devices.
1468 	 * The resulting value will be used for SetIsochDelay() request.
1469 	 */
1470 	if (hub_is_superspeed(hdev) || hub_is_superspeedplus(hdev)) {
1471 		u32 delay = __le16_to_cpu(hub->descriptor->u.ss.wHubDelay);
1472 
1473 		if (hdev->parent)
1474 			delay += hdev->parent->hub_delay;
1475 
1476 		delay += USB_TP_TRANSMISSION_DELAY;
1477 		hdev->hub_delay = min_t(u32, delay, USB_TP_TRANSMISSION_DELAY_MAX);
1478 	}
1479 
1480 	maxchild = hub->descriptor->bNbrPorts;
1481 	dev_info(hub_dev, "%d port%s detected\n", maxchild,
1482 			(maxchild == 1) ? "" : "s");
1483 
1484 	hub->ports = kcalloc(maxchild, sizeof(struct usb_port *), GFP_KERNEL);
1485 	if (!hub->ports) {
1486 		ret = -ENOMEM;
1487 		goto fail;
1488 	}
1489 
1490 	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
1491 	if (hub_is_superspeed(hdev)) {
1492 		unit_load = 150;
1493 		full_load = 900;
1494 	} else {
1495 		unit_load = 100;
1496 		full_load = 500;
1497 	}
1498 
1499 	/* FIXME for USB 3.0, skip for now */
1500 	if ((wHubCharacteristics & HUB_CHAR_COMPOUND) &&
1501 			!(hub_is_superspeed(hdev))) {
1502 		char	portstr[USB_MAXCHILDREN + 1];
1503 
1504 		for (i = 0; i < maxchild; i++)
1505 			portstr[i] = hub->descriptor->u.hs.DeviceRemovable
1506 				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
1507 				? 'F' : 'R';
1508 		portstr[maxchild] = 0;
1509 		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
1510 	} else
1511 		dev_dbg(hub_dev, "standalone hub\n");
1512 
1513 	switch (wHubCharacteristics & HUB_CHAR_LPSM) {
1514 	case HUB_CHAR_COMMON_LPSM:
1515 		dev_dbg(hub_dev, "ganged power switching\n");
1516 		break;
1517 	case HUB_CHAR_INDV_PORT_LPSM:
1518 		dev_dbg(hub_dev, "individual port power switching\n");
1519 		break;
1520 	case HUB_CHAR_NO_LPSM:
1521 	case HUB_CHAR_LPSM:
1522 		dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
1523 		break;
1524 	}
1525 
1526 	switch (wHubCharacteristics & HUB_CHAR_OCPM) {
1527 	case HUB_CHAR_COMMON_OCPM:
1528 		dev_dbg(hub_dev, "global over-current protection\n");
1529 		break;
1530 	case HUB_CHAR_INDV_PORT_OCPM:
1531 		dev_dbg(hub_dev, "individual port over-current protection\n");
1532 		break;
1533 	case HUB_CHAR_NO_OCPM:
1534 	case HUB_CHAR_OCPM:
1535 		dev_dbg(hub_dev, "no over-current protection\n");
1536 		break;
1537 	}
1538 
1539 	spin_lock_init(&hub->tt.lock);
1540 	INIT_LIST_HEAD(&hub->tt.clear_list);
1541 	INIT_WORK(&hub->tt.clear_work, hub_tt_work);
1542 	switch (hdev->descriptor.bDeviceProtocol) {
1543 	case USB_HUB_PR_FS:
1544 		break;
1545 	case USB_HUB_PR_HS_SINGLE_TT:
1546 		dev_dbg(hub_dev, "Single TT\n");
1547 		hub->tt.hub = hdev;
1548 		break;
1549 	case USB_HUB_PR_HS_MULTI_TT:
1550 		ret = usb_set_interface(hdev, 0, 1);
1551 		if (ret == 0) {
1552 			dev_dbg(hub_dev, "TT per port\n");
1553 			hub->tt.multi = 1;
1554 		} else
1555 			dev_err(hub_dev, "Using single TT (err %d)\n",
1556 				ret);
1557 		hub->tt.hub = hdev;
1558 		break;
1559 	case USB_HUB_PR_SS:
1560 		/* USB 3.0 hubs don't have a TT */
1561 		break;
1562 	default:
1563 		dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
1564 			hdev->descriptor.bDeviceProtocol);
1565 		break;
1566 	}
1567 
1568 	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
1569 	switch (wHubCharacteristics & HUB_CHAR_TTTT) {
1570 	case HUB_TTTT_8_BITS:
1571 		if (hdev->descriptor.bDeviceProtocol != 0) {
1572 			hub->tt.think_time = 666;
1573 			dev_dbg(hub_dev, "TT requires at most %d "
1574 					"FS bit times (%d ns)\n",
1575 				8, hub->tt.think_time);
1576 		}
1577 		break;
1578 	case HUB_TTTT_16_BITS:
1579 		hub->tt.think_time = 666 * 2;
1580 		dev_dbg(hub_dev, "TT requires at most %d "
1581 				"FS bit times (%d ns)\n",
1582 			16, hub->tt.think_time);
1583 		break;
1584 	case HUB_TTTT_24_BITS:
1585 		hub->tt.think_time = 666 * 3;
1586 		dev_dbg(hub_dev, "TT requires at most %d "
1587 				"FS bit times (%d ns)\n",
1588 			24, hub->tt.think_time);
1589 		break;
1590 	case HUB_TTTT_32_BITS:
1591 		hub->tt.think_time = 666 * 4;
1592 		dev_dbg(hub_dev, "TT requires at most %d "
1593 				"FS bit times (%d ns)\n",
1594 			32, hub->tt.think_time);
1595 		break;
1596 	}
1597 
1598 	/* probe() zeroes hub->indicator[] */
1599 	if (wHubCharacteristics & HUB_CHAR_PORTIND) {
1600 		hub->has_indicators = 1;
1601 		dev_dbg(hub_dev, "Port indicators are supported\n");
1602 	}
1603 
1604 	dev_dbg(hub_dev, "power on to power good time: %dms\n",
1605 		hub->descriptor->bPwrOn2PwrGood * 2);
1606 
1607 	/* power budgeting mostly matters with bus-powered hubs,
1608 	 * and battery-powered root hubs (may provide just 8 mA).
1609 	 */
1610 	ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
1611 	if (ret) {
1612 		message = "can't get hub status";
1613 		goto fail;
1614 	}
1615 	hcd = bus_to_hcd(hdev->bus);
1616 	if (hdev == hdev->bus->root_hub) {
1617 		if (hcd->power_budget > 0)
1618 			hdev->bus_mA = hcd->power_budget;
1619 		else
1620 			hdev->bus_mA = full_load * maxchild;
1621 		if (hdev->bus_mA >= full_load)
1622 			hub->mA_per_port = full_load;
1623 		else {
1624 			hub->mA_per_port = hdev->bus_mA;
1625 			hub->limited_power = 1;
1626 		}
1627 	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
1628 		int remaining = hdev->bus_mA -
1629 			hub->descriptor->bHubContrCurrent;
1630 
1631 		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
1632 			hub->descriptor->bHubContrCurrent);
1633 		hub->limited_power = 1;
1634 
1635 		if (remaining < maxchild * unit_load)
1636 			dev_warn(hub_dev,
1637 					"insufficient power available "
1638 					"to use all downstream ports\n");
1639 		hub->mA_per_port = unit_load;	/* 7.2.1 */
1640 
1641 	} else {	/* Self-powered external hub */
1642 		/* FIXME: What about battery-powered external hubs that
1643 		 * provide less current per port? */
1644 		hub->mA_per_port = full_load;
1645 	}
1646 	if (hub->mA_per_port < full_load)
1647 		dev_dbg(hub_dev, "%umA bus power budget for each child\n",
1648 				hub->mA_per_port);
1649 
1650 	ret = hub_hub_status(hub, &hubstatus, &hubchange);
1651 	if (ret < 0) {
1652 		message = "can't get hub status";
1653 		goto fail;
1654 	}
1655 
1656 	/* local power status reports aren't always correct */
1657 	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
1658 		dev_dbg(hub_dev, "local power source is %s\n",
1659 			(hubstatus & HUB_STATUS_LOCAL_POWER)
1660 			? "lost (inactive)" : "good");
1661 
1662 	if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
1663 		dev_dbg(hub_dev, "%sover-current condition exists\n",
1664 			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
1665 
1666 	/* set up the interrupt endpoint
1667 	 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
1668 	 * bytes as USB2.0[11.12.3] says because some hubs are known
1669 	 * to send more data (and thus cause overflow). For root hubs,
1670 	 * maxpktsize is defined in hcd.c's fake endpoint descriptors
1671 	 * to be big enough for at least USB_MAXCHILDREN ports. */
1672 	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
1673 	maxp = usb_maxpacket(hdev, pipe);
1674 
1675 	if (maxp > sizeof(*hub->buffer))
1676 		maxp = sizeof(*hub->buffer);
1677 
1678 	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
1679 	if (!hub->urb) {
1680 		ret = -ENOMEM;
1681 		goto fail;
1682 	}
1683 
1684 	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
1685 		hub, endpoint->bInterval);
1686 
1687 	/* maybe cycle the hub leds */
1688 	if (hub->has_indicators && blinkenlights)
1689 		hub->indicator[0] = INDICATOR_CYCLE;
1690 
1691 	mutex_lock(&usb_port_peer_mutex);
1692 	for (i = 0; i < maxchild; i++) {
1693 		ret = usb_hub_create_port_device(hub, i + 1);
1694 		if (ret < 0) {
1695 			dev_err(hub->intfdev,
1696 				"couldn't create port%d device.\n", i + 1);
1697 			break;
1698 		}
1699 	}
1700 	hdev->maxchild = i;
1701 	for (i = 0; i < hdev->maxchild; i++) {
1702 		struct usb_port *port_dev = hub->ports[i];
1703 
1704 		pm_runtime_put(&port_dev->dev);
1705 	}
1706 
1707 	mutex_unlock(&usb_port_peer_mutex);
1708 	if (ret < 0)
1709 		goto fail;
1710 
1711 	/* Update the HCD's internal representation of this hub before hub_wq
1712 	 * starts getting port status changes for devices under the hub.
1713 	 */
1714 	if (hcd->driver->update_hub_device) {
1715 		ret = hcd->driver->update_hub_device(hcd, hdev,
1716 				&hub->tt, GFP_KERNEL);
1717 		if (ret < 0) {
1718 			message = "can't update HCD hub info";
1719 			goto fail;
1720 		}
1721 	}
1722 
1723 	usb_hub_adjust_deviceremovable(hdev, hub->descriptor);
1724 
1725 	hub_activate(hub, HUB_INIT);
1726 	return 0;
1727 
1728 fail:
1729 	dev_err(hub_dev, "config failed, %s (err %d)\n",
1730 			message, ret);
1731 	/* hub_disconnect() frees urb and descriptor */
1732 	return ret;
1733 }
1734 
hub_release(struct kref * kref)1735 static void hub_release(struct kref *kref)
1736 {
1737 	struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
1738 
1739 	usb_put_dev(hub->hdev);
1740 	usb_put_intf(to_usb_interface(hub->intfdev));
1741 	kfree(hub);
1742 }
1743 
1744 static unsigned highspeed_hubs;
1745 
hub_disconnect(struct usb_interface * intf)1746 static void hub_disconnect(struct usb_interface *intf)
1747 {
1748 	struct usb_hub *hub = usb_get_intfdata(intf);
1749 	struct usb_device *hdev = interface_to_usbdev(intf);
1750 	int port1;
1751 
1752 	/*
1753 	 * Stop adding new hub events. We do not want to block here and thus
1754 	 * will not try to remove any pending work item.
1755 	 */
1756 	hub->disconnected = 1;
1757 
1758 	/* Disconnect all children and quiesce the hub */
1759 	hub->error = 0;
1760 	hub_quiesce(hub, HUB_DISCONNECT);
1761 
1762 	mutex_lock(&usb_port_peer_mutex);
1763 
1764 	/* Avoid races with recursively_mark_NOTATTACHED() */
1765 	spin_lock_irq(&device_state_lock);
1766 	port1 = hdev->maxchild;
1767 	hdev->maxchild = 0;
1768 	usb_set_intfdata(intf, NULL);
1769 	spin_unlock_irq(&device_state_lock);
1770 
1771 	for (; port1 > 0; --port1)
1772 		usb_hub_remove_port_device(hub, port1);
1773 
1774 	mutex_unlock(&usb_port_peer_mutex);
1775 
1776 	if (hub->hdev->speed == USB_SPEED_HIGH)
1777 		highspeed_hubs--;
1778 
1779 	usb_free_urb(hub->urb);
1780 	kfree(hub->ports);
1781 	kfree(hub->descriptor);
1782 	kfree(hub->status);
1783 	kfree(hub->buffer);
1784 
1785 	pm_suspend_ignore_children(&intf->dev, false);
1786 
1787 	if (hub->quirk_disable_autosuspend)
1788 		usb_autopm_put_interface(intf);
1789 
1790 	onboard_hub_destroy_pdevs(&hub->onboard_hub_devs);
1791 
1792 	kref_put(&hub->kref, hub_release);
1793 }
1794 
hub_descriptor_is_sane(struct usb_host_interface * desc)1795 static bool hub_descriptor_is_sane(struct usb_host_interface *desc)
1796 {
1797 	/* Some hubs have a subclass of 1, which AFAICT according to the */
1798 	/*  specs is not defined, but it works */
1799 	if (desc->desc.bInterfaceSubClass != 0 &&
1800 	    desc->desc.bInterfaceSubClass != 1)
1801 		return false;
1802 
1803 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
1804 	if (desc->desc.bNumEndpoints != 1)
1805 		return false;
1806 
1807 	/* If the first endpoint is not interrupt IN, we'd better punt! */
1808 	if (!usb_endpoint_is_int_in(&desc->endpoint[0].desc))
1809 		return false;
1810 
1811         return true;
1812 }
1813 
hub_probe(struct usb_interface * intf,const struct usb_device_id * id)1814 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
1815 {
1816 	struct usb_host_interface *desc;
1817 	struct usb_device *hdev;
1818 	struct usb_hub *hub;
1819 
1820 	desc = intf->cur_altsetting;
1821 	hdev = interface_to_usbdev(intf);
1822 
1823 	/*
1824 	 * Set default autosuspend delay as 0 to speedup bus suspend,
1825 	 * based on the below considerations:
1826 	 *
1827 	 * - Unlike other drivers, the hub driver does not rely on the
1828 	 *   autosuspend delay to provide enough time to handle a wakeup
1829 	 *   event, and the submitted status URB is just to check future
1830 	 *   change on hub downstream ports, so it is safe to do it.
1831 	 *
1832 	 * - The patch might cause one or more auto supend/resume for
1833 	 *   below very rare devices when they are plugged into hub
1834 	 *   first time:
1835 	 *
1836 	 *   	devices having trouble initializing, and disconnect
1837 	 *   	themselves from the bus and then reconnect a second
1838 	 *   	or so later
1839 	 *
1840 	 *   	devices just for downloading firmware, and disconnects
1841 	 *   	themselves after completing it
1842 	 *
1843 	 *   For these quite rare devices, their drivers may change the
1844 	 *   autosuspend delay of their parent hub in the probe() to one
1845 	 *   appropriate value to avoid the subtle problem if someone
1846 	 *   does care it.
1847 	 *
1848 	 * - The patch may cause one or more auto suspend/resume on
1849 	 *   hub during running 'lsusb', but it is probably too
1850 	 *   infrequent to worry about.
1851 	 *
1852 	 * - Change autosuspend delay of hub can avoid unnecessary auto
1853 	 *   suspend timer for hub, also may decrease power consumption
1854 	 *   of USB bus.
1855 	 *
1856 	 * - If user has indicated to prevent autosuspend by passing
1857 	 *   usbcore.autosuspend = -1 then keep autosuspend disabled.
1858 	 */
1859 #ifdef CONFIG_PM
1860 	if (hdev->dev.power.autosuspend_delay >= 0)
1861 		pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
1862 #endif
1863 
1864 	/*
1865 	 * Hubs have proper suspend/resume support, except for root hubs
1866 	 * where the controller driver doesn't have bus_suspend and
1867 	 * bus_resume methods.
1868 	 */
1869 	if (hdev->parent) {		/* normal device */
1870 		usb_enable_autosuspend(hdev);
1871 	} else {			/* root hub */
1872 		const struct hc_driver *drv = bus_to_hcd(hdev->bus)->driver;
1873 
1874 		if (drv->bus_suspend && drv->bus_resume)
1875 			usb_enable_autosuspend(hdev);
1876 	}
1877 
1878 	if (hdev->level == MAX_TOPO_LEVEL) {
1879 		dev_err(&intf->dev,
1880 			"Unsupported bus topology: hub nested too deep\n");
1881 		return -E2BIG;
1882 	}
1883 
1884 #ifdef	CONFIG_USB_OTG_DISABLE_EXTERNAL_HUB
1885 	if (hdev->parent) {
1886 		dev_warn(&intf->dev, "ignoring external hub\n");
1887 		return -ENODEV;
1888 	}
1889 #endif
1890 
1891 	if (!hub_descriptor_is_sane(desc)) {
1892 		dev_err(&intf->dev, "bad descriptor, ignoring hub\n");
1893 		return -EIO;
1894 	}
1895 
1896 	/* We found a hub */
1897 	dev_info(&intf->dev, "USB hub found\n");
1898 
1899 	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
1900 	if (!hub)
1901 		return -ENOMEM;
1902 
1903 	kref_init(&hub->kref);
1904 	hub->intfdev = &intf->dev;
1905 	hub->hdev = hdev;
1906 	INIT_DELAYED_WORK(&hub->leds, led_work);
1907 	INIT_DELAYED_WORK(&hub->init_work, NULL);
1908 	INIT_WORK(&hub->events, hub_event);
1909 	INIT_LIST_HEAD(&hub->onboard_hub_devs);
1910 	spin_lock_init(&hub->irq_urb_lock);
1911 	timer_setup(&hub->irq_urb_retry, hub_retry_irq_urb, 0);
1912 	usb_get_intf(intf);
1913 	usb_get_dev(hdev);
1914 
1915 	usb_set_intfdata(intf, hub);
1916 	intf->needs_remote_wakeup = 1;
1917 	pm_suspend_ignore_children(&intf->dev, true);
1918 
1919 	if (hdev->speed == USB_SPEED_HIGH)
1920 		highspeed_hubs++;
1921 
1922 	if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
1923 		hub->quirk_check_port_auto_suspend = 1;
1924 
1925 	if (id->driver_info & HUB_QUIRK_DISABLE_AUTOSUSPEND) {
1926 		hub->quirk_disable_autosuspend = 1;
1927 		usb_autopm_get_interface_no_resume(intf);
1928 	}
1929 
1930 	if (hub_configure(hub, &desc->endpoint[0].desc) >= 0) {
1931 		onboard_hub_create_pdevs(hdev, &hub->onboard_hub_devs);
1932 
1933 		return 0;
1934 	}
1935 
1936 	hub_disconnect(intf);
1937 	return -ENODEV;
1938 }
1939 
1940 static int
hub_ioctl(struct usb_interface * intf,unsigned int code,void * user_data)1941 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
1942 {
1943 	struct usb_device *hdev = interface_to_usbdev(intf);
1944 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1945 
1946 	/* assert ifno == 0 (part of hub spec) */
1947 	switch (code) {
1948 	case USBDEVFS_HUB_PORTINFO: {
1949 		struct usbdevfs_hub_portinfo *info = user_data;
1950 		int i;
1951 
1952 		spin_lock_irq(&device_state_lock);
1953 		if (hdev->devnum <= 0)
1954 			info->nports = 0;
1955 		else {
1956 			info->nports = hdev->maxchild;
1957 			for (i = 0; i < info->nports; i++) {
1958 				if (hub->ports[i]->child == NULL)
1959 					info->port[i] = 0;
1960 				else
1961 					info->port[i] =
1962 						hub->ports[i]->child->devnum;
1963 			}
1964 		}
1965 		spin_unlock_irq(&device_state_lock);
1966 
1967 		return info->nports + 1;
1968 		}
1969 
1970 	default:
1971 		return -ENOSYS;
1972 	}
1973 }
1974 
1975 /*
1976  * Allow user programs to claim ports on a hub.  When a device is attached
1977  * to one of these "claimed" ports, the program will "own" the device.
1978  */
find_port_owner(struct usb_device * hdev,unsigned port1,struct usb_dev_state *** ppowner)1979 static int find_port_owner(struct usb_device *hdev, unsigned port1,
1980 		struct usb_dev_state ***ppowner)
1981 {
1982 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1983 
1984 	if (hdev->state == USB_STATE_NOTATTACHED)
1985 		return -ENODEV;
1986 	if (port1 == 0 || port1 > hdev->maxchild)
1987 		return -EINVAL;
1988 
1989 	/* Devices not managed by the hub driver
1990 	 * will always have maxchild equal to 0.
1991 	 */
1992 	*ppowner = &(hub->ports[port1 - 1]->port_owner);
1993 	return 0;
1994 }
1995 
1996 /* In the following three functions, the caller must hold hdev's lock */
usb_hub_claim_port(struct usb_device * hdev,unsigned port1,struct usb_dev_state * owner)1997 int usb_hub_claim_port(struct usb_device *hdev, unsigned port1,
1998 		       struct usb_dev_state *owner)
1999 {
2000 	int rc;
2001 	struct usb_dev_state **powner;
2002 
2003 	rc = find_port_owner(hdev, port1, &powner);
2004 	if (rc)
2005 		return rc;
2006 	if (*powner)
2007 		return -EBUSY;
2008 	*powner = owner;
2009 	return rc;
2010 }
2011 EXPORT_SYMBOL_GPL(usb_hub_claim_port);
2012 
usb_hub_release_port(struct usb_device * hdev,unsigned port1,struct usb_dev_state * owner)2013 int usb_hub_release_port(struct usb_device *hdev, unsigned port1,
2014 			 struct usb_dev_state *owner)
2015 {
2016 	int rc;
2017 	struct usb_dev_state **powner;
2018 
2019 	rc = find_port_owner(hdev, port1, &powner);
2020 	if (rc)
2021 		return rc;
2022 	if (*powner != owner)
2023 		return -ENOENT;
2024 	*powner = NULL;
2025 	return rc;
2026 }
2027 EXPORT_SYMBOL_GPL(usb_hub_release_port);
2028 
usb_hub_release_all_ports(struct usb_device * hdev,struct usb_dev_state * owner)2029 void usb_hub_release_all_ports(struct usb_device *hdev, struct usb_dev_state *owner)
2030 {
2031 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
2032 	int n;
2033 
2034 	for (n = 0; n < hdev->maxchild; n++) {
2035 		if (hub->ports[n]->port_owner == owner)
2036 			hub->ports[n]->port_owner = NULL;
2037 	}
2038 
2039 }
2040 
2041 /* The caller must hold udev's lock */
usb_device_is_owned(struct usb_device * udev)2042 bool usb_device_is_owned(struct usb_device *udev)
2043 {
2044 	struct usb_hub *hub;
2045 
2046 	if (udev->state == USB_STATE_NOTATTACHED || !udev->parent)
2047 		return false;
2048 	hub = usb_hub_to_struct_hub(udev->parent);
2049 	return !!hub->ports[udev->portnum - 1]->port_owner;
2050 }
2051 
update_port_device_state(struct usb_device * udev)2052 static void update_port_device_state(struct usb_device *udev)
2053 {
2054 	struct usb_hub *hub;
2055 	struct usb_port *port_dev;
2056 
2057 	if (udev->parent) {
2058 		hub = usb_hub_to_struct_hub(udev->parent);
2059 		port_dev = hub->ports[udev->portnum - 1];
2060 		WRITE_ONCE(port_dev->state, udev->state);
2061 		sysfs_notify_dirent(port_dev->state_kn);
2062 	}
2063 }
2064 
recursively_mark_NOTATTACHED(struct usb_device * udev)2065 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
2066 {
2067 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
2068 	int i;
2069 
2070 	for (i = 0; i < udev->maxchild; ++i) {
2071 		if (hub->ports[i]->child)
2072 			recursively_mark_NOTATTACHED(hub->ports[i]->child);
2073 	}
2074 	if (udev->state == USB_STATE_SUSPENDED)
2075 		udev->active_duration -= jiffies;
2076 	udev->state = USB_STATE_NOTATTACHED;
2077 	update_port_device_state(udev);
2078 }
2079 
2080 /**
2081  * usb_set_device_state - change a device's current state (usbcore, hcds)
2082  * @udev: pointer to device whose state should be changed
2083  * @new_state: new state value to be stored
2084  *
2085  * udev->state is _not_ fully protected by the device lock.  Although
2086  * most transitions are made only while holding the lock, the state can
2087  * can change to USB_STATE_NOTATTACHED at almost any time.  This
2088  * is so that devices can be marked as disconnected as soon as possible,
2089  * without having to wait for any semaphores to be released.  As a result,
2090  * all changes to any device's state must be protected by the
2091  * device_state_lock spinlock.
2092  *
2093  * Once a device has been added to the device tree, all changes to its state
2094  * should be made using this routine.  The state should _not_ be set directly.
2095  *
2096  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
2097  * Otherwise udev->state is set to new_state, and if new_state is
2098  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
2099  * to USB_STATE_NOTATTACHED.
2100  */
usb_set_device_state(struct usb_device * udev,enum usb_device_state new_state)2101 void usb_set_device_state(struct usb_device *udev,
2102 		enum usb_device_state new_state)
2103 {
2104 	unsigned long flags;
2105 	int wakeup = -1;
2106 
2107 	spin_lock_irqsave(&device_state_lock, flags);
2108 	if (udev->state == USB_STATE_NOTATTACHED)
2109 		;	/* do nothing */
2110 	else if (new_state != USB_STATE_NOTATTACHED) {
2111 
2112 		/* root hub wakeup capabilities are managed out-of-band
2113 		 * and may involve silicon errata ... ignore them here.
2114 		 */
2115 		if (udev->parent) {
2116 			if (udev->state == USB_STATE_SUSPENDED
2117 					|| new_state == USB_STATE_SUSPENDED)
2118 				;	/* No change to wakeup settings */
2119 			else if (new_state == USB_STATE_CONFIGURED)
2120 				wakeup = (udev->quirks &
2121 					USB_QUIRK_IGNORE_REMOTE_WAKEUP) ? 0 :
2122 					udev->actconfig->desc.bmAttributes &
2123 					USB_CONFIG_ATT_WAKEUP;
2124 			else
2125 				wakeup = 0;
2126 		}
2127 		if (udev->state == USB_STATE_SUSPENDED &&
2128 			new_state != USB_STATE_SUSPENDED)
2129 			udev->active_duration -= jiffies;
2130 		else if (new_state == USB_STATE_SUSPENDED &&
2131 				udev->state != USB_STATE_SUSPENDED)
2132 			udev->active_duration += jiffies;
2133 		udev->state = new_state;
2134 		update_port_device_state(udev);
2135 	} else
2136 		recursively_mark_NOTATTACHED(udev);
2137 	spin_unlock_irqrestore(&device_state_lock, flags);
2138 	if (wakeup >= 0)
2139 		device_set_wakeup_capable(&udev->dev, wakeup);
2140 }
2141 EXPORT_SYMBOL_GPL(usb_set_device_state);
2142 
2143 /*
2144  * Choose a device number.
2145  *
2146  * Device numbers are used as filenames in usbfs.  On USB-1.1 and
2147  * USB-2.0 buses they are also used as device addresses, however on
2148  * USB-3.0 buses the address is assigned by the controller hardware
2149  * and it usually is not the same as the device number.
2150  *
2151  * Devices connected under xHCI are not as simple.  The host controller
2152  * supports virtualization, so the hardware assigns device addresses and
2153  * the HCD must setup data structures before issuing a set address
2154  * command to the hardware.
2155  */
choose_devnum(struct usb_device * udev)2156 static void choose_devnum(struct usb_device *udev)
2157 {
2158 	int		devnum;
2159 	struct usb_bus	*bus = udev->bus;
2160 
2161 	/* be safe when more hub events are proceed in parallel */
2162 	mutex_lock(&bus->devnum_next_mutex);
2163 
2164 	/* Try to allocate the next devnum beginning at bus->devnum_next. */
2165 	devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
2166 			bus->devnum_next);
2167 	if (devnum >= 128)
2168 		devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1);
2169 	bus->devnum_next = (devnum >= 127 ? 1 : devnum + 1);
2170 	if (devnum < 128) {
2171 		set_bit(devnum, bus->devmap.devicemap);
2172 		udev->devnum = devnum;
2173 	}
2174 	mutex_unlock(&bus->devnum_next_mutex);
2175 }
2176 
release_devnum(struct usb_device * udev)2177 static void release_devnum(struct usb_device *udev)
2178 {
2179 	if (udev->devnum > 0) {
2180 		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
2181 		udev->devnum = -1;
2182 	}
2183 }
2184 
update_devnum(struct usb_device * udev,int devnum)2185 static void update_devnum(struct usb_device *udev, int devnum)
2186 {
2187 	udev->devnum = devnum;
2188 	if (!udev->devaddr)
2189 		udev->devaddr = (u8)devnum;
2190 }
2191 
hub_free_dev(struct usb_device * udev)2192 static void hub_free_dev(struct usb_device *udev)
2193 {
2194 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2195 
2196 	/* Root hubs aren't real devices, so don't free HCD resources */
2197 	if (hcd->driver->free_dev && udev->parent)
2198 		hcd->driver->free_dev(hcd, udev);
2199 }
2200 
hub_disconnect_children(struct usb_device * udev)2201 static void hub_disconnect_children(struct usb_device *udev)
2202 {
2203 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
2204 	int i;
2205 
2206 	/* Free up all the children before we remove this device */
2207 	for (i = 0; i < udev->maxchild; i++) {
2208 		if (hub->ports[i]->child)
2209 			usb_disconnect(&hub->ports[i]->child);
2210 	}
2211 }
2212 
2213 /**
2214  * usb_disconnect - disconnect a device (usbcore-internal)
2215  * @pdev: pointer to device being disconnected
2216  *
2217  * Context: task context, might sleep
2218  *
2219  * Something got disconnected. Get rid of it and all of its children.
2220  *
2221  * If *pdev is a normal device then the parent hub must already be locked.
2222  * If *pdev is a root hub then the caller must hold the usb_bus_idr_lock,
2223  * which protects the set of root hubs as well as the list of buses.
2224  *
2225  * Only hub drivers (including virtual root hub drivers for host
2226  * controllers) should ever call this.
2227  *
2228  * This call is synchronous, and may not be used in an interrupt context.
2229  */
usb_disconnect(struct usb_device ** pdev)2230 void usb_disconnect(struct usb_device **pdev)
2231 {
2232 	struct usb_port *port_dev = NULL;
2233 	struct usb_device *udev = *pdev;
2234 	struct usb_hub *hub = NULL;
2235 	int port1 = 1;
2236 
2237 	/* mark the device as inactive, so any further urb submissions for
2238 	 * this device (and any of its children) will fail immediately.
2239 	 * this quiesces everything except pending urbs.
2240 	 */
2241 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2242 	dev_info(&udev->dev, "USB disconnect, device number %d\n",
2243 			udev->devnum);
2244 
2245 	/*
2246 	 * Ensure that the pm runtime code knows that the USB device
2247 	 * is in the process of being disconnected.
2248 	 */
2249 	pm_runtime_barrier(&udev->dev);
2250 
2251 	usb_lock_device(udev);
2252 
2253 	hub_disconnect_children(udev);
2254 
2255 	/* deallocate hcd/hardware state ... nuking all pending urbs and
2256 	 * cleaning up all state associated with the current configuration
2257 	 * so that the hardware is now fully quiesced.
2258 	 */
2259 	dev_dbg(&udev->dev, "unregistering device\n");
2260 	usb_disable_device(udev, 0);
2261 	usb_hcd_synchronize_unlinks(udev);
2262 
2263 	if (udev->parent) {
2264 		port1 = udev->portnum;
2265 		hub = usb_hub_to_struct_hub(udev->parent);
2266 		port_dev = hub->ports[port1 - 1];
2267 
2268 		sysfs_remove_link(&udev->dev.kobj, "port");
2269 		sysfs_remove_link(&port_dev->dev.kobj, "device");
2270 
2271 		/*
2272 		 * As usb_port_runtime_resume() de-references udev, make
2273 		 * sure no resumes occur during removal
2274 		 */
2275 		if (!test_and_set_bit(port1, hub->child_usage_bits))
2276 			pm_runtime_get_sync(&port_dev->dev);
2277 	}
2278 
2279 	usb_remove_ep_devs(&udev->ep0);
2280 	usb_unlock_device(udev);
2281 
2282 	/* Unregister the device.  The device driver is responsible
2283 	 * for de-configuring the device and invoking the remove-device
2284 	 * notifier chain (used by usbfs and possibly others).
2285 	 */
2286 	device_del(&udev->dev);
2287 
2288 	/* Free the device number and delete the parent's children[]
2289 	 * (or root_hub) pointer.
2290 	 */
2291 	release_devnum(udev);
2292 
2293 	/* Avoid races with recursively_mark_NOTATTACHED() */
2294 	spin_lock_irq(&device_state_lock);
2295 	*pdev = NULL;
2296 	spin_unlock_irq(&device_state_lock);
2297 
2298 	if (port_dev && test_and_clear_bit(port1, hub->child_usage_bits))
2299 		pm_runtime_put(&port_dev->dev);
2300 
2301 	hub_free_dev(udev);
2302 
2303 	put_device(&udev->dev);
2304 }
2305 
2306 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
show_string(struct usb_device * udev,char * id,char * string)2307 static void show_string(struct usb_device *udev, char *id, char *string)
2308 {
2309 	if (!string)
2310 		return;
2311 	dev_info(&udev->dev, "%s: %s\n", id, string);
2312 }
2313 
announce_device(struct usb_device * udev)2314 static void announce_device(struct usb_device *udev)
2315 {
2316 	u16 bcdDevice = le16_to_cpu(udev->descriptor.bcdDevice);
2317 
2318 	dev_info(&udev->dev,
2319 		"New USB device found, idVendor=%04x, idProduct=%04x, bcdDevice=%2x.%02x\n",
2320 		le16_to_cpu(udev->descriptor.idVendor),
2321 		le16_to_cpu(udev->descriptor.idProduct),
2322 		bcdDevice >> 8, bcdDevice & 0xff);
2323 	dev_info(&udev->dev,
2324 		"New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
2325 		udev->descriptor.iManufacturer,
2326 		udev->descriptor.iProduct,
2327 		udev->descriptor.iSerialNumber);
2328 	show_string(udev, "Product", udev->product);
2329 	show_string(udev, "Manufacturer", udev->manufacturer);
2330 	show_string(udev, "SerialNumber", udev->serial);
2331 }
2332 #else
announce_device(struct usb_device * udev)2333 static inline void announce_device(struct usb_device *udev) { }
2334 #endif
2335 
2336 
2337 /**
2338  * usb_enumerate_device_otg - FIXME (usbcore-internal)
2339  * @udev: newly addressed device (in ADDRESS state)
2340  *
2341  * Finish enumeration for On-The-Go devices
2342  *
2343  * Return: 0 if successful. A negative error code otherwise.
2344  */
usb_enumerate_device_otg(struct usb_device * udev)2345 static int usb_enumerate_device_otg(struct usb_device *udev)
2346 {
2347 	int err = 0;
2348 
2349 #ifdef	CONFIG_USB_OTG
2350 	/*
2351 	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
2352 	 * to wake us after we've powered off VBUS; and HNP, switching roles
2353 	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
2354 	 */
2355 	if (!udev->bus->is_b_host
2356 			&& udev->config
2357 			&& udev->parent == udev->bus->root_hub) {
2358 		struct usb_otg_descriptor	*desc = NULL;
2359 		struct usb_bus			*bus = udev->bus;
2360 		unsigned			port1 = udev->portnum;
2361 
2362 		/* descriptor may appear anywhere in config */
2363 		err = __usb_get_extra_descriptor(udev->rawdescriptors[0],
2364 				le16_to_cpu(udev->config[0].desc.wTotalLength),
2365 				USB_DT_OTG, (void **) &desc, sizeof(*desc));
2366 		if (err || !(desc->bmAttributes & USB_OTG_HNP))
2367 			return 0;
2368 
2369 		dev_info(&udev->dev, "Dual-Role OTG device on %sHNP port\n",
2370 					(port1 == bus->otg_port) ? "" : "non-");
2371 
2372 		/* enable HNP before suspend, it's simpler */
2373 		if (port1 == bus->otg_port) {
2374 			bus->b_hnp_enable = 1;
2375 			err = usb_control_msg(udev,
2376 				usb_sndctrlpipe(udev, 0),
2377 				USB_REQ_SET_FEATURE, 0,
2378 				USB_DEVICE_B_HNP_ENABLE,
2379 				0, NULL, 0,
2380 				USB_CTRL_SET_TIMEOUT);
2381 			if (err < 0) {
2382 				/*
2383 				 * OTG MESSAGE: report errors here,
2384 				 * customize to match your product.
2385 				 */
2386 				dev_err(&udev->dev, "can't set HNP mode: %d\n",
2387 									err);
2388 				bus->b_hnp_enable = 0;
2389 			}
2390 		} else if (desc->bLength == sizeof
2391 				(struct usb_otg_descriptor)) {
2392 			/* Set a_alt_hnp_support for legacy otg device */
2393 			err = usb_control_msg(udev,
2394 				usb_sndctrlpipe(udev, 0),
2395 				USB_REQ_SET_FEATURE, 0,
2396 				USB_DEVICE_A_ALT_HNP_SUPPORT,
2397 				0, NULL, 0,
2398 				USB_CTRL_SET_TIMEOUT);
2399 			if (err < 0)
2400 				dev_err(&udev->dev,
2401 					"set a_alt_hnp_support failed: %d\n",
2402 					err);
2403 		}
2404 	}
2405 #endif
2406 	return err;
2407 }
2408 
2409 
2410 /**
2411  * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal)
2412  * @udev: newly addressed device (in ADDRESS state)
2413  *
2414  * This is only called by usb_new_device() -- all comments that apply there
2415  * apply here wrt to environment.
2416  *
2417  * If the device is WUSB and not authorized, we don't attempt to read
2418  * the string descriptors, as they will be errored out by the device
2419  * until it has been authorized.
2420  *
2421  * Return: 0 if successful. A negative error code otherwise.
2422  */
usb_enumerate_device(struct usb_device * udev)2423 static int usb_enumerate_device(struct usb_device *udev)
2424 {
2425 	int err;
2426 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2427 
2428 	if (udev->config == NULL) {
2429 		err = usb_get_configuration(udev);
2430 		if (err < 0) {
2431 			if (err != -ENODEV)
2432 				dev_err(&udev->dev, "can't read configurations, error %d\n",
2433 						err);
2434 			return err;
2435 		}
2436 	}
2437 
2438 	/* read the standard strings and cache them if present */
2439 	udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
2440 	udev->manufacturer = usb_cache_string(udev,
2441 					      udev->descriptor.iManufacturer);
2442 	udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
2443 
2444 	err = usb_enumerate_device_otg(udev);
2445 	if (err < 0)
2446 		return err;
2447 
2448 	if (IS_ENABLED(CONFIG_USB_OTG_PRODUCTLIST) && hcd->tpl_support &&
2449 		!is_targeted(udev)) {
2450 		/* Maybe it can talk to us, though we can't talk to it.
2451 		 * (Includes HNP test device.)
2452 		 */
2453 		if (IS_ENABLED(CONFIG_USB_OTG) && (udev->bus->b_hnp_enable
2454 			|| udev->bus->is_b_host)) {
2455 			err = usb_port_suspend(udev, PMSG_AUTO_SUSPEND);
2456 			if (err < 0)
2457 				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
2458 		}
2459 		return -ENOTSUPP;
2460 	}
2461 
2462 	usb_detect_interface_quirks(udev);
2463 
2464 	return 0;
2465 }
2466 
set_usb_port_removable(struct usb_device * udev)2467 static void set_usb_port_removable(struct usb_device *udev)
2468 {
2469 	struct usb_device *hdev = udev->parent;
2470 	struct usb_hub *hub;
2471 	u8 port = udev->portnum;
2472 	u16 wHubCharacteristics;
2473 	bool removable = true;
2474 
2475 	dev_set_removable(&udev->dev, DEVICE_REMOVABLE_UNKNOWN);
2476 
2477 	if (!hdev)
2478 		return;
2479 
2480 	hub = usb_hub_to_struct_hub(udev->parent);
2481 
2482 	/*
2483 	 * If the platform firmware has provided information about a port,
2484 	 * use that to determine whether it's removable.
2485 	 */
2486 	switch (hub->ports[udev->portnum - 1]->connect_type) {
2487 	case USB_PORT_CONNECT_TYPE_HOT_PLUG:
2488 		dev_set_removable(&udev->dev, DEVICE_REMOVABLE);
2489 		return;
2490 	case USB_PORT_CONNECT_TYPE_HARD_WIRED:
2491 	case USB_PORT_NOT_USED:
2492 		dev_set_removable(&udev->dev, DEVICE_FIXED);
2493 		return;
2494 	default:
2495 		break;
2496 	}
2497 
2498 	/*
2499 	 * Otherwise, check whether the hub knows whether a port is removable
2500 	 * or not
2501 	 */
2502 	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2503 
2504 	if (!(wHubCharacteristics & HUB_CHAR_COMPOUND))
2505 		return;
2506 
2507 	if (hub_is_superspeed(hdev)) {
2508 		if (le16_to_cpu(hub->descriptor->u.ss.DeviceRemovable)
2509 				& (1 << port))
2510 			removable = false;
2511 	} else {
2512 		if (hub->descriptor->u.hs.DeviceRemovable[port / 8] & (1 << (port % 8)))
2513 			removable = false;
2514 	}
2515 
2516 	if (removable)
2517 		dev_set_removable(&udev->dev, DEVICE_REMOVABLE);
2518 	else
2519 		dev_set_removable(&udev->dev, DEVICE_FIXED);
2520 
2521 }
2522 
2523 /**
2524  * usb_new_device - perform initial device setup (usbcore-internal)
2525  * @udev: newly addressed device (in ADDRESS state)
2526  *
2527  * This is called with devices which have been detected but not fully
2528  * enumerated.  The device descriptor is available, but not descriptors
2529  * for any device configuration.  The caller must have locked either
2530  * the parent hub (if udev is a normal device) or else the
2531  * usb_bus_idr_lock (if udev is a root hub).  The parent's pointer to
2532  * udev has already been installed, but udev is not yet visible through
2533  * sysfs or other filesystem code.
2534  *
2535  * This call is synchronous, and may not be used in an interrupt context.
2536  *
2537  * Only the hub driver or root-hub registrar should ever call this.
2538  *
2539  * Return: Whether the device is configured properly or not. Zero if the
2540  * interface was registered with the driver core; else a negative errno
2541  * value.
2542  *
2543  */
usb_new_device(struct usb_device * udev)2544 int usb_new_device(struct usb_device *udev)
2545 {
2546 	int err;
2547 
2548 	if (udev->parent) {
2549 		/* Initialize non-root-hub device wakeup to disabled;
2550 		 * device (un)configuration controls wakeup capable
2551 		 * sysfs power/wakeup controls wakeup enabled/disabled
2552 		 */
2553 		device_init_wakeup(&udev->dev, 0);
2554 	}
2555 
2556 	/* Tell the runtime-PM framework the device is active */
2557 	pm_runtime_set_active(&udev->dev);
2558 	pm_runtime_get_noresume(&udev->dev);
2559 	pm_runtime_use_autosuspend(&udev->dev);
2560 	pm_runtime_enable(&udev->dev);
2561 
2562 	/* By default, forbid autosuspend for all devices.  It will be
2563 	 * allowed for hubs during binding.
2564 	 */
2565 	usb_disable_autosuspend(udev);
2566 
2567 	err = usb_enumerate_device(udev);	/* Read descriptors */
2568 	if (err < 0)
2569 		goto fail;
2570 	dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n",
2571 			udev->devnum, udev->bus->busnum,
2572 			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2573 	/* export the usbdev device-node for libusb */
2574 	udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
2575 			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2576 
2577 	/* Tell the world! */
2578 	announce_device(udev);
2579 
2580 	if (udev->serial)
2581 		add_device_randomness(udev->serial, strlen(udev->serial));
2582 	if (udev->product)
2583 		add_device_randomness(udev->product, strlen(udev->product));
2584 	if (udev->manufacturer)
2585 		add_device_randomness(udev->manufacturer,
2586 				      strlen(udev->manufacturer));
2587 
2588 	device_enable_async_suspend(&udev->dev);
2589 
2590 	/* check whether the hub or firmware marks this port as non-removable */
2591 	set_usb_port_removable(udev);
2592 
2593 	/* Register the device.  The device driver is responsible
2594 	 * for configuring the device and invoking the add-device
2595 	 * notifier chain (used by usbfs and possibly others).
2596 	 */
2597 	err = device_add(&udev->dev);
2598 	if (err) {
2599 		dev_err(&udev->dev, "can't device_add, error %d\n", err);
2600 		goto fail;
2601 	}
2602 
2603 	/* Create link files between child device and usb port device. */
2604 	if (udev->parent) {
2605 		struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
2606 		int port1 = udev->portnum;
2607 		struct usb_port	*port_dev = hub->ports[port1 - 1];
2608 
2609 		err = sysfs_create_link(&udev->dev.kobj,
2610 				&port_dev->dev.kobj, "port");
2611 		if (err)
2612 			goto fail;
2613 
2614 		err = sysfs_create_link(&port_dev->dev.kobj,
2615 				&udev->dev.kobj, "device");
2616 		if (err) {
2617 			sysfs_remove_link(&udev->dev.kobj, "port");
2618 			goto fail;
2619 		}
2620 
2621 		if (!test_and_set_bit(port1, hub->child_usage_bits))
2622 			pm_runtime_get_sync(&port_dev->dev);
2623 	}
2624 
2625 	(void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
2626 	usb_mark_last_busy(udev);
2627 	pm_runtime_put_sync_autosuspend(&udev->dev);
2628 	return err;
2629 
2630 fail:
2631 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2632 	pm_runtime_disable(&udev->dev);
2633 	pm_runtime_set_suspended(&udev->dev);
2634 	return err;
2635 }
2636 
2637 
2638 /**
2639  * usb_deauthorize_device - deauthorize a device (usbcore-internal)
2640  * @usb_dev: USB device
2641  *
2642  * Move the USB device to a very basic state where interfaces are disabled
2643  * and the device is in fact unconfigured and unusable.
2644  *
2645  * We share a lock (that we have) with device_del(), so we need to
2646  * defer its call.
2647  *
2648  * Return: 0.
2649  */
usb_deauthorize_device(struct usb_device * usb_dev)2650 int usb_deauthorize_device(struct usb_device *usb_dev)
2651 {
2652 	usb_lock_device(usb_dev);
2653 	if (usb_dev->authorized == 0)
2654 		goto out_unauthorized;
2655 
2656 	usb_dev->authorized = 0;
2657 	usb_set_configuration(usb_dev, -1);
2658 
2659 out_unauthorized:
2660 	usb_unlock_device(usb_dev);
2661 	return 0;
2662 }
2663 
2664 
usb_authorize_device(struct usb_device * usb_dev)2665 int usb_authorize_device(struct usb_device *usb_dev)
2666 {
2667 	int result = 0, c;
2668 
2669 	usb_lock_device(usb_dev);
2670 	if (usb_dev->authorized == 1)
2671 		goto out_authorized;
2672 
2673 	result = usb_autoresume_device(usb_dev);
2674 	if (result < 0) {
2675 		dev_err(&usb_dev->dev,
2676 			"can't autoresume for authorization: %d\n", result);
2677 		goto error_autoresume;
2678 	}
2679 
2680 	usb_dev->authorized = 1;
2681 	/* Choose and set the configuration.  This registers the interfaces
2682 	 * with the driver core and lets interface drivers bind to them.
2683 	 */
2684 	c = usb_choose_configuration(usb_dev);
2685 	if (c >= 0) {
2686 		result = usb_set_configuration(usb_dev, c);
2687 		if (result) {
2688 			dev_err(&usb_dev->dev,
2689 				"can't set config #%d, error %d\n", c, result);
2690 			/* This need not be fatal.  The user can try to
2691 			 * set other configurations. */
2692 		}
2693 	}
2694 	dev_info(&usb_dev->dev, "authorized to connect\n");
2695 
2696 	usb_autosuspend_device(usb_dev);
2697 error_autoresume:
2698 out_authorized:
2699 	usb_unlock_device(usb_dev);	/* complements locktree */
2700 	return result;
2701 }
2702 
2703 /**
2704  * get_port_ssp_rate - Match the extended port status to SSP rate
2705  * @hdev: The hub device
2706  * @ext_portstatus: extended port status
2707  *
2708  * Match the extended port status speed id to the SuperSpeed Plus sublink speed
2709  * capability attributes. Base on the number of connected lanes and speed,
2710  * return the corresponding enum usb_ssp_rate.
2711  */
get_port_ssp_rate(struct usb_device * hdev,u32 ext_portstatus)2712 static enum usb_ssp_rate get_port_ssp_rate(struct usb_device *hdev,
2713 					   u32 ext_portstatus)
2714 {
2715 	struct usb_ssp_cap_descriptor *ssp_cap;
2716 	u32 attr;
2717 	u8 speed_id;
2718 	u8 ssac;
2719 	u8 lanes;
2720 	int i;
2721 
2722 	if (!hdev->bos)
2723 		goto out;
2724 
2725 	ssp_cap = hdev->bos->ssp_cap;
2726 	if (!ssp_cap)
2727 		goto out;
2728 
2729 	speed_id = ext_portstatus & USB_EXT_PORT_STAT_RX_SPEED_ID;
2730 	lanes = USB_EXT_PORT_RX_LANES(ext_portstatus) + 1;
2731 
2732 	ssac = le32_to_cpu(ssp_cap->bmAttributes) &
2733 		USB_SSP_SUBLINK_SPEED_ATTRIBS;
2734 
2735 	for (i = 0; i <= ssac; i++) {
2736 		u8 ssid;
2737 
2738 		attr = le32_to_cpu(ssp_cap->bmSublinkSpeedAttr[i]);
2739 		ssid = FIELD_GET(USB_SSP_SUBLINK_SPEED_SSID, attr);
2740 		if (speed_id == ssid) {
2741 			u16 mantissa;
2742 			u8 lse;
2743 			u8 type;
2744 
2745 			/*
2746 			 * Note: currently asymmetric lane types are only
2747 			 * applicable for SSIC operate in SuperSpeed protocol
2748 			 */
2749 			type = FIELD_GET(USB_SSP_SUBLINK_SPEED_ST, attr);
2750 			if (type == USB_SSP_SUBLINK_SPEED_ST_ASYM_RX ||
2751 			    type == USB_SSP_SUBLINK_SPEED_ST_ASYM_TX)
2752 				goto out;
2753 
2754 			if (FIELD_GET(USB_SSP_SUBLINK_SPEED_LP, attr) !=
2755 			    USB_SSP_SUBLINK_SPEED_LP_SSP)
2756 				goto out;
2757 
2758 			lse = FIELD_GET(USB_SSP_SUBLINK_SPEED_LSE, attr);
2759 			mantissa = FIELD_GET(USB_SSP_SUBLINK_SPEED_LSM, attr);
2760 
2761 			/* Convert to Gbps */
2762 			for (; lse < USB_SSP_SUBLINK_SPEED_LSE_GBPS; lse++)
2763 				mantissa /= 1000;
2764 
2765 			if (mantissa >= 10 && lanes == 1)
2766 				return USB_SSP_GEN_2x1;
2767 
2768 			if (mantissa >= 10 && lanes == 2)
2769 				return USB_SSP_GEN_2x2;
2770 
2771 			if (mantissa >= 5 && lanes == 2)
2772 				return USB_SSP_GEN_1x2;
2773 
2774 			goto out;
2775 		}
2776 	}
2777 
2778 out:
2779 	return USB_SSP_GEN_UNKNOWN;
2780 }
2781 
2782 #ifdef CONFIG_USB_FEW_INIT_RETRIES
2783 #define PORT_RESET_TRIES	2
2784 #define SET_ADDRESS_TRIES	1
2785 #define GET_DESCRIPTOR_TRIES	1
2786 #define GET_MAXPACKET0_TRIES	1
2787 #define PORT_INIT_TRIES		4
2788 
2789 #else
2790 #define PORT_RESET_TRIES	5
2791 #define SET_ADDRESS_TRIES	2
2792 #define GET_DESCRIPTOR_TRIES	2
2793 #define GET_MAXPACKET0_TRIES	3
2794 #define PORT_INIT_TRIES		4
2795 #endif	/* CONFIG_USB_FEW_INIT_RETRIES */
2796 
2797 #define DETECT_DISCONNECT_TRIES 5
2798 
2799 #define HUB_ROOT_RESET_TIME	60	/* times are in msec */
2800 #define HUB_SHORT_RESET_TIME	10
2801 #define HUB_BH_RESET_TIME	50
2802 #define HUB_LONG_RESET_TIME	200
2803 #define HUB_RESET_TIMEOUT	800
2804 
use_new_scheme(struct usb_device * udev,int retry,struct usb_port * port_dev)2805 static bool use_new_scheme(struct usb_device *udev, int retry,
2806 			   struct usb_port *port_dev)
2807 {
2808 	int old_scheme_first_port =
2809 		(port_dev->quirks & USB_PORT_QUIRK_OLD_SCHEME) ||
2810 		old_scheme_first;
2811 
2812 	/*
2813 	 * "New scheme" enumeration causes an extra state transition to be
2814 	 * exposed to an xhci host and causes USB3 devices to receive control
2815 	 * commands in the default state.  This has been seen to cause
2816 	 * enumeration failures, so disable this enumeration scheme for USB3
2817 	 * devices.
2818 	 */
2819 	if (udev->speed >= USB_SPEED_SUPER)
2820 		return false;
2821 
2822 	/*
2823 	 * If use_both_schemes is set, use the first scheme (whichever
2824 	 * it is) for the larger half of the retries, then use the other
2825 	 * scheme.  Otherwise, use the first scheme for all the retries.
2826 	 */
2827 	if (use_both_schemes && retry >= (PORT_INIT_TRIES + 1) / 2)
2828 		return old_scheme_first_port;	/* Second half */
2829 	return !old_scheme_first_port;		/* First half or all */
2830 }
2831 
2832 /* Is a USB 3.0 port in the Inactive or Compliance Mode state?
2833  * Port warm reset is required to recover
2834  */
hub_port_warm_reset_required(struct usb_hub * hub,int port1,u16 portstatus)2835 static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1,
2836 		u16 portstatus)
2837 {
2838 	u16 link_state;
2839 
2840 	if (!hub_is_superspeed(hub->hdev))
2841 		return false;
2842 
2843 	if (test_bit(port1, hub->warm_reset_bits))
2844 		return true;
2845 
2846 	link_state = portstatus & USB_PORT_STAT_LINK_STATE;
2847 	return link_state == USB_SS_PORT_LS_SS_INACTIVE
2848 		|| link_state == USB_SS_PORT_LS_COMP_MOD;
2849 }
2850 
hub_port_wait_reset(struct usb_hub * hub,int port1,struct usb_device * udev,unsigned int delay,bool warm)2851 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
2852 			struct usb_device *udev, unsigned int delay, bool warm)
2853 {
2854 	int delay_time, ret;
2855 	u16 portstatus;
2856 	u16 portchange;
2857 	u32 ext_portstatus = 0;
2858 
2859 	for (delay_time = 0;
2860 			delay_time < HUB_RESET_TIMEOUT;
2861 			delay_time += delay) {
2862 		/* wait to give the device a chance to reset */
2863 		msleep(delay);
2864 
2865 		/* read and decode port status */
2866 		if (hub_is_superspeedplus(hub->hdev))
2867 			ret = hub_ext_port_status(hub, port1,
2868 						  HUB_EXT_PORT_STATUS,
2869 						  &portstatus, &portchange,
2870 						  &ext_portstatus);
2871 		else
2872 			ret = usb_hub_port_status(hub, port1, &portstatus,
2873 					      &portchange);
2874 		if (ret < 0)
2875 			return ret;
2876 
2877 		/*
2878 		 * The port state is unknown until the reset completes.
2879 		 *
2880 		 * On top of that, some chips may require additional time
2881 		 * to re-establish a connection after the reset is complete,
2882 		 * so also wait for the connection to be re-established.
2883 		 */
2884 		if (!(portstatus & USB_PORT_STAT_RESET) &&
2885 		    (portstatus & USB_PORT_STAT_CONNECTION))
2886 			break;
2887 
2888 		/* switch to the long delay after two short delay failures */
2889 		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
2890 			delay = HUB_LONG_RESET_TIME;
2891 
2892 		dev_dbg(&hub->ports[port1 - 1]->dev,
2893 				"not %sreset yet, waiting %dms\n",
2894 				warm ? "warm " : "", delay);
2895 	}
2896 
2897 	if ((portstatus & USB_PORT_STAT_RESET))
2898 		return -EBUSY;
2899 
2900 	if (hub_port_warm_reset_required(hub, port1, portstatus))
2901 		return -ENOTCONN;
2902 
2903 	/* Device went away? */
2904 	if (!(portstatus & USB_PORT_STAT_CONNECTION))
2905 		return -ENOTCONN;
2906 
2907 	/* Retry if connect change is set but status is still connected.
2908 	 * A USB 3.0 connection may bounce if multiple warm resets were issued,
2909 	 * but the device may have successfully re-connected. Ignore it.
2910 	 */
2911 	if (!hub_is_superspeed(hub->hdev) &&
2912 	    (portchange & USB_PORT_STAT_C_CONNECTION)) {
2913 		usb_clear_port_feature(hub->hdev, port1,
2914 				       USB_PORT_FEAT_C_CONNECTION);
2915 		return -EAGAIN;
2916 	}
2917 
2918 	if (!(portstatus & USB_PORT_STAT_ENABLE))
2919 		return -EBUSY;
2920 
2921 	if (!udev)
2922 		return 0;
2923 
2924 	if (hub_is_superspeedplus(hub->hdev)) {
2925 		/* extended portstatus Rx and Tx lane count are zero based */
2926 		udev->rx_lanes = USB_EXT_PORT_RX_LANES(ext_portstatus) + 1;
2927 		udev->tx_lanes = USB_EXT_PORT_TX_LANES(ext_portstatus) + 1;
2928 		udev->ssp_rate = get_port_ssp_rate(hub->hdev, ext_portstatus);
2929 	} else {
2930 		udev->rx_lanes = 1;
2931 		udev->tx_lanes = 1;
2932 		udev->ssp_rate = USB_SSP_GEN_UNKNOWN;
2933 	}
2934 	if (udev->ssp_rate != USB_SSP_GEN_UNKNOWN)
2935 		udev->speed = USB_SPEED_SUPER_PLUS;
2936 	else if (hub_is_superspeed(hub->hdev))
2937 		udev->speed = USB_SPEED_SUPER;
2938 	else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
2939 		udev->speed = USB_SPEED_HIGH;
2940 	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
2941 		udev->speed = USB_SPEED_LOW;
2942 	else
2943 		udev->speed = USB_SPEED_FULL;
2944 	return 0;
2945 }
2946 
2947 /* Handle port reset and port warm(BH) reset (for USB3 protocol ports) */
hub_port_reset(struct usb_hub * hub,int port1,struct usb_device * udev,unsigned int delay,bool warm)2948 static int hub_port_reset(struct usb_hub *hub, int port1,
2949 			struct usb_device *udev, unsigned int delay, bool warm)
2950 {
2951 	int i, status;
2952 	u16 portchange, portstatus;
2953 	struct usb_port *port_dev = hub->ports[port1 - 1];
2954 	int reset_recovery_time;
2955 
2956 	if (!hub_is_superspeed(hub->hdev)) {
2957 		if (warm) {
2958 			dev_err(hub->intfdev, "only USB3 hub support "
2959 						"warm reset\n");
2960 			return -EINVAL;
2961 		}
2962 		/* Block EHCI CF initialization during the port reset.
2963 		 * Some companion controllers don't like it when they mix.
2964 		 */
2965 		down_read(&ehci_cf_port_reset_rwsem);
2966 	} else if (!warm) {
2967 		/*
2968 		 * If the caller hasn't explicitly requested a warm reset,
2969 		 * double check and see if one is needed.
2970 		 */
2971 		if (usb_hub_port_status(hub, port1, &portstatus,
2972 					&portchange) == 0)
2973 			if (hub_port_warm_reset_required(hub, port1,
2974 							portstatus))
2975 				warm = true;
2976 	}
2977 	clear_bit(port1, hub->warm_reset_bits);
2978 
2979 	/* Reset the port */
2980 	for (i = 0; i < PORT_RESET_TRIES; i++) {
2981 		status = set_port_feature(hub->hdev, port1, (warm ?
2982 					USB_PORT_FEAT_BH_PORT_RESET :
2983 					USB_PORT_FEAT_RESET));
2984 		if (status == -ENODEV) {
2985 			;	/* The hub is gone */
2986 		} else if (status) {
2987 			dev_err(&port_dev->dev,
2988 					"cannot %sreset (err = %d)\n",
2989 					warm ? "warm " : "", status);
2990 		} else {
2991 			status = hub_port_wait_reset(hub, port1, udev, delay,
2992 								warm);
2993 			if (status && status != -ENOTCONN && status != -ENODEV)
2994 				dev_dbg(hub->intfdev,
2995 						"port_wait_reset: err = %d\n",
2996 						status);
2997 		}
2998 
2999 		/*
3000 		 * Check for disconnect or reset, and bail out after several
3001 		 * reset attempts to avoid warm reset loop.
3002 		 */
3003 		if (status == 0 || status == -ENOTCONN || status == -ENODEV ||
3004 		    (status == -EBUSY && i == PORT_RESET_TRIES - 1)) {
3005 			usb_clear_port_feature(hub->hdev, port1,
3006 					USB_PORT_FEAT_C_RESET);
3007 
3008 			if (!hub_is_superspeed(hub->hdev))
3009 				goto done;
3010 
3011 			usb_clear_port_feature(hub->hdev, port1,
3012 					USB_PORT_FEAT_C_BH_PORT_RESET);
3013 			usb_clear_port_feature(hub->hdev, port1,
3014 					USB_PORT_FEAT_C_PORT_LINK_STATE);
3015 
3016 			if (udev)
3017 				usb_clear_port_feature(hub->hdev, port1,
3018 					USB_PORT_FEAT_C_CONNECTION);
3019 
3020 			/*
3021 			 * If a USB 3.0 device migrates from reset to an error
3022 			 * state, re-issue the warm reset.
3023 			 */
3024 			if (usb_hub_port_status(hub, port1,
3025 					&portstatus, &portchange) < 0)
3026 				goto done;
3027 
3028 			if (!hub_port_warm_reset_required(hub, port1,
3029 					portstatus))
3030 				goto done;
3031 
3032 			/*
3033 			 * If the port is in SS.Inactive or Compliance Mode, the
3034 			 * hot or warm reset failed.  Try another warm reset.
3035 			 */
3036 			if (!warm) {
3037 				dev_dbg(&port_dev->dev,
3038 						"hot reset failed, warm reset\n");
3039 				warm = true;
3040 			}
3041 		}
3042 
3043 		dev_dbg(&port_dev->dev,
3044 				"not enabled, trying %sreset again...\n",
3045 				warm ? "warm " : "");
3046 		delay = HUB_LONG_RESET_TIME;
3047 	}
3048 
3049 	dev_err(&port_dev->dev, "Cannot enable. Maybe the USB cable is bad?\n");
3050 
3051 done:
3052 	if (status == 0) {
3053 		if (port_dev->quirks & USB_PORT_QUIRK_FAST_ENUM)
3054 			usleep_range(10000, 12000);
3055 		else {
3056 			/* TRSTRCY = 10 ms; plus some extra */
3057 			reset_recovery_time = 10 + 40;
3058 
3059 			/* Hub needs extra delay after resetting its port. */
3060 			if (hub->hdev->quirks & USB_QUIRK_HUB_SLOW_RESET)
3061 				reset_recovery_time += 100;
3062 
3063 			msleep(reset_recovery_time);
3064 		}
3065 
3066 		if (udev) {
3067 			struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3068 
3069 			update_devnum(udev, 0);
3070 			/* The xHC may think the device is already reset,
3071 			 * so ignore the status.
3072 			 */
3073 			if (hcd->driver->reset_device)
3074 				hcd->driver->reset_device(hcd, udev);
3075 
3076 			usb_set_device_state(udev, USB_STATE_DEFAULT);
3077 		}
3078 	} else {
3079 		if (udev)
3080 			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
3081 	}
3082 
3083 	if (!hub_is_superspeed(hub->hdev))
3084 		up_read(&ehci_cf_port_reset_rwsem);
3085 
3086 	return status;
3087 }
3088 
3089 /*
3090  * hub_port_stop_enumerate - stop USB enumeration or ignore port events
3091  * @hub: target hub
3092  * @port1: port num of the port
3093  * @retries: port retries number of hub_port_init()
3094  *
3095  * Return:
3096  *    true: ignore port actions/events or give up connection attempts.
3097  *    false: keep original behavior.
3098  *
3099  * This function will be based on retries to check whether the port which is
3100  * marked with early_stop attribute would stop enumeration or ignore events.
3101  *
3102  * Note:
3103  * This function didn't change anything if early_stop is not set, and it will
3104  * prevent all connection attempts when early_stop is set and the attempts of
3105  * the port are more than 1.
3106  */
hub_port_stop_enumerate(struct usb_hub * hub,int port1,int retries)3107 static bool hub_port_stop_enumerate(struct usb_hub *hub, int port1, int retries)
3108 {
3109 	struct usb_port *port_dev = hub->ports[port1 - 1];
3110 
3111 	if (port_dev->early_stop) {
3112 		if (port_dev->ignore_event)
3113 			return true;
3114 
3115 		/*
3116 		 * We want unsuccessful attempts to fail quickly.
3117 		 * Since some devices may need one failure during
3118 		 * port initialization, we allow two tries but no
3119 		 * more.
3120 		 */
3121 		if (retries < 2)
3122 			return false;
3123 
3124 		port_dev->ignore_event = 1;
3125 	} else
3126 		port_dev->ignore_event = 0;
3127 
3128 	return port_dev->ignore_event;
3129 }
3130 
3131 /* Check if a port is power on */
usb_port_is_power_on(struct usb_hub * hub,unsigned int portstatus)3132 int usb_port_is_power_on(struct usb_hub *hub, unsigned int portstatus)
3133 {
3134 	int ret = 0;
3135 
3136 	if (hub_is_superspeed(hub->hdev)) {
3137 		if (portstatus & USB_SS_PORT_STAT_POWER)
3138 			ret = 1;
3139 	} else {
3140 		if (portstatus & USB_PORT_STAT_POWER)
3141 			ret = 1;
3142 	}
3143 
3144 	return ret;
3145 }
3146 
usb_lock_port(struct usb_port * port_dev)3147 static void usb_lock_port(struct usb_port *port_dev)
3148 		__acquires(&port_dev->status_lock)
3149 {
3150 	mutex_lock(&port_dev->status_lock);
3151 	__acquire(&port_dev->status_lock);
3152 }
3153 
usb_unlock_port(struct usb_port * port_dev)3154 static void usb_unlock_port(struct usb_port *port_dev)
3155 		__releases(&port_dev->status_lock)
3156 {
3157 	mutex_unlock(&port_dev->status_lock);
3158 	__release(&port_dev->status_lock);
3159 }
3160 
3161 #ifdef	CONFIG_PM
3162 
3163 /* Check if a port is suspended(USB2.0 port) or in U3 state(USB3.0 port) */
port_is_suspended(struct usb_hub * hub,unsigned portstatus)3164 static int port_is_suspended(struct usb_hub *hub, unsigned portstatus)
3165 {
3166 	int ret = 0;
3167 
3168 	if (hub_is_superspeed(hub->hdev)) {
3169 		if ((portstatus & USB_PORT_STAT_LINK_STATE)
3170 				== USB_SS_PORT_LS_U3)
3171 			ret = 1;
3172 	} else {
3173 		if (portstatus & USB_PORT_STAT_SUSPEND)
3174 			ret = 1;
3175 	}
3176 
3177 	return ret;
3178 }
3179 
3180 /* Determine whether the device on a port is ready for a normal resume,
3181  * is ready for a reset-resume, or should be disconnected.
3182  */
check_port_resume_type(struct usb_device * udev,struct usb_hub * hub,int port1,int status,u16 portchange,u16 portstatus)3183 static int check_port_resume_type(struct usb_device *udev,
3184 		struct usb_hub *hub, int port1,
3185 		int status, u16 portchange, u16 portstatus)
3186 {
3187 	struct usb_port *port_dev = hub->ports[port1 - 1];
3188 	int retries = 3;
3189 
3190  retry:
3191 	/* Is a warm reset needed to recover the connection? */
3192 	if (status == 0 && udev->reset_resume
3193 		&& hub_port_warm_reset_required(hub, port1, portstatus)) {
3194 		/* pass */;
3195 	}
3196 	/* Is the device still present? */
3197 	else if (status || port_is_suspended(hub, portstatus) ||
3198 			!usb_port_is_power_on(hub, portstatus)) {
3199 		if (status >= 0)
3200 			status = -ENODEV;
3201 	} else if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
3202 		if (retries--) {
3203 			usleep_range(200, 300);
3204 			status = usb_hub_port_status(hub, port1, &portstatus,
3205 							     &portchange);
3206 			goto retry;
3207 		}
3208 		status = -ENODEV;
3209 	}
3210 
3211 	/* Can't do a normal resume if the port isn't enabled,
3212 	 * so try a reset-resume instead.
3213 	 */
3214 	else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
3215 		if (udev->persist_enabled)
3216 			udev->reset_resume = 1;
3217 		else
3218 			status = -ENODEV;
3219 	}
3220 
3221 	if (status) {
3222 		dev_dbg(&port_dev->dev, "status %04x.%04x after resume, %d\n",
3223 				portchange, portstatus, status);
3224 	} else if (udev->reset_resume) {
3225 
3226 		/* Late port handoff can set status-change bits */
3227 		if (portchange & USB_PORT_STAT_C_CONNECTION)
3228 			usb_clear_port_feature(hub->hdev, port1,
3229 					USB_PORT_FEAT_C_CONNECTION);
3230 		if (portchange & USB_PORT_STAT_C_ENABLE)
3231 			usb_clear_port_feature(hub->hdev, port1,
3232 					USB_PORT_FEAT_C_ENABLE);
3233 
3234 		/*
3235 		 * Whatever made this reset-resume necessary may have
3236 		 * turned on the port1 bit in hub->change_bits.  But after
3237 		 * a successful reset-resume we want the bit to be clear;
3238 		 * if it was on it would indicate that something happened
3239 		 * following the reset-resume.
3240 		 */
3241 		clear_bit(port1, hub->change_bits);
3242 	}
3243 
3244 	return status;
3245 }
3246 
usb_disable_ltm(struct usb_device * udev)3247 int usb_disable_ltm(struct usb_device *udev)
3248 {
3249 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3250 
3251 	/* Check if the roothub and device supports LTM. */
3252 	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
3253 			!usb_device_supports_ltm(udev))
3254 		return 0;
3255 
3256 	/* Clear Feature LTM Enable can only be sent if the device is
3257 	 * configured.
3258 	 */
3259 	if (!udev->actconfig)
3260 		return 0;
3261 
3262 	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3263 			USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
3264 			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
3265 			USB_CTRL_SET_TIMEOUT);
3266 }
3267 EXPORT_SYMBOL_GPL(usb_disable_ltm);
3268 
usb_enable_ltm(struct usb_device * udev)3269 void usb_enable_ltm(struct usb_device *udev)
3270 {
3271 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3272 
3273 	/* Check if the roothub and device supports LTM. */
3274 	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
3275 			!usb_device_supports_ltm(udev))
3276 		return;
3277 
3278 	/* Set Feature LTM Enable can only be sent if the device is
3279 	 * configured.
3280 	 */
3281 	if (!udev->actconfig)
3282 		return;
3283 
3284 	usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3285 			USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
3286 			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
3287 			USB_CTRL_SET_TIMEOUT);
3288 }
3289 EXPORT_SYMBOL_GPL(usb_enable_ltm);
3290 
3291 /*
3292  * usb_enable_remote_wakeup - enable remote wakeup for a device
3293  * @udev: target device
3294  *
3295  * For USB-2 devices: Set the device's remote wakeup feature.
3296  *
3297  * For USB-3 devices: Assume there's only one function on the device and
3298  * enable remote wake for the first interface.  FIXME if the interface
3299  * association descriptor shows there's more than one function.
3300  */
usb_enable_remote_wakeup(struct usb_device * udev)3301 static int usb_enable_remote_wakeup(struct usb_device *udev)
3302 {
3303 	if (udev->speed < USB_SPEED_SUPER)
3304 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3305 				USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
3306 				USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0,
3307 				USB_CTRL_SET_TIMEOUT);
3308 	else
3309 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3310 				USB_REQ_SET_FEATURE, USB_RECIP_INTERFACE,
3311 				USB_INTRF_FUNC_SUSPEND,
3312 				USB_INTRF_FUNC_SUSPEND_RW |
3313 					USB_INTRF_FUNC_SUSPEND_LP,
3314 				NULL, 0, USB_CTRL_SET_TIMEOUT);
3315 }
3316 
3317 /*
3318  * usb_disable_remote_wakeup - disable remote wakeup for a device
3319  * @udev: target device
3320  *
3321  * For USB-2 devices: Clear the device's remote wakeup feature.
3322  *
3323  * For USB-3 devices: Assume there's only one function on the device and
3324  * disable remote wake for the first interface.  FIXME if the interface
3325  * association descriptor shows there's more than one function.
3326  */
usb_disable_remote_wakeup(struct usb_device * udev)3327 static int usb_disable_remote_wakeup(struct usb_device *udev)
3328 {
3329 	if (udev->speed < USB_SPEED_SUPER)
3330 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3331 				USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
3332 				USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0,
3333 				USB_CTRL_SET_TIMEOUT);
3334 	else
3335 		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3336 				USB_REQ_SET_FEATURE, USB_RECIP_INTERFACE,
3337 				USB_INTRF_FUNC_SUSPEND,	0, NULL, 0,
3338 				USB_CTRL_SET_TIMEOUT);
3339 }
3340 
3341 /* Count of wakeup-enabled devices at or below udev */
usb_wakeup_enabled_descendants(struct usb_device * udev)3342 unsigned usb_wakeup_enabled_descendants(struct usb_device *udev)
3343 {
3344 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
3345 
3346 	return udev->do_remote_wakeup +
3347 			(hub ? hub->wakeup_enabled_descendants : 0);
3348 }
3349 EXPORT_SYMBOL_GPL(usb_wakeup_enabled_descendants);
3350 
3351 /*
3352  * usb_port_suspend - suspend a usb device's upstream port
3353  * @udev: device that's no longer in active use, not a root hub
3354  * Context: must be able to sleep; device not locked; pm locks held
3355  *
3356  * Suspends a USB device that isn't in active use, conserving power.
3357  * Devices may wake out of a suspend, if anything important happens,
3358  * using the remote wakeup mechanism.  They may also be taken out of
3359  * suspend by the host, using usb_port_resume().  It's also routine
3360  * to disconnect devices while they are suspended.
3361  *
3362  * This only affects the USB hardware for a device; its interfaces
3363  * (and, for hubs, child devices) must already have been suspended.
3364  *
3365  * Selective port suspend reduces power; most suspended devices draw
3366  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
3367  * All devices below the suspended port are also suspended.
3368  *
3369  * Devices leave suspend state when the host wakes them up.  Some devices
3370  * also support "remote wakeup", where the device can activate the USB
3371  * tree above them to deliver data, such as a keypress or packet.  In
3372  * some cases, this wakes the USB host.
3373  *
3374  * Suspending OTG devices may trigger HNP, if that's been enabled
3375  * between a pair of dual-role devices.  That will change roles, such
3376  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
3377  *
3378  * Devices on USB hub ports have only one "suspend" state, corresponding
3379  * to ACPI D2, "may cause the device to lose some context".
3380  * State transitions include:
3381  *
3382  *   - suspend, resume ... when the VBUS power link stays live
3383  *   - suspend, disconnect ... VBUS lost
3384  *
3385  * Once VBUS drop breaks the circuit, the port it's using has to go through
3386  * normal re-enumeration procedures, starting with enabling VBUS power.
3387  * Other than re-initializing the hub (plug/unplug, except for root hubs),
3388  * Linux (2.6) currently has NO mechanisms to initiate that:  no hub_wq
3389  * timer, no SRP, no requests through sysfs.
3390  *
3391  * If Runtime PM isn't enabled or used, non-SuperSpeed devices may not get
3392  * suspended until their bus goes into global suspend (i.e., the root
3393  * hub is suspended).  Nevertheless, we change @udev->state to
3394  * USB_STATE_SUSPENDED as this is the device's "logical" state.  The actual
3395  * upstream port setting is stored in @udev->port_is_suspended.
3396  *
3397  * Returns 0 on success, else negative errno.
3398  */
usb_port_suspend(struct usb_device * udev,pm_message_t msg)3399 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
3400 {
3401 	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
3402 	struct usb_port *port_dev = hub->ports[udev->portnum - 1];
3403 	int		port1 = udev->portnum;
3404 	int		status;
3405 	bool		really_suspend = true;
3406 
3407 	usb_lock_port(port_dev);
3408 
3409 	/* enable remote wakeup when appropriate; this lets the device
3410 	 * wake up the upstream hub (including maybe the root hub).
3411 	 *
3412 	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
3413 	 * we don't explicitly enable it here.
3414 	 */
3415 	if (udev->do_remote_wakeup) {
3416 		status = usb_enable_remote_wakeup(udev);
3417 		if (status) {
3418 			dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
3419 					status);
3420 			/* bail if autosuspend is requested */
3421 			if (PMSG_IS_AUTO(msg))
3422 				goto err_wakeup;
3423 		}
3424 	}
3425 
3426 	/* disable USB2 hardware LPM */
3427 	usb_disable_usb2_hardware_lpm(udev);
3428 
3429 	if (usb_disable_ltm(udev)) {
3430 		dev_err(&udev->dev, "Failed to disable LTM before suspend\n");
3431 		status = -ENOMEM;
3432 		if (PMSG_IS_AUTO(msg))
3433 			goto err_ltm;
3434 	}
3435 
3436 	/* see 7.1.7.6 */
3437 	if (hub_is_superspeed(hub->hdev))
3438 		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U3);
3439 
3440 	/*
3441 	 * For system suspend, we do not need to enable the suspend feature
3442 	 * on individual USB-2 ports.  The devices will automatically go
3443 	 * into suspend a few ms after the root hub stops sending packets.
3444 	 * The USB 2.0 spec calls this "global suspend".
3445 	 *
3446 	 * However, many USB hubs have a bug: They don't relay wakeup requests
3447 	 * from a downstream port if the port's suspend feature isn't on.
3448 	 * Therefore we will turn on the suspend feature if udev or any of its
3449 	 * descendants is enabled for remote wakeup.
3450 	 */
3451 	else if (PMSG_IS_AUTO(msg) || usb_wakeup_enabled_descendants(udev) > 0)
3452 		status = set_port_feature(hub->hdev, port1,
3453 				USB_PORT_FEAT_SUSPEND);
3454 	else {
3455 		really_suspend = false;
3456 		status = 0;
3457 	}
3458 	if (status) {
3459 		/* Check if the port has been suspended for the timeout case
3460 		 * to prevent the suspended port from incorrect handling.
3461 		 */
3462 		if (status == -ETIMEDOUT) {
3463 			int ret;
3464 			u16 portstatus, portchange;
3465 
3466 			portstatus = portchange = 0;
3467 			ret = usb_hub_port_status(hub, port1, &portstatus,
3468 					&portchange);
3469 
3470 			dev_dbg(&port_dev->dev,
3471 				"suspend timeout, status %04x\n", portstatus);
3472 
3473 			if (ret == 0 && port_is_suspended(hub, portstatus)) {
3474 				status = 0;
3475 				goto suspend_done;
3476 			}
3477 		}
3478 
3479 		dev_dbg(&port_dev->dev, "can't suspend, status %d\n", status);
3480 
3481 		/* Try to enable USB3 LTM again */
3482 		usb_enable_ltm(udev);
3483  err_ltm:
3484 		/* Try to enable USB2 hardware LPM again */
3485 		usb_enable_usb2_hardware_lpm(udev);
3486 
3487 		if (udev->do_remote_wakeup)
3488 			(void) usb_disable_remote_wakeup(udev);
3489  err_wakeup:
3490 
3491 		/* System sleep transitions should never fail */
3492 		if (!PMSG_IS_AUTO(msg))
3493 			status = 0;
3494 	} else {
3495  suspend_done:
3496 		dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n",
3497 				(PMSG_IS_AUTO(msg) ? "auto-" : ""),
3498 				udev->do_remote_wakeup);
3499 		if (really_suspend) {
3500 			udev->port_is_suspended = 1;
3501 
3502 			/* device has up to 10 msec to fully suspend */
3503 			msleep(10);
3504 		}
3505 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
3506 	}
3507 
3508 	if (status == 0 && !udev->do_remote_wakeup && udev->persist_enabled
3509 			&& test_and_clear_bit(port1, hub->child_usage_bits))
3510 		pm_runtime_put_sync(&port_dev->dev);
3511 
3512 	usb_mark_last_busy(hub->hdev);
3513 
3514 	usb_unlock_port(port_dev);
3515 	return status;
3516 }
3517 
3518 /*
3519  * If the USB "suspend" state is in use (rather than "global suspend"),
3520  * many devices will be individually taken out of suspend state using
3521  * special "resume" signaling.  This routine kicks in shortly after
3522  * hardware resume signaling is finished, either because of selective
3523  * resume (by host) or remote wakeup (by device) ... now see what changed
3524  * in the tree that's rooted at this device.
3525  *
3526  * If @udev->reset_resume is set then the device is reset before the
3527  * status check is done.
3528  */
finish_port_resume(struct usb_device * udev)3529 static int finish_port_resume(struct usb_device *udev)
3530 {
3531 	int	status = 0;
3532 	u16	devstatus = 0;
3533 
3534 	/* caller owns the udev device lock */
3535 	dev_dbg(&udev->dev, "%s\n",
3536 		udev->reset_resume ? "finish reset-resume" : "finish resume");
3537 
3538 	/* usb ch9 identifies four variants of SUSPENDED, based on what
3539 	 * state the device resumes to.  Linux currently won't see the
3540 	 * first two on the host side; they'd be inside hub_port_init()
3541 	 * during many timeouts, but hub_wq can't suspend until later.
3542 	 */
3543 	usb_set_device_state(udev, udev->actconfig
3544 			? USB_STATE_CONFIGURED
3545 			: USB_STATE_ADDRESS);
3546 
3547 	/* 10.5.4.5 says not to reset a suspended port if the attached
3548 	 * device is enabled for remote wakeup.  Hence the reset
3549 	 * operation is carried out here, after the port has been
3550 	 * resumed.
3551 	 */
3552 	if (udev->reset_resume) {
3553 		/*
3554 		 * If the device morphs or switches modes when it is reset,
3555 		 * we don't want to perform a reset-resume.  We'll fail the
3556 		 * resume, which will cause a logical disconnect, and then
3557 		 * the device will be rediscovered.
3558 		 */
3559  retry_reset_resume:
3560 		if (udev->quirks & USB_QUIRK_RESET)
3561 			status = -ENODEV;
3562 		else
3563 			status = usb_reset_and_verify_device(udev);
3564 	}
3565 
3566 	/* 10.5.4.5 says be sure devices in the tree are still there.
3567 	 * For now let's assume the device didn't go crazy on resume,
3568 	 * and device drivers will know about any resume quirks.
3569 	 */
3570 	if (status == 0) {
3571 		devstatus = 0;
3572 		status = usb_get_std_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
3573 
3574 		/* If a normal resume failed, try doing a reset-resume */
3575 		if (status && !udev->reset_resume && udev->persist_enabled) {
3576 			dev_dbg(&udev->dev, "retry with reset-resume\n");
3577 			udev->reset_resume = 1;
3578 			goto retry_reset_resume;
3579 		}
3580 	}
3581 
3582 	if (status) {
3583 		dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
3584 				status);
3585 	/*
3586 	 * There are a few quirky devices which violate the standard
3587 	 * by claiming to have remote wakeup enabled after a reset,
3588 	 * which crash if the feature is cleared, hence check for
3589 	 * udev->reset_resume
3590 	 */
3591 	} else if (udev->actconfig && !udev->reset_resume) {
3592 		if (udev->speed < USB_SPEED_SUPER) {
3593 			if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
3594 				status = usb_disable_remote_wakeup(udev);
3595 		} else {
3596 			status = usb_get_std_status(udev, USB_RECIP_INTERFACE, 0,
3597 					&devstatus);
3598 			if (!status && devstatus & (USB_INTRF_STAT_FUNC_RW_CAP
3599 					| USB_INTRF_STAT_FUNC_RW))
3600 				status = usb_disable_remote_wakeup(udev);
3601 		}
3602 
3603 		if (status)
3604 			dev_dbg(&udev->dev,
3605 				"disable remote wakeup, status %d\n",
3606 				status);
3607 		status = 0;
3608 	}
3609 	return status;
3610 }
3611 
3612 /*
3613  * There are some SS USB devices which take longer time for link training.
3614  * XHCI specs 4.19.4 says that when Link training is successful, port
3615  * sets CCS bit to 1. So if SW reads port status before successful link
3616  * training, then it will not find device to be present.
3617  * USB Analyzer log with such buggy devices show that in some cases
3618  * device switch on the RX termination after long delay of host enabling
3619  * the VBUS. In few other cases it has been seen that device fails to
3620  * negotiate link training in first attempt. It has been
3621  * reported till now that few devices take as long as 2000 ms to train
3622  * the link after host enabling its VBUS and termination. Following
3623  * routine implements a 2000 ms timeout for link training. If in a case
3624  * link trains before timeout, loop will exit earlier.
3625  *
3626  * There are also some 2.0 hard drive based devices and 3.0 thumb
3627  * drives that, when plugged into a 2.0 only port, take a long
3628  * time to set CCS after VBUS enable.
3629  *
3630  * FIXME: If a device was connected before suspend, but was removed
3631  * while system was asleep, then the loop in the following routine will
3632  * only exit at timeout.
3633  *
3634  * This routine should only be called when persist is enabled.
3635  */
wait_for_connected(struct usb_device * udev,struct usb_hub * hub,int port1,u16 * portchange,u16 * portstatus)3636 static int wait_for_connected(struct usb_device *udev,
3637 		struct usb_hub *hub, int port1,
3638 		u16 *portchange, u16 *portstatus)
3639 {
3640 	int status = 0, delay_ms = 0;
3641 
3642 	while (delay_ms < 2000) {
3643 		if (status || *portstatus & USB_PORT_STAT_CONNECTION)
3644 			break;
3645 		if (!usb_port_is_power_on(hub, *portstatus)) {
3646 			status = -ENODEV;
3647 			break;
3648 		}
3649 		msleep(20);
3650 		delay_ms += 20;
3651 		status = usb_hub_port_status(hub, port1, portstatus, portchange);
3652 	}
3653 	dev_dbg(&udev->dev, "Waited %dms for CONNECT\n", delay_ms);
3654 	return status;
3655 }
3656 
3657 /*
3658  * usb_port_resume - re-activate a suspended usb device's upstream port
3659  * @udev: device to re-activate, not a root hub
3660  * Context: must be able to sleep; device not locked; pm locks held
3661  *
3662  * This will re-activate the suspended device, increasing power usage
3663  * while letting drivers communicate again with its endpoints.
3664  * USB resume explicitly guarantees that the power session between
3665  * the host and the device is the same as it was when the device
3666  * suspended.
3667  *
3668  * If @udev->reset_resume is set then this routine won't check that the
3669  * port is still enabled.  Furthermore, finish_port_resume() above will
3670  * reset @udev.  The end result is that a broken power session can be
3671  * recovered and @udev will appear to persist across a loss of VBUS power.
3672  *
3673  * For example, if a host controller doesn't maintain VBUS suspend current
3674  * during a system sleep or is reset when the system wakes up, all the USB
3675  * power sessions below it will be broken.  This is especially troublesome
3676  * for mass-storage devices containing mounted filesystems, since the
3677  * device will appear to have disconnected and all the memory mappings
3678  * to it will be lost.  Using the USB_PERSIST facility, the device can be
3679  * made to appear as if it had not disconnected.
3680  *
3681  * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
3682  * every effort to insure that the same device is present after the
3683  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
3684  * quite possible for a device to remain unaltered but its media to be
3685  * changed.  If the user replaces a flash memory card while the system is
3686  * asleep, he will have only himself to blame when the filesystem on the
3687  * new card is corrupted and the system crashes.
3688  *
3689  * Returns 0 on success, else negative errno.
3690  */
usb_port_resume(struct usb_device * udev,pm_message_t msg)3691 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
3692 {
3693 	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
3694 	struct usb_port *port_dev = hub->ports[udev->portnum  - 1];
3695 	int		port1 = udev->portnum;
3696 	int		status;
3697 	u16		portchange, portstatus;
3698 
3699 	if (!test_and_set_bit(port1, hub->child_usage_bits)) {
3700 		status = pm_runtime_resume_and_get(&port_dev->dev);
3701 		if (status < 0) {
3702 			dev_dbg(&udev->dev, "can't resume usb port, status %d\n",
3703 					status);
3704 			return status;
3705 		}
3706 	}
3707 
3708 	usb_lock_port(port_dev);
3709 
3710 	/* Skip the initial Clear-Suspend step for a remote wakeup */
3711 	status = usb_hub_port_status(hub, port1, &portstatus, &portchange);
3712 	if (status == 0 && !port_is_suspended(hub, portstatus)) {
3713 		if (portchange & USB_PORT_STAT_C_SUSPEND)
3714 			pm_wakeup_event(&udev->dev, 0);
3715 		goto SuspendCleared;
3716 	}
3717 
3718 	/* see 7.1.7.7; affects power usage, but not budgeting */
3719 	if (hub_is_superspeed(hub->hdev))
3720 		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U0);
3721 	else
3722 		status = usb_clear_port_feature(hub->hdev,
3723 				port1, USB_PORT_FEAT_SUSPEND);
3724 	if (status) {
3725 		dev_dbg(&port_dev->dev, "can't resume, status %d\n", status);
3726 	} else {
3727 		/* drive resume for USB_RESUME_TIMEOUT msec */
3728 		dev_dbg(&udev->dev, "usb %sresume\n",
3729 				(PMSG_IS_AUTO(msg) ? "auto-" : ""));
3730 		msleep(USB_RESUME_TIMEOUT);
3731 
3732 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
3733 		 * stop resume signaling.  Then finish the resume
3734 		 * sequence.
3735 		 */
3736 		status = usb_hub_port_status(hub, port1, &portstatus, &portchange);
3737 	}
3738 
3739  SuspendCleared:
3740 	if (status == 0) {
3741 		udev->port_is_suspended = 0;
3742 		if (hub_is_superspeed(hub->hdev)) {
3743 			if (portchange & USB_PORT_STAT_C_LINK_STATE)
3744 				usb_clear_port_feature(hub->hdev, port1,
3745 					USB_PORT_FEAT_C_PORT_LINK_STATE);
3746 		} else {
3747 			if (portchange & USB_PORT_STAT_C_SUSPEND)
3748 				usb_clear_port_feature(hub->hdev, port1,
3749 						USB_PORT_FEAT_C_SUSPEND);
3750 		}
3751 
3752 		/* TRSMRCY = 10 msec */
3753 		msleep(10);
3754 	}
3755 
3756 	if (udev->persist_enabled)
3757 		status = wait_for_connected(udev, hub, port1, &portchange,
3758 				&portstatus);
3759 
3760 	status = check_port_resume_type(udev,
3761 			hub, port1, status, portchange, portstatus);
3762 	if (status == 0)
3763 		status = finish_port_resume(udev);
3764 	if (status < 0) {
3765 		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
3766 		hub_port_logical_disconnect(hub, port1);
3767 	} else  {
3768 		/* Try to enable USB2 hardware LPM */
3769 		usb_enable_usb2_hardware_lpm(udev);
3770 
3771 		/* Try to enable USB3 LTM */
3772 		usb_enable_ltm(udev);
3773 	}
3774 
3775 	usb_unlock_port(port_dev);
3776 
3777 	return status;
3778 }
3779 
usb_remote_wakeup(struct usb_device * udev)3780 int usb_remote_wakeup(struct usb_device *udev)
3781 {
3782 	int	status = 0;
3783 
3784 	usb_lock_device(udev);
3785 	if (udev->state == USB_STATE_SUSPENDED) {
3786 		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
3787 		status = usb_autoresume_device(udev);
3788 		if (status == 0) {
3789 			/* Let the drivers do their thing, then... */
3790 			usb_autosuspend_device(udev);
3791 		}
3792 	}
3793 	usb_unlock_device(udev);
3794 	return status;
3795 }
3796 
3797 /* Returns 1 if there was a remote wakeup and a connect status change. */
hub_handle_remote_wakeup(struct usb_hub * hub,unsigned int port,u16 portstatus,u16 portchange)3798 static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
3799 		u16 portstatus, u16 portchange)
3800 		__must_hold(&port_dev->status_lock)
3801 {
3802 	struct usb_port *port_dev = hub->ports[port - 1];
3803 	struct usb_device *hdev;
3804 	struct usb_device *udev;
3805 	int connect_change = 0;
3806 	u16 link_state;
3807 	int ret;
3808 
3809 	hdev = hub->hdev;
3810 	udev = port_dev->child;
3811 	if (!hub_is_superspeed(hdev)) {
3812 		if (!(portchange & USB_PORT_STAT_C_SUSPEND))
3813 			return 0;
3814 		usb_clear_port_feature(hdev, port, USB_PORT_FEAT_C_SUSPEND);
3815 	} else {
3816 		link_state = portstatus & USB_PORT_STAT_LINK_STATE;
3817 		if (!udev || udev->state != USB_STATE_SUSPENDED ||
3818 				(link_state != USB_SS_PORT_LS_U0 &&
3819 				 link_state != USB_SS_PORT_LS_U1 &&
3820 				 link_state != USB_SS_PORT_LS_U2))
3821 			return 0;
3822 	}
3823 
3824 	if (udev) {
3825 		/* TRSMRCY = 10 msec */
3826 		msleep(10);
3827 
3828 		usb_unlock_port(port_dev);
3829 		ret = usb_remote_wakeup(udev);
3830 		usb_lock_port(port_dev);
3831 		if (ret < 0)
3832 			connect_change = 1;
3833 	} else {
3834 		ret = -ENODEV;
3835 		hub_port_disable(hub, port, 1);
3836 	}
3837 	dev_dbg(&port_dev->dev, "resume, status %d\n", ret);
3838 	return connect_change;
3839 }
3840 
check_ports_changed(struct usb_hub * hub)3841 static int check_ports_changed(struct usb_hub *hub)
3842 {
3843 	int port1;
3844 
3845 	for (port1 = 1; port1 <= hub->hdev->maxchild; ++port1) {
3846 		u16 portstatus, portchange;
3847 		int status;
3848 
3849 		status = usb_hub_port_status(hub, port1, &portstatus, &portchange);
3850 		if (!status && portchange)
3851 			return 1;
3852 	}
3853 	return 0;
3854 }
3855 
hub_suspend(struct usb_interface * intf,pm_message_t msg)3856 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
3857 {
3858 	struct usb_hub		*hub = usb_get_intfdata(intf);
3859 	struct usb_device	*hdev = hub->hdev;
3860 	unsigned		port1;
3861 
3862 	/*
3863 	 * Warn if children aren't already suspended.
3864 	 * Also, add up the number of wakeup-enabled descendants.
3865 	 */
3866 	hub->wakeup_enabled_descendants = 0;
3867 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3868 		struct usb_port *port_dev = hub->ports[port1 - 1];
3869 		struct usb_device *udev = port_dev->child;
3870 
3871 		if (udev && udev->can_submit) {
3872 			dev_warn(&port_dev->dev, "device %s not suspended yet\n",
3873 					dev_name(&udev->dev));
3874 			if (PMSG_IS_AUTO(msg))
3875 				return -EBUSY;
3876 		}
3877 		if (udev)
3878 			hub->wakeup_enabled_descendants +=
3879 					usb_wakeup_enabled_descendants(udev);
3880 	}
3881 
3882 	if (hdev->do_remote_wakeup && hub->quirk_check_port_auto_suspend) {
3883 		/* check if there are changes pending on hub ports */
3884 		if (check_ports_changed(hub)) {
3885 			if (PMSG_IS_AUTO(msg))
3886 				return -EBUSY;
3887 			pm_wakeup_event(&hdev->dev, 2000);
3888 		}
3889 	}
3890 
3891 	if (hub_is_superspeed(hdev) && hdev->do_remote_wakeup) {
3892 		/* Enable hub to send remote wakeup for all ports. */
3893 		for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3894 			set_port_feature(hdev,
3895 					 port1 |
3896 					 USB_PORT_FEAT_REMOTE_WAKE_CONNECT |
3897 					 USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT |
3898 					 USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT,
3899 					 USB_PORT_FEAT_REMOTE_WAKE_MASK);
3900 		}
3901 	}
3902 
3903 	dev_dbg(&intf->dev, "%s\n", __func__);
3904 
3905 	/* stop hub_wq and related activity */
3906 	hub_quiesce(hub, HUB_SUSPEND);
3907 	return 0;
3908 }
3909 
3910 /* Report wakeup requests from the ports of a resuming root hub */
report_wakeup_requests(struct usb_hub * hub)3911 static void report_wakeup_requests(struct usb_hub *hub)
3912 {
3913 	struct usb_device	*hdev = hub->hdev;
3914 	struct usb_device	*udev;
3915 	struct usb_hcd		*hcd;
3916 	unsigned long		resuming_ports;
3917 	int			i;
3918 
3919 	if (hdev->parent)
3920 		return;		/* Not a root hub */
3921 
3922 	hcd = bus_to_hcd(hdev->bus);
3923 	if (hcd->driver->get_resuming_ports) {
3924 
3925 		/*
3926 		 * The get_resuming_ports() method returns a bitmap (origin 0)
3927 		 * of ports which have started wakeup signaling but have not
3928 		 * yet finished resuming.  During system resume we will
3929 		 * resume all the enabled ports, regardless of any wakeup
3930 		 * signals, which means the wakeup requests would be lost.
3931 		 * To prevent this, report them to the PM core here.
3932 		 */
3933 		resuming_ports = hcd->driver->get_resuming_ports(hcd);
3934 		for (i = 0; i < hdev->maxchild; ++i) {
3935 			if (test_bit(i, &resuming_ports)) {
3936 				udev = hub->ports[i]->child;
3937 				if (udev)
3938 					pm_wakeup_event(&udev->dev, 0);
3939 			}
3940 		}
3941 	}
3942 }
3943 
hub_resume(struct usb_interface * intf)3944 static int hub_resume(struct usb_interface *intf)
3945 {
3946 	struct usb_hub *hub = usb_get_intfdata(intf);
3947 
3948 	dev_dbg(&intf->dev, "%s\n", __func__);
3949 	hub_activate(hub, HUB_RESUME);
3950 
3951 	/*
3952 	 * This should be called only for system resume, not runtime resume.
3953 	 * We can't tell the difference here, so some wakeup requests will be
3954 	 * reported at the wrong time or more than once.  This shouldn't
3955 	 * matter much, so long as they do get reported.
3956 	 */
3957 	report_wakeup_requests(hub);
3958 	return 0;
3959 }
3960 
hub_reset_resume(struct usb_interface * intf)3961 static int hub_reset_resume(struct usb_interface *intf)
3962 {
3963 	struct usb_hub *hub = usb_get_intfdata(intf);
3964 
3965 	dev_dbg(&intf->dev, "%s\n", __func__);
3966 	hub_activate(hub, HUB_RESET_RESUME);
3967 	return 0;
3968 }
3969 
3970 /**
3971  * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
3972  * @rhdev: struct usb_device for the root hub
3973  *
3974  * The USB host controller driver calls this function when its root hub
3975  * is resumed and Vbus power has been interrupted or the controller
3976  * has been reset.  The routine marks @rhdev as having lost power.
3977  * When the hub driver is resumed it will take notice and carry out
3978  * power-session recovery for all the "USB-PERSIST"-enabled child devices;
3979  * the others will be disconnected.
3980  */
usb_root_hub_lost_power(struct usb_device * rhdev)3981 void usb_root_hub_lost_power(struct usb_device *rhdev)
3982 {
3983 	dev_notice(&rhdev->dev, "root hub lost power or was reset\n");
3984 	rhdev->reset_resume = 1;
3985 }
3986 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
3987 
3988 static const char * const usb3_lpm_names[]  = {
3989 	"U0",
3990 	"U1",
3991 	"U2",
3992 	"U3",
3993 };
3994 
3995 /*
3996  * Send a Set SEL control transfer to the device, prior to enabling
3997  * device-initiated U1 or U2.  This lets the device know the exit latencies from
3998  * the time the device initiates a U1 or U2 exit, to the time it will receive a
3999  * packet from the host.
4000  *
4001  * This function will fail if the SEL or PEL values for udev are greater than
4002  * the maximum allowed values for the link state to be enabled.
4003  */
usb_req_set_sel(struct usb_device * udev)4004 static int usb_req_set_sel(struct usb_device *udev)
4005 {
4006 	struct usb_set_sel_req *sel_values;
4007 	unsigned long long u1_sel;
4008 	unsigned long long u1_pel;
4009 	unsigned long long u2_sel;
4010 	unsigned long long u2_pel;
4011 	int ret;
4012 
4013 	if (!udev->parent || udev->speed < USB_SPEED_SUPER || !udev->lpm_capable)
4014 		return 0;
4015 
4016 	/* Convert SEL and PEL stored in ns to us */
4017 	u1_sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
4018 	u1_pel = DIV_ROUND_UP(udev->u1_params.pel, 1000);
4019 	u2_sel = DIV_ROUND_UP(udev->u2_params.sel, 1000);
4020 	u2_pel = DIV_ROUND_UP(udev->u2_params.pel, 1000);
4021 
4022 	/*
4023 	 * Make sure that the calculated SEL and PEL values for the link
4024 	 * state we're enabling aren't bigger than the max SEL/PEL
4025 	 * value that will fit in the SET SEL control transfer.
4026 	 * Otherwise the device would get an incorrect idea of the exit
4027 	 * latency for the link state, and could start a device-initiated
4028 	 * U1/U2 when the exit latencies are too high.
4029 	 */
4030 	if (u1_sel > USB3_LPM_MAX_U1_SEL_PEL ||
4031 	    u1_pel > USB3_LPM_MAX_U1_SEL_PEL ||
4032 	    u2_sel > USB3_LPM_MAX_U2_SEL_PEL ||
4033 	    u2_pel > USB3_LPM_MAX_U2_SEL_PEL) {
4034 		dev_dbg(&udev->dev, "Device-initiated U1/U2 disabled due to long SEL or PEL\n");
4035 		return -EINVAL;
4036 	}
4037 
4038 	/*
4039 	 * usb_enable_lpm() can be called as part of a failed device reset,
4040 	 * which may be initiated by an error path of a mass storage driver.
4041 	 * Therefore, use GFP_NOIO.
4042 	 */
4043 	sel_values = kmalloc(sizeof *(sel_values), GFP_NOIO);
4044 	if (!sel_values)
4045 		return -ENOMEM;
4046 
4047 	sel_values->u1_sel = u1_sel;
4048 	sel_values->u1_pel = u1_pel;
4049 	sel_values->u2_sel = cpu_to_le16(u2_sel);
4050 	sel_values->u2_pel = cpu_to_le16(u2_pel);
4051 
4052 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
4053 			USB_REQ_SET_SEL,
4054 			USB_RECIP_DEVICE,
4055 			0, 0,
4056 			sel_values, sizeof *(sel_values),
4057 			USB_CTRL_SET_TIMEOUT);
4058 	kfree(sel_values);
4059 
4060 	if (ret > 0)
4061 		udev->lpm_devinit_allow = 1;
4062 
4063 	return ret;
4064 }
4065 
4066 /*
4067  * Enable or disable device-initiated U1 or U2 transitions.
4068  */
usb_set_device_initiated_lpm(struct usb_device * udev,enum usb3_link_state state,bool enable)4069 static int usb_set_device_initiated_lpm(struct usb_device *udev,
4070 		enum usb3_link_state state, bool enable)
4071 {
4072 	int ret;
4073 	int feature;
4074 
4075 	switch (state) {
4076 	case USB3_LPM_U1:
4077 		feature = USB_DEVICE_U1_ENABLE;
4078 		break;
4079 	case USB3_LPM_U2:
4080 		feature = USB_DEVICE_U2_ENABLE;
4081 		break;
4082 	default:
4083 		dev_warn(&udev->dev, "%s: Can't %s non-U1 or U2 state.\n",
4084 				__func__, enable ? "enable" : "disable");
4085 		return -EINVAL;
4086 	}
4087 
4088 	if (udev->state != USB_STATE_CONFIGURED) {
4089 		dev_dbg(&udev->dev, "%s: Can't %s %s state "
4090 				"for unconfigured device.\n",
4091 				__func__, enable ? "enable" : "disable",
4092 				usb3_lpm_names[state]);
4093 		return 0;
4094 	}
4095 
4096 	if (enable) {
4097 		/*
4098 		 * Now send the control transfer to enable device-initiated LPM
4099 		 * for either U1 or U2.
4100 		 */
4101 		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
4102 				USB_REQ_SET_FEATURE,
4103 				USB_RECIP_DEVICE,
4104 				feature,
4105 				0, NULL, 0,
4106 				USB_CTRL_SET_TIMEOUT);
4107 	} else {
4108 		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
4109 				USB_REQ_CLEAR_FEATURE,
4110 				USB_RECIP_DEVICE,
4111 				feature,
4112 				0, NULL, 0,
4113 				USB_CTRL_SET_TIMEOUT);
4114 	}
4115 	if (ret < 0) {
4116 		dev_warn(&udev->dev, "%s of device-initiated %s failed.\n",
4117 				enable ? "Enable" : "Disable",
4118 				usb3_lpm_names[state]);
4119 		return -EBUSY;
4120 	}
4121 	return 0;
4122 }
4123 
usb_set_lpm_timeout(struct usb_device * udev,enum usb3_link_state state,int timeout)4124 static int usb_set_lpm_timeout(struct usb_device *udev,
4125 		enum usb3_link_state state, int timeout)
4126 {
4127 	int ret;
4128 	int feature;
4129 
4130 	switch (state) {
4131 	case USB3_LPM_U1:
4132 		feature = USB_PORT_FEAT_U1_TIMEOUT;
4133 		break;
4134 	case USB3_LPM_U2:
4135 		feature = USB_PORT_FEAT_U2_TIMEOUT;
4136 		break;
4137 	default:
4138 		dev_warn(&udev->dev, "%s: Can't set timeout for non-U1 or U2 state.\n",
4139 				__func__);
4140 		return -EINVAL;
4141 	}
4142 
4143 	if (state == USB3_LPM_U1 && timeout > USB3_LPM_U1_MAX_TIMEOUT &&
4144 			timeout != USB3_LPM_DEVICE_INITIATED) {
4145 		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x, "
4146 				"which is a reserved value.\n",
4147 				usb3_lpm_names[state], timeout);
4148 		return -EINVAL;
4149 	}
4150 
4151 	ret = set_port_feature(udev->parent,
4152 			USB_PORT_LPM_TIMEOUT(timeout) | udev->portnum,
4153 			feature);
4154 	if (ret < 0) {
4155 		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x,"
4156 				"error code %i\n", usb3_lpm_names[state],
4157 				timeout, ret);
4158 		return -EBUSY;
4159 	}
4160 	if (state == USB3_LPM_U1)
4161 		udev->u1_params.timeout = timeout;
4162 	else
4163 		udev->u2_params.timeout = timeout;
4164 	return 0;
4165 }
4166 
4167 /*
4168  * Don't allow device intiated U1/U2 if the system exit latency + one bus
4169  * interval is greater than the minimum service interval of any active
4170  * periodic endpoint. See USB 3.2 section 9.4.9
4171  */
usb_device_may_initiate_lpm(struct usb_device * udev,enum usb3_link_state state)4172 static bool usb_device_may_initiate_lpm(struct usb_device *udev,
4173 					enum usb3_link_state state)
4174 {
4175 	unsigned int sel;		/* us */
4176 	int i, j;
4177 
4178 	if (!udev->lpm_devinit_allow)
4179 		return false;
4180 
4181 	if (state == USB3_LPM_U1)
4182 		sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
4183 	else if (state == USB3_LPM_U2)
4184 		sel = DIV_ROUND_UP(udev->u2_params.sel, 1000);
4185 	else
4186 		return false;
4187 
4188 	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
4189 		struct usb_interface *intf;
4190 		struct usb_endpoint_descriptor *desc;
4191 		unsigned int interval;
4192 
4193 		intf = udev->actconfig->interface[i];
4194 		if (!intf)
4195 			continue;
4196 
4197 		for (j = 0; j < intf->cur_altsetting->desc.bNumEndpoints; j++) {
4198 			desc = &intf->cur_altsetting->endpoint[j].desc;
4199 
4200 			if (usb_endpoint_xfer_int(desc) ||
4201 			    usb_endpoint_xfer_isoc(desc)) {
4202 				interval = (1 << (desc->bInterval - 1)) * 125;
4203 				if (sel + 125 > interval)
4204 					return false;
4205 			}
4206 		}
4207 	}
4208 	return true;
4209 }
4210 
4211 /*
4212  * Enable the hub-initiated U1/U2 idle timeouts, and enable device-initiated
4213  * U1/U2 entry.
4214  *
4215  * We will attempt to enable U1 or U2, but there are no guarantees that the
4216  * control transfers to set the hub timeout or enable device-initiated U1/U2
4217  * will be successful.
4218  *
4219  * If the control transfer to enable device-initiated U1/U2 entry fails, then
4220  * hub-initiated U1/U2 will be disabled.
4221  *
4222  * If we cannot set the parent hub U1/U2 timeout, we attempt to let the xHCI
4223  * driver know about it.  If that call fails, it should be harmless, and just
4224  * take up more slightly more bus bandwidth for unnecessary U1/U2 exit latency.
4225  */
usb_enable_link_state(struct usb_hcd * hcd,struct usb_device * udev,enum usb3_link_state state)4226 static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
4227 		enum usb3_link_state state)
4228 {
4229 	int timeout;
4230 	__u8 u1_mel;
4231 	__le16 u2_mel;
4232 
4233 	/* Skip if the device BOS descriptor couldn't be read */
4234 	if (!udev->bos)
4235 		return;
4236 
4237 	u1_mel = udev->bos->ss_cap->bU1devExitLat;
4238 	u2_mel = udev->bos->ss_cap->bU2DevExitLat;
4239 
4240 	/* If the device says it doesn't have *any* exit latency to come out of
4241 	 * U1 or U2, it's probably lying.  Assume it doesn't implement that link
4242 	 * state.
4243 	 */
4244 	if ((state == USB3_LPM_U1 && u1_mel == 0) ||
4245 			(state == USB3_LPM_U2 && u2_mel == 0))
4246 		return;
4247 
4248 	/* We allow the host controller to set the U1/U2 timeout internally
4249 	 * first, so that it can change its schedule to account for the
4250 	 * additional latency to send data to a device in a lower power
4251 	 * link state.
4252 	 */
4253 	timeout = hcd->driver->enable_usb3_lpm_timeout(hcd, udev, state);
4254 
4255 	/* xHCI host controller doesn't want to enable this LPM state. */
4256 	if (timeout == 0)
4257 		return;
4258 
4259 	if (timeout < 0) {
4260 		dev_warn(&udev->dev, "Could not enable %s link state, "
4261 				"xHCI error %i.\n", usb3_lpm_names[state],
4262 				timeout);
4263 		return;
4264 	}
4265 
4266 	if (usb_set_lpm_timeout(udev, state, timeout)) {
4267 		/* If we can't set the parent hub U1/U2 timeout,
4268 		 * device-initiated LPM won't be allowed either, so let the xHCI
4269 		 * host know that this link state won't be enabled.
4270 		 */
4271 		hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);
4272 		return;
4273 	}
4274 
4275 	/* Only a configured device will accept the Set Feature
4276 	 * U1/U2_ENABLE
4277 	 */
4278 	if (udev->actconfig &&
4279 	    usb_device_may_initiate_lpm(udev, state)) {
4280 		if (usb_set_device_initiated_lpm(udev, state, true)) {
4281 			/*
4282 			 * Request to enable device initiated U1/U2 failed,
4283 			 * better to turn off lpm in this case.
4284 			 */
4285 			usb_set_lpm_timeout(udev, state, 0);
4286 			hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);
4287 			return;
4288 		}
4289 	}
4290 
4291 	if (state == USB3_LPM_U1)
4292 		udev->usb3_lpm_u1_enabled = 1;
4293 	else if (state == USB3_LPM_U2)
4294 		udev->usb3_lpm_u2_enabled = 1;
4295 }
4296 /*
4297  * Disable the hub-initiated U1/U2 idle timeouts, and disable device-initiated
4298  * U1/U2 entry.
4299  *
4300  * If this function returns -EBUSY, the parent hub will still allow U1/U2 entry.
4301  * If zero is returned, the parent will not allow the link to go into U1/U2.
4302  *
4303  * If zero is returned, device-initiated U1/U2 entry may still be enabled, but
4304  * it won't have an effect on the bus link state because the parent hub will
4305  * still disallow device-initiated U1/U2 entry.
4306  *
4307  * If zero is returned, the xHCI host controller may still think U1/U2 entry is
4308  * possible.  The result will be slightly more bus bandwidth will be taken up
4309  * (to account for U1/U2 exit latency), but it should be harmless.
4310  */
usb_disable_link_state(struct usb_hcd * hcd,struct usb_device * udev,enum usb3_link_state state)4311 static int usb_disable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
4312 		enum usb3_link_state state)
4313 {
4314 	switch (state) {
4315 	case USB3_LPM_U1:
4316 	case USB3_LPM_U2:
4317 		break;
4318 	default:
4319 		dev_warn(&udev->dev, "%s: Can't disable non-U1 or U2 state.\n",
4320 				__func__);
4321 		return -EINVAL;
4322 	}
4323 
4324 	if (usb_set_lpm_timeout(udev, state, 0))
4325 		return -EBUSY;
4326 
4327 	usb_set_device_initiated_lpm(udev, state, false);
4328 
4329 	if (hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state))
4330 		dev_warn(&udev->dev, "Could not disable xHCI %s timeout, "
4331 				"bus schedule bandwidth may be impacted.\n",
4332 				usb3_lpm_names[state]);
4333 
4334 	/* As soon as usb_set_lpm_timeout(0) return 0, hub initiated LPM
4335 	 * is disabled. Hub will disallows link to enter U1/U2 as well,
4336 	 * even device is initiating LPM. Hence LPM is disabled if hub LPM
4337 	 * timeout set to 0, no matter device-initiated LPM is disabled or
4338 	 * not.
4339 	 */
4340 	if (state == USB3_LPM_U1)
4341 		udev->usb3_lpm_u1_enabled = 0;
4342 	else if (state == USB3_LPM_U2)
4343 		udev->usb3_lpm_u2_enabled = 0;
4344 
4345 	return 0;
4346 }
4347 
4348 /*
4349  * Disable hub-initiated and device-initiated U1 and U2 entry.
4350  * Caller must own the bandwidth_mutex.
4351  *
4352  * This will call usb_enable_lpm() on failure, which will decrement
4353  * lpm_disable_count, and will re-enable LPM if lpm_disable_count reaches zero.
4354  */
usb_disable_lpm(struct usb_device * udev)4355 int usb_disable_lpm(struct usb_device *udev)
4356 {
4357 	struct usb_hcd *hcd;
4358 
4359 	if (!udev || !udev->parent ||
4360 			udev->speed < USB_SPEED_SUPER ||
4361 			!udev->lpm_capable ||
4362 			udev->state < USB_STATE_CONFIGURED)
4363 		return 0;
4364 
4365 	hcd = bus_to_hcd(udev->bus);
4366 	if (!hcd || !hcd->driver->disable_usb3_lpm_timeout)
4367 		return 0;
4368 
4369 	udev->lpm_disable_count++;
4370 	if ((udev->u1_params.timeout == 0 && udev->u2_params.timeout == 0))
4371 		return 0;
4372 
4373 	/* If LPM is enabled, attempt to disable it. */
4374 	if (usb_disable_link_state(hcd, udev, USB3_LPM_U1))
4375 		goto enable_lpm;
4376 	if (usb_disable_link_state(hcd, udev, USB3_LPM_U2))
4377 		goto enable_lpm;
4378 
4379 	return 0;
4380 
4381 enable_lpm:
4382 	usb_enable_lpm(udev);
4383 	return -EBUSY;
4384 }
4385 EXPORT_SYMBOL_GPL(usb_disable_lpm);
4386 
4387 /* Grab the bandwidth_mutex before calling usb_disable_lpm() */
usb_unlocked_disable_lpm(struct usb_device * udev)4388 int usb_unlocked_disable_lpm(struct usb_device *udev)
4389 {
4390 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4391 	int ret;
4392 
4393 	if (!hcd)
4394 		return -EINVAL;
4395 
4396 	mutex_lock(hcd->bandwidth_mutex);
4397 	ret = usb_disable_lpm(udev);
4398 	mutex_unlock(hcd->bandwidth_mutex);
4399 
4400 	return ret;
4401 }
4402 EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
4403 
4404 /*
4405  * Attempt to enable device-initiated and hub-initiated U1 and U2 entry.  The
4406  * xHCI host policy may prevent U1 or U2 from being enabled.
4407  *
4408  * Other callers may have disabled link PM, so U1 and U2 entry will be disabled
4409  * until the lpm_disable_count drops to zero.  Caller must own the
4410  * bandwidth_mutex.
4411  */
usb_enable_lpm(struct usb_device * udev)4412 void usb_enable_lpm(struct usb_device *udev)
4413 {
4414 	struct usb_hcd *hcd;
4415 	struct usb_hub *hub;
4416 	struct usb_port *port_dev;
4417 
4418 	if (!udev || !udev->parent ||
4419 			udev->speed < USB_SPEED_SUPER ||
4420 			!udev->lpm_capable ||
4421 			udev->state < USB_STATE_CONFIGURED)
4422 		return;
4423 
4424 	udev->lpm_disable_count--;
4425 	hcd = bus_to_hcd(udev->bus);
4426 	/* Double check that we can both enable and disable LPM.
4427 	 * Device must be configured to accept set feature U1/U2 timeout.
4428 	 */
4429 	if (!hcd || !hcd->driver->enable_usb3_lpm_timeout ||
4430 			!hcd->driver->disable_usb3_lpm_timeout)
4431 		return;
4432 
4433 	if (udev->lpm_disable_count > 0)
4434 		return;
4435 
4436 	hub = usb_hub_to_struct_hub(udev->parent);
4437 	if (!hub)
4438 		return;
4439 
4440 	port_dev = hub->ports[udev->portnum - 1];
4441 
4442 	if (port_dev->usb3_lpm_u1_permit)
4443 		usb_enable_link_state(hcd, udev, USB3_LPM_U1);
4444 
4445 	if (port_dev->usb3_lpm_u2_permit)
4446 		usb_enable_link_state(hcd, udev, USB3_LPM_U2);
4447 }
4448 EXPORT_SYMBOL_GPL(usb_enable_lpm);
4449 
4450 /* Grab the bandwidth_mutex before calling usb_enable_lpm() */
usb_unlocked_enable_lpm(struct usb_device * udev)4451 void usb_unlocked_enable_lpm(struct usb_device *udev)
4452 {
4453 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4454 
4455 	if (!hcd)
4456 		return;
4457 
4458 	mutex_lock(hcd->bandwidth_mutex);
4459 	usb_enable_lpm(udev);
4460 	mutex_unlock(hcd->bandwidth_mutex);
4461 }
4462 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
4463 
4464 /* usb3 devices use U3 for disabled, make sure remote wakeup is disabled */
hub_usb3_port_prepare_disable(struct usb_hub * hub,struct usb_port * port_dev)4465 static void hub_usb3_port_prepare_disable(struct usb_hub *hub,
4466 					  struct usb_port *port_dev)
4467 {
4468 	struct usb_device *udev = port_dev->child;
4469 	int ret;
4470 
4471 	if (udev && udev->port_is_suspended && udev->do_remote_wakeup) {
4472 		ret = hub_set_port_link_state(hub, port_dev->portnum,
4473 					      USB_SS_PORT_LS_U0);
4474 		if (!ret) {
4475 			msleep(USB_RESUME_TIMEOUT);
4476 			ret = usb_disable_remote_wakeup(udev);
4477 		}
4478 		if (ret)
4479 			dev_warn(&udev->dev,
4480 				 "Port disable: can't disable remote wake\n");
4481 		udev->do_remote_wakeup = 0;
4482 	}
4483 }
4484 
4485 #else	/* CONFIG_PM */
4486 
4487 #define hub_suspend		NULL
4488 #define hub_resume		NULL
4489 #define hub_reset_resume	NULL
4490 
hub_usb3_port_prepare_disable(struct usb_hub * hub,struct usb_port * port_dev)4491 static inline void hub_usb3_port_prepare_disable(struct usb_hub *hub,
4492 						 struct usb_port *port_dev) { }
4493 
usb_disable_lpm(struct usb_device * udev)4494 int usb_disable_lpm(struct usb_device *udev)
4495 {
4496 	return 0;
4497 }
4498 EXPORT_SYMBOL_GPL(usb_disable_lpm);
4499 
usb_enable_lpm(struct usb_device * udev)4500 void usb_enable_lpm(struct usb_device *udev) { }
4501 EXPORT_SYMBOL_GPL(usb_enable_lpm);
4502 
usb_unlocked_disable_lpm(struct usb_device * udev)4503 int usb_unlocked_disable_lpm(struct usb_device *udev)
4504 {
4505 	return 0;
4506 }
4507 EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
4508 
usb_unlocked_enable_lpm(struct usb_device * udev)4509 void usb_unlocked_enable_lpm(struct usb_device *udev) { }
4510 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
4511 
usb_disable_ltm(struct usb_device * udev)4512 int usb_disable_ltm(struct usb_device *udev)
4513 {
4514 	return 0;
4515 }
4516 EXPORT_SYMBOL_GPL(usb_disable_ltm);
4517 
usb_enable_ltm(struct usb_device * udev)4518 void usb_enable_ltm(struct usb_device *udev) { }
4519 EXPORT_SYMBOL_GPL(usb_enable_ltm);
4520 
hub_handle_remote_wakeup(struct usb_hub * hub,unsigned int port,u16 portstatus,u16 portchange)4521 static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
4522 		u16 portstatus, u16 portchange)
4523 {
4524 	return 0;
4525 }
4526 
usb_req_set_sel(struct usb_device * udev)4527 static int usb_req_set_sel(struct usb_device *udev)
4528 {
4529 	return 0;
4530 }
4531 
4532 #endif	/* CONFIG_PM */
4533 
4534 /*
4535  * USB-3 does not have a similar link state as USB-2 that will avoid negotiating
4536  * a connection with a plugged-in cable but will signal the host when the cable
4537  * is unplugged. Disable remote wake and set link state to U3 for USB-3 devices
4538  */
hub_port_disable(struct usb_hub * hub,int port1,int set_state)4539 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
4540 {
4541 	struct usb_port *port_dev = hub->ports[port1 - 1];
4542 	struct usb_device *hdev = hub->hdev;
4543 	int ret = 0;
4544 
4545 	if (!hub->error) {
4546 		if (hub_is_superspeed(hub->hdev)) {
4547 			hub_usb3_port_prepare_disable(hub, port_dev);
4548 			ret = hub_set_port_link_state(hub, port_dev->portnum,
4549 						      USB_SS_PORT_LS_U3);
4550 		} else {
4551 			ret = usb_clear_port_feature(hdev, port1,
4552 					USB_PORT_FEAT_ENABLE);
4553 		}
4554 	}
4555 	if (port_dev->child && set_state)
4556 		usb_set_device_state(port_dev->child, USB_STATE_NOTATTACHED);
4557 	if (ret && ret != -ENODEV)
4558 		dev_err(&port_dev->dev, "cannot disable (err = %d)\n", ret);
4559 	return ret;
4560 }
4561 
4562 /*
4563  * usb_port_disable - disable a usb device's upstream port
4564  * @udev: device to disable
4565  * Context: @udev locked, must be able to sleep.
4566  *
4567  * Disables a USB device that isn't in active use.
4568  */
usb_port_disable(struct usb_device * udev)4569 int usb_port_disable(struct usb_device *udev)
4570 {
4571 	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
4572 
4573 	return hub_port_disable(hub, udev->portnum, 0);
4574 }
4575 
4576 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
4577  *
4578  * Between connect detection and reset signaling there must be a delay
4579  * of 100ms at least for debounce and power-settling.  The corresponding
4580  * timer shall restart whenever the downstream port detects a disconnect.
4581  *
4582  * Apparently there are some bluetooth and irda-dongles and a number of
4583  * low-speed devices for which this debounce period may last over a second.
4584  * Not covered by the spec - but easy to deal with.
4585  *
4586  * This implementation uses a 1500ms total debounce timeout; if the
4587  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
4588  * every 25ms for transient disconnects.  When the port status has been
4589  * unchanged for 100ms it returns the port status.
4590  */
hub_port_debounce(struct usb_hub * hub,int port1,bool must_be_connected)4591 int hub_port_debounce(struct usb_hub *hub, int port1, bool must_be_connected)
4592 {
4593 	int ret;
4594 	u16 portchange, portstatus;
4595 	unsigned connection = 0xffff;
4596 	int total_time, stable_time = 0;
4597 	struct usb_port *port_dev = hub->ports[port1 - 1];
4598 
4599 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
4600 		ret = usb_hub_port_status(hub, port1, &portstatus, &portchange);
4601 		if (ret < 0)
4602 			return ret;
4603 
4604 		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
4605 		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
4606 			if (!must_be_connected ||
4607 			     (connection == USB_PORT_STAT_CONNECTION))
4608 				stable_time += HUB_DEBOUNCE_STEP;
4609 			if (stable_time >= HUB_DEBOUNCE_STABLE)
4610 				break;
4611 		} else {
4612 			stable_time = 0;
4613 			connection = portstatus & USB_PORT_STAT_CONNECTION;
4614 		}
4615 
4616 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
4617 			usb_clear_port_feature(hub->hdev, port1,
4618 					USB_PORT_FEAT_C_CONNECTION);
4619 		}
4620 
4621 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
4622 			break;
4623 		msleep(HUB_DEBOUNCE_STEP);
4624 	}
4625 
4626 	dev_dbg(&port_dev->dev, "debounce total %dms stable %dms status 0x%x\n",
4627 			total_time, stable_time, portstatus);
4628 
4629 	if (stable_time < HUB_DEBOUNCE_STABLE)
4630 		return -ETIMEDOUT;
4631 	return portstatus;
4632 }
4633 
usb_ep0_reinit(struct usb_device * udev)4634 void usb_ep0_reinit(struct usb_device *udev)
4635 {
4636 	usb_disable_endpoint(udev, 0 + USB_DIR_IN, true);
4637 	usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true);
4638 	usb_enable_endpoint(udev, &udev->ep0, true);
4639 }
4640 EXPORT_SYMBOL_GPL(usb_ep0_reinit);
4641 
4642 #define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
4643 #define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)
4644 
hub_set_address(struct usb_device * udev,int devnum)4645 static int hub_set_address(struct usb_device *udev, int devnum)
4646 {
4647 	int retval;
4648 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4649 
4650 	/*
4651 	 * The host controller will choose the device address,
4652 	 * instead of the core having chosen it earlier
4653 	 */
4654 	if (!hcd->driver->address_device && devnum <= 1)
4655 		return -EINVAL;
4656 	if (udev->state == USB_STATE_ADDRESS)
4657 		return 0;
4658 	if (udev->state != USB_STATE_DEFAULT)
4659 		return -EINVAL;
4660 	if (hcd->driver->address_device)
4661 		retval = hcd->driver->address_device(hcd, udev);
4662 	else
4663 		retval = usb_control_msg(udev, usb_sndaddr0pipe(),
4664 				USB_REQ_SET_ADDRESS, 0, devnum, 0,
4665 				NULL, 0, USB_CTRL_SET_TIMEOUT);
4666 	if (retval == 0) {
4667 		update_devnum(udev, devnum);
4668 		/* Device now using proper address. */
4669 		usb_set_device_state(udev, USB_STATE_ADDRESS);
4670 		usb_ep0_reinit(udev);
4671 	}
4672 	return retval;
4673 }
4674 
4675 /*
4676  * There are reports of USB 3.0 devices that say they support USB 2.0 Link PM
4677  * when they're plugged into a USB 2.0 port, but they don't work when LPM is
4678  * enabled.
4679  *
4680  * Only enable USB 2.0 Link PM if the port is internal (hardwired), or the
4681  * device says it supports the new USB 2.0 Link PM errata by setting the BESL
4682  * support bit in the BOS descriptor.
4683  */
hub_set_initial_usb2_lpm_policy(struct usb_device * udev)4684 static void hub_set_initial_usb2_lpm_policy(struct usb_device *udev)
4685 {
4686 	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
4687 	int connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
4688 
4689 	if (!udev->usb2_hw_lpm_capable || !udev->bos)
4690 		return;
4691 
4692 	if (hub)
4693 		connect_type = hub->ports[udev->portnum - 1]->connect_type;
4694 
4695 	if ((udev->bos->ext_cap->bmAttributes & cpu_to_le32(USB_BESL_SUPPORT)) ||
4696 			connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
4697 		udev->usb2_hw_lpm_allowed = 1;
4698 		usb_enable_usb2_hardware_lpm(udev);
4699 	}
4700 }
4701 
hub_enable_device(struct usb_device * udev)4702 static int hub_enable_device(struct usb_device *udev)
4703 {
4704 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4705 
4706 	if (!hcd->driver->enable_device)
4707 		return 0;
4708 	if (udev->state == USB_STATE_ADDRESS)
4709 		return 0;
4710 	if (udev->state != USB_STATE_DEFAULT)
4711 		return -EINVAL;
4712 
4713 	return hcd->driver->enable_device(hcd, udev);
4714 }
4715 
4716 /*
4717  * Get the bMaxPacketSize0 value during initialization by reading the
4718  * device's device descriptor.  Since we don't already know this value,
4719  * the transfer is unsafe and it ignores I/O errors, only testing for
4720  * reasonable received values.
4721  *
4722  * For "old scheme" initialization, size will be 8 so we read just the
4723  * start of the device descriptor, which should work okay regardless of
4724  * the actual bMaxPacketSize0 value.  For "new scheme" initialization,
4725  * size will be 64 (and buf will point to a sufficiently large buffer),
4726  * which might not be kosher according to the USB spec but it's what
4727  * Windows does and what many devices expect.
4728  *
4729  * Returns: bMaxPacketSize0 or a negative error code.
4730  */
get_bMaxPacketSize0(struct usb_device * udev,struct usb_device_descriptor * buf,int size,bool first_time)4731 static int get_bMaxPacketSize0(struct usb_device *udev,
4732 		struct usb_device_descriptor *buf, int size, bool first_time)
4733 {
4734 	int i, rc;
4735 
4736 	/*
4737 	 * Retry on all errors; some devices are flakey.
4738 	 * 255 is for WUSB devices, we actually need to use
4739 	 * 512 (WUSB1.0[4.8.1]).
4740 	 */
4741 	for (i = 0; i < GET_MAXPACKET0_TRIES; ++i) {
4742 		/* Start with invalid values in case the transfer fails */
4743 		buf->bDescriptorType = buf->bMaxPacketSize0 = 0;
4744 		rc = usb_control_msg(udev, usb_rcvaddr0pipe(),
4745 				USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
4746 				USB_DT_DEVICE << 8, 0,
4747 				buf, size,
4748 				initial_descriptor_timeout);
4749 		switch (buf->bMaxPacketSize0) {
4750 		case 8: case 16: case 32: case 64: case 9:
4751 			if (buf->bDescriptorType == USB_DT_DEVICE) {
4752 				rc = buf->bMaxPacketSize0;
4753 				break;
4754 			}
4755 			fallthrough;
4756 		default:
4757 			if (rc >= 0)
4758 				rc = -EPROTO;
4759 			break;
4760 		}
4761 
4762 		/*
4763 		 * Some devices time out if they are powered on
4764 		 * when already connected. They need a second
4765 		 * reset, so return early. But only on the first
4766 		 * attempt, lest we get into a time-out/reset loop.
4767 		 */
4768 		if (rc > 0 || (rc == -ETIMEDOUT && first_time &&
4769 				udev->speed > USB_SPEED_FULL))
4770 			break;
4771 	}
4772 	return rc;
4773 }
4774 
4775 #define GET_DESCRIPTOR_BUFSIZE	64
4776 
4777 /* Reset device, (re)assign address, get device descriptor.
4778  * Device connection must be stable, no more debouncing needed.
4779  * Returns device in USB_STATE_ADDRESS, except on error.
4780  *
4781  * If this is called for an already-existing device (as part of
4782  * usb_reset_and_verify_device), the caller must own the device lock and
4783  * the port lock.  For a newly detected device that is not accessible
4784  * through any global pointers, it's not necessary to lock the device,
4785  * but it is still necessary to lock the port.
4786  *
4787  * For a newly detected device, @dev_descr must be NULL.  The device
4788  * descriptor retrieved from the device will then be stored in
4789  * @udev->descriptor.  For an already existing device, @dev_descr
4790  * must be non-NULL.  The device descriptor will be stored there,
4791  * not in @udev->descriptor, because descriptors for registered
4792  * devices are meant to be immutable.
4793  */
4794 static int
hub_port_init(struct usb_hub * hub,struct usb_device * udev,int port1,int retry_counter,struct usb_device_descriptor * dev_descr)4795 hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
4796 		int retry_counter, struct usb_device_descriptor *dev_descr)
4797 {
4798 	struct usb_device	*hdev = hub->hdev;
4799 	struct usb_hcd		*hcd = bus_to_hcd(hdev->bus);
4800 	struct usb_port		*port_dev = hub->ports[port1 - 1];
4801 	int			retries, operations, retval, i;
4802 	unsigned		delay = HUB_SHORT_RESET_TIME;
4803 	enum usb_device_speed	oldspeed = udev->speed;
4804 	const char		*speed;
4805 	int			devnum = udev->devnum;
4806 	const char		*driver_name;
4807 	bool			do_new_scheme;
4808 	const bool		initial = !dev_descr;
4809 	int			maxp0;
4810 	struct usb_device_descriptor	*buf, *descr;
4811 
4812 	buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
4813 	if (!buf)
4814 		return -ENOMEM;
4815 
4816 	/* root hub ports have a slightly longer reset period
4817 	 * (from USB 2.0 spec, section 7.1.7.5)
4818 	 */
4819 	if (!hdev->parent) {
4820 		delay = HUB_ROOT_RESET_TIME;
4821 		if (port1 == hdev->bus->otg_port)
4822 			hdev->bus->b_hnp_enable = 0;
4823 	}
4824 
4825 	/* Some low speed devices have problems with the quick delay, so */
4826 	/*  be a bit pessimistic with those devices. RHbug #23670 */
4827 	if (oldspeed == USB_SPEED_LOW)
4828 		delay = HUB_LONG_RESET_TIME;
4829 
4830 	/* Reset the device; full speed may morph to high speed */
4831 	/* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
4832 	retval = hub_port_reset(hub, port1, udev, delay, false);
4833 	if (retval < 0)		/* error or disconnect */
4834 		goto fail;
4835 	/* success, speed is known */
4836 
4837 	retval = -ENODEV;
4838 
4839 	/* Don't allow speed changes at reset, except usb 3.0 to faster */
4840 	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed &&
4841 	    !(oldspeed == USB_SPEED_SUPER && udev->speed > oldspeed)) {
4842 		dev_dbg(&udev->dev, "device reset changed speed!\n");
4843 		goto fail;
4844 	}
4845 	oldspeed = udev->speed;
4846 
4847 	if (initial) {
4848 		/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
4849 		 * it's fixed size except for full speed devices.
4850 		 */
4851 		switch (udev->speed) {
4852 		case USB_SPEED_SUPER_PLUS:
4853 		case USB_SPEED_SUPER:
4854 			udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
4855 			break;
4856 		case USB_SPEED_HIGH:		/* fixed at 64 */
4857 			udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4858 			break;
4859 		case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
4860 			/* to determine the ep0 maxpacket size, try to read
4861 			 * the device descriptor to get bMaxPacketSize0 and
4862 			 * then correct our initial guess.
4863 			 */
4864 			udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4865 			break;
4866 		case USB_SPEED_LOW:		/* fixed at 8 */
4867 			udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8);
4868 			break;
4869 		default:
4870 			goto fail;
4871 		}
4872 	}
4873 
4874 	speed = usb_speed_string(udev->speed);
4875 
4876 	/*
4877 	 * The controller driver may be NULL if the controller device
4878 	 * is the middle device between platform device and roothub.
4879 	 * This middle device may not need a device driver due to
4880 	 * all hardware control can be at platform device driver, this
4881 	 * platform device is usually a dual-role USB controller device.
4882 	 */
4883 	if (udev->bus->controller->driver)
4884 		driver_name = udev->bus->controller->driver->name;
4885 	else
4886 		driver_name = udev->bus->sysdev->driver->name;
4887 
4888 	if (udev->speed < USB_SPEED_SUPER)
4889 		dev_info(&udev->dev,
4890 				"%s %s USB device number %d using %s\n",
4891 				(initial ? "new" : "reset"), speed,
4892 				devnum, driver_name);
4893 
4894 	if (initial) {
4895 		/* Set up TT records, if needed  */
4896 		if (hdev->tt) {
4897 			udev->tt = hdev->tt;
4898 			udev->ttport = hdev->ttport;
4899 		} else if (udev->speed != USB_SPEED_HIGH
4900 				&& hdev->speed == USB_SPEED_HIGH) {
4901 			if (!hub->tt.hub) {
4902 				dev_err(&udev->dev, "parent hub has no TT\n");
4903 				retval = -EINVAL;
4904 				goto fail;
4905 			}
4906 			udev->tt = &hub->tt;
4907 			udev->ttport = port1;
4908 		}
4909 	}
4910 
4911 	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
4912 	 * Because device hardware and firmware is sometimes buggy in
4913 	 * this area, and this is how Linux has done it for ages.
4914 	 * Change it cautiously.
4915 	 *
4916 	 * NOTE:  If use_new_scheme() is true we will start by issuing
4917 	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
4918 	 * so it may help with some non-standards-compliant devices.
4919 	 * Otherwise we start with SET_ADDRESS and then try to read the
4920 	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
4921 	 * value.
4922 	 */
4923 	do_new_scheme = use_new_scheme(udev, retry_counter, port_dev);
4924 
4925 	for (retries = 0; retries < GET_DESCRIPTOR_TRIES; (++retries, msleep(100))) {
4926 		if (hub_port_stop_enumerate(hub, port1, retries)) {
4927 			retval = -ENODEV;
4928 			break;
4929 		}
4930 
4931 		if (do_new_scheme) {
4932 			retval = hub_enable_device(udev);
4933 			if (retval < 0) {
4934 				dev_err(&udev->dev,
4935 					"hub failed to enable device, error %d\n",
4936 					retval);
4937 				goto fail;
4938 			}
4939 
4940 			maxp0 = get_bMaxPacketSize0(udev, buf,
4941 					GET_DESCRIPTOR_BUFSIZE, retries == 0);
4942 			if (maxp0 > 0 && !initial &&
4943 					maxp0 != udev->descriptor.bMaxPacketSize0) {
4944 				dev_err(&udev->dev, "device reset changed ep0 maxpacket size!\n");
4945 				retval = -ENODEV;
4946 				goto fail;
4947 			}
4948 
4949 			retval = hub_port_reset(hub, port1, udev, delay, false);
4950 			if (retval < 0)		/* error or disconnect */
4951 				goto fail;
4952 			if (oldspeed != udev->speed) {
4953 				dev_dbg(&udev->dev,
4954 					"device reset changed speed!\n");
4955 				retval = -ENODEV;
4956 				goto fail;
4957 			}
4958 			if (maxp0 < 0) {
4959 				if (maxp0 != -ENODEV)
4960 					dev_err(&udev->dev, "device descriptor read/64, error %d\n",
4961 							maxp0);
4962 				retval = maxp0;
4963 				continue;
4964 			}
4965 		}
4966 
4967 		for (operations = 0; operations < SET_ADDRESS_TRIES; ++operations) {
4968 			retval = hub_set_address(udev, devnum);
4969 			if (retval >= 0)
4970 				break;
4971 			msleep(200);
4972 		}
4973 		if (retval < 0) {
4974 			if (retval != -ENODEV)
4975 				dev_err(&udev->dev, "device not accepting address %d, error %d\n",
4976 						devnum, retval);
4977 			goto fail;
4978 		}
4979 		if (udev->speed >= USB_SPEED_SUPER) {
4980 			devnum = udev->devnum;
4981 			dev_info(&udev->dev,
4982 					"%s SuperSpeed%s%s USB device number %d using %s\n",
4983 					(udev->config) ? "reset" : "new",
4984 				 (udev->speed == USB_SPEED_SUPER_PLUS) ?
4985 						" Plus" : "",
4986 				 (udev->ssp_rate == USB_SSP_GEN_2x2) ?
4987 						" Gen 2x2" :
4988 				 (udev->ssp_rate == USB_SSP_GEN_2x1) ?
4989 						" Gen 2x1" :
4990 				 (udev->ssp_rate == USB_SSP_GEN_1x2) ?
4991 						" Gen 1x2" : "",
4992 				 devnum, driver_name);
4993 		}
4994 
4995 		/*
4996 		 * cope with hardware quirkiness:
4997 		 *  - let SET_ADDRESS settle, some device hardware wants it
4998 		 *  - read ep0 maxpacket even for high and low speed,
4999 		 */
5000 		msleep(10);
5001 
5002 		if (do_new_scheme)
5003 			break;
5004 
5005 		maxp0 = get_bMaxPacketSize0(udev, buf, 8, retries == 0);
5006 		if (maxp0 < 0) {
5007 			retval = maxp0;
5008 			if (retval != -ENODEV)
5009 				dev_err(&udev->dev,
5010 					"device descriptor read/8, error %d\n",
5011 					retval);
5012 		} else {
5013 			u32 delay;
5014 
5015 			if (!initial && maxp0 != udev->descriptor.bMaxPacketSize0) {
5016 				dev_err(&udev->dev, "device reset changed ep0 maxpacket size!\n");
5017 				retval = -ENODEV;
5018 				goto fail;
5019 			}
5020 
5021 			delay = udev->parent->hub_delay;
5022 			udev->hub_delay = min_t(u32, delay,
5023 						USB_TP_TRANSMISSION_DELAY_MAX);
5024 			retval = usb_set_isoch_delay(udev);
5025 			if (retval) {
5026 				dev_dbg(&udev->dev,
5027 					"Failed set isoch delay, error %d\n",
5028 					retval);
5029 				retval = 0;
5030 			}
5031 			break;
5032 		}
5033 	}
5034 	if (retval)
5035 		goto fail;
5036 
5037 	/*
5038 	 * Check the ep0 maxpacket guess and correct it if necessary.
5039 	 * maxp0 is the value stored in the device descriptor;
5040 	 * i is the value it encodes (logarithmic for SuperSpeed or greater).
5041 	 */
5042 	i = maxp0;
5043 	if (udev->speed >= USB_SPEED_SUPER) {
5044 		if (maxp0 <= 16)
5045 			i = 1 << maxp0;
5046 		else
5047 			i = 0;		/* Invalid */
5048 	}
5049 	if (usb_endpoint_maxp(&udev->ep0.desc) == i) {
5050 		;	/* Initial ep0 maxpacket guess is right */
5051 	} else if ((udev->speed == USB_SPEED_FULL ||
5052 				udev->speed == USB_SPEED_HIGH) &&
5053 			(i == 8 || i == 16 || i == 32 || i == 64)) {
5054 		/* Initial guess is wrong; use the descriptor's value */
5055 		if (udev->speed == USB_SPEED_FULL)
5056 			dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
5057 		else
5058 			dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
5059 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
5060 		usb_ep0_reinit(udev);
5061 	} else {
5062 		/* Initial guess is wrong and descriptor's value is invalid */
5063 		dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", maxp0);
5064 		retval = -EMSGSIZE;
5065 		goto fail;
5066 	}
5067 
5068 	descr = usb_get_device_descriptor(udev);
5069 	if (IS_ERR(descr)) {
5070 		retval = PTR_ERR(descr);
5071 		if (retval != -ENODEV)
5072 			dev_err(&udev->dev, "device descriptor read/all, error %d\n",
5073 					retval);
5074 		goto fail;
5075 	}
5076 	if (initial)
5077 		udev->descriptor = *descr;
5078 	else
5079 		*dev_descr = *descr;
5080 	kfree(descr);
5081 
5082 	/*
5083 	 * Some superspeed devices have finished the link training process
5084 	 * and attached to a superspeed hub port, but the device descriptor
5085 	 * got from those devices show they aren't superspeed devices. Warm
5086 	 * reset the port attached by the devices can fix them.
5087 	 */
5088 	if ((udev->speed >= USB_SPEED_SUPER) &&
5089 			(le16_to_cpu(udev->descriptor.bcdUSB) < 0x0300)) {
5090 		dev_err(&udev->dev, "got a wrong device descriptor, warm reset device\n");
5091 		hub_port_reset(hub, port1, udev, HUB_BH_RESET_TIME, true);
5092 		retval = -EINVAL;
5093 		goto fail;
5094 	}
5095 
5096 	usb_detect_quirks(udev);
5097 
5098 	if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) {
5099 		retval = usb_get_bos_descriptor(udev);
5100 		if (!retval) {
5101 			udev->lpm_capable = usb_device_supports_lpm(udev);
5102 			udev->lpm_disable_count = 1;
5103 			usb_set_lpm_parameters(udev);
5104 			usb_req_set_sel(udev);
5105 		}
5106 	}
5107 
5108 	retval = 0;
5109 	/* notify HCD that we have a device connected and addressed */
5110 	if (hcd->driver->update_device)
5111 		hcd->driver->update_device(hcd, udev);
5112 	hub_set_initial_usb2_lpm_policy(udev);
5113 fail:
5114 	if (retval) {
5115 		hub_port_disable(hub, port1, 0);
5116 		update_devnum(udev, devnum);	/* for disconnect processing */
5117 	}
5118 	kfree(buf);
5119 	return retval;
5120 }
5121 
5122 static void
check_highspeed(struct usb_hub * hub,struct usb_device * udev,int port1)5123 check_highspeed(struct usb_hub *hub, struct usb_device *udev, int port1)
5124 {
5125 	struct usb_qualifier_descriptor	*qual;
5126 	int				status;
5127 
5128 	if (udev->quirks & USB_QUIRK_DEVICE_QUALIFIER)
5129 		return;
5130 
5131 	qual = kmalloc(sizeof *qual, GFP_KERNEL);
5132 	if (qual == NULL)
5133 		return;
5134 
5135 	status = usb_get_descriptor(udev, USB_DT_DEVICE_QUALIFIER, 0,
5136 			qual, sizeof *qual);
5137 	if (status == sizeof *qual) {
5138 		dev_info(&udev->dev, "not running at top speed; "
5139 			"connect to a high speed hub\n");
5140 		/* hub LEDs are probably harder to miss than syslog */
5141 		if (hub->has_indicators) {
5142 			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
5143 			queue_delayed_work(system_power_efficient_wq,
5144 					&hub->leds, 0);
5145 		}
5146 	}
5147 	kfree(qual);
5148 }
5149 
5150 static unsigned
hub_power_remaining(struct usb_hub * hub)5151 hub_power_remaining(struct usb_hub *hub)
5152 {
5153 	struct usb_device *hdev = hub->hdev;
5154 	int remaining;
5155 	int port1;
5156 
5157 	if (!hub->limited_power)
5158 		return 0;
5159 
5160 	remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
5161 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
5162 		struct usb_port *port_dev = hub->ports[port1 - 1];
5163 		struct usb_device *udev = port_dev->child;
5164 		unsigned unit_load;
5165 		int delta;
5166 
5167 		if (!udev)
5168 			continue;
5169 		if (hub_is_superspeed(udev))
5170 			unit_load = 150;
5171 		else
5172 			unit_load = 100;
5173 
5174 		/*
5175 		 * Unconfigured devices may not use more than one unit load,
5176 		 * or 8mA for OTG ports
5177 		 */
5178 		if (udev->actconfig)
5179 			delta = usb_get_max_power(udev, udev->actconfig);
5180 		else if (port1 != udev->bus->otg_port || hdev->parent)
5181 			delta = unit_load;
5182 		else
5183 			delta = 8;
5184 		if (delta > hub->mA_per_port)
5185 			dev_warn(&port_dev->dev, "%dmA is over %umA budget!\n",
5186 					delta, hub->mA_per_port);
5187 		remaining -= delta;
5188 	}
5189 	if (remaining < 0) {
5190 		dev_warn(hub->intfdev, "%dmA over power budget!\n",
5191 			-remaining);
5192 		remaining = 0;
5193 	}
5194 	return remaining;
5195 }
5196 
5197 
descriptors_changed(struct usb_device * udev,struct usb_device_descriptor * new_device_descriptor,struct usb_host_bos * old_bos)5198 static int descriptors_changed(struct usb_device *udev,
5199 		struct usb_device_descriptor *new_device_descriptor,
5200 		struct usb_host_bos *old_bos)
5201 {
5202 	int		changed = 0;
5203 	unsigned	index;
5204 	unsigned	serial_len = 0;
5205 	unsigned	len;
5206 	unsigned	old_length;
5207 	int		length;
5208 	char		*buf;
5209 
5210 	if (memcmp(&udev->descriptor, new_device_descriptor,
5211 			sizeof(*new_device_descriptor)) != 0)
5212 		return 1;
5213 
5214 	if ((old_bos && !udev->bos) || (!old_bos && udev->bos))
5215 		return 1;
5216 	if (udev->bos) {
5217 		len = le16_to_cpu(udev->bos->desc->wTotalLength);
5218 		if (len != le16_to_cpu(old_bos->desc->wTotalLength))
5219 			return 1;
5220 		if (memcmp(udev->bos->desc, old_bos->desc, len))
5221 			return 1;
5222 	}
5223 
5224 	/* Since the idVendor, idProduct, and bcdDevice values in the
5225 	 * device descriptor haven't changed, we will assume the
5226 	 * Manufacturer and Product strings haven't changed either.
5227 	 * But the SerialNumber string could be different (e.g., a
5228 	 * different flash card of the same brand).
5229 	 */
5230 	if (udev->serial)
5231 		serial_len = strlen(udev->serial) + 1;
5232 
5233 	len = serial_len;
5234 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
5235 		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
5236 		len = max(len, old_length);
5237 	}
5238 
5239 	buf = kmalloc(len, GFP_NOIO);
5240 	if (!buf)
5241 		/* assume the worst */
5242 		return 1;
5243 
5244 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
5245 		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
5246 		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
5247 				old_length);
5248 		if (length != old_length) {
5249 			dev_dbg(&udev->dev, "config index %d, error %d\n",
5250 					index, length);
5251 			changed = 1;
5252 			break;
5253 		}
5254 		if (memcmp(buf, udev->rawdescriptors[index], old_length)
5255 				!= 0) {
5256 			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
5257 				index,
5258 				((struct usb_config_descriptor *) buf)->
5259 					bConfigurationValue);
5260 			changed = 1;
5261 			break;
5262 		}
5263 	}
5264 
5265 	if (!changed && serial_len) {
5266 		length = usb_string(udev, udev->descriptor.iSerialNumber,
5267 				buf, serial_len);
5268 		if (length + 1 != serial_len) {
5269 			dev_dbg(&udev->dev, "serial string error %d\n",
5270 					length);
5271 			changed = 1;
5272 		} else if (memcmp(buf, udev->serial, length) != 0) {
5273 			dev_dbg(&udev->dev, "serial string changed\n");
5274 			changed = 1;
5275 		}
5276 	}
5277 
5278 	kfree(buf);
5279 	return changed;
5280 }
5281 
hub_port_connect(struct usb_hub * hub,int port1,u16 portstatus,u16 portchange)5282 static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
5283 		u16 portchange)
5284 {
5285 	int status = -ENODEV;
5286 	int i;
5287 	unsigned unit_load;
5288 	struct usb_device *hdev = hub->hdev;
5289 	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
5290 	struct usb_port *port_dev = hub->ports[port1 - 1];
5291 	struct usb_device *udev = port_dev->child;
5292 	static int unreliable_port = -1;
5293 	bool retry_locked;
5294 
5295 	/* Disconnect any existing devices under this port */
5296 	if (udev) {
5297 		if (hcd->usb_phy && !hdev->parent)
5298 			usb_phy_notify_disconnect(hcd->usb_phy, udev->speed);
5299 		usb_disconnect(&port_dev->child);
5300 	}
5301 
5302 	/* We can forget about a "removed" device when there's a physical
5303 	 * disconnect or the connect status changes.
5304 	 */
5305 	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
5306 			(portchange & USB_PORT_STAT_C_CONNECTION))
5307 		clear_bit(port1, hub->removed_bits);
5308 
5309 	if (portchange & (USB_PORT_STAT_C_CONNECTION |
5310 				USB_PORT_STAT_C_ENABLE)) {
5311 		status = hub_port_debounce_be_stable(hub, port1);
5312 		if (status < 0) {
5313 			if (status != -ENODEV &&
5314 				port1 != unreliable_port &&
5315 				printk_ratelimit())
5316 				dev_err(&port_dev->dev, "connect-debounce failed\n");
5317 			portstatus &= ~USB_PORT_STAT_CONNECTION;
5318 			unreliable_port = port1;
5319 		} else {
5320 			portstatus = status;
5321 		}
5322 	}
5323 
5324 	/* Return now if debouncing failed or nothing is connected or
5325 	 * the device was "removed".
5326 	 */
5327 	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
5328 			test_bit(port1, hub->removed_bits)) {
5329 
5330 		/*
5331 		 * maybe switch power back on (e.g. root hub was reset)
5332 		 * but only if the port isn't owned by someone else.
5333 		 */
5334 		if (hub_is_port_power_switchable(hub)
5335 				&& !usb_port_is_power_on(hub, portstatus)
5336 				&& !port_dev->port_owner)
5337 			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
5338 
5339 		if (portstatus & USB_PORT_STAT_ENABLE)
5340 			goto done;
5341 		return;
5342 	}
5343 	if (hub_is_superspeed(hub->hdev))
5344 		unit_load = 150;
5345 	else
5346 		unit_load = 100;
5347 
5348 	status = 0;
5349 
5350 	for (i = 0; i < PORT_INIT_TRIES; i++) {
5351 		if (hub_port_stop_enumerate(hub, port1, i)) {
5352 			status = -ENODEV;
5353 			break;
5354 		}
5355 
5356 		usb_lock_port(port_dev);
5357 		mutex_lock(hcd->address0_mutex);
5358 		retry_locked = true;
5359 		/* reallocate for each attempt, since references
5360 		 * to the previous one can escape in various ways
5361 		 */
5362 		udev = usb_alloc_dev(hdev, hdev->bus, port1);
5363 		if (!udev) {
5364 			dev_err(&port_dev->dev,
5365 					"couldn't allocate usb_device\n");
5366 			mutex_unlock(hcd->address0_mutex);
5367 			usb_unlock_port(port_dev);
5368 			goto done;
5369 		}
5370 
5371 		usb_set_device_state(udev, USB_STATE_POWERED);
5372 		udev->bus_mA = hub->mA_per_port;
5373 		udev->level = hdev->level + 1;
5374 
5375 		/* Devices connected to SuperSpeed hubs are USB 3.0 or later */
5376 		if (hub_is_superspeed(hub->hdev))
5377 			udev->speed = USB_SPEED_SUPER;
5378 		else
5379 			udev->speed = USB_SPEED_UNKNOWN;
5380 
5381 		choose_devnum(udev);
5382 		if (udev->devnum <= 0) {
5383 			status = -ENOTCONN;	/* Don't retry */
5384 			goto loop;
5385 		}
5386 
5387 		/* reset (non-USB 3.0 devices) and get descriptor */
5388 		status = hub_port_init(hub, udev, port1, i, NULL);
5389 		if (status < 0)
5390 			goto loop;
5391 
5392 		mutex_unlock(hcd->address0_mutex);
5393 		usb_unlock_port(port_dev);
5394 		retry_locked = false;
5395 
5396 		if (udev->quirks & USB_QUIRK_DELAY_INIT)
5397 			msleep(2000);
5398 
5399 		/* consecutive bus-powered hubs aren't reliable; they can
5400 		 * violate the voltage drop budget.  if the new child has
5401 		 * a "powered" LED, users should notice we didn't enable it
5402 		 * (without reading syslog), even without per-port LEDs
5403 		 * on the parent.
5404 		 */
5405 		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
5406 				&& udev->bus_mA <= unit_load) {
5407 			u16	devstat;
5408 
5409 			status = usb_get_std_status(udev, USB_RECIP_DEVICE, 0,
5410 					&devstat);
5411 			if (status) {
5412 				dev_dbg(&udev->dev, "get status %d ?\n", status);
5413 				goto loop_disable;
5414 			}
5415 			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
5416 				dev_err(&udev->dev,
5417 					"can't connect bus-powered hub "
5418 					"to this port\n");
5419 				if (hub->has_indicators) {
5420 					hub->indicator[port1-1] =
5421 						INDICATOR_AMBER_BLINK;
5422 					queue_delayed_work(
5423 						system_power_efficient_wq,
5424 						&hub->leds, 0);
5425 				}
5426 				status = -ENOTCONN;	/* Don't retry */
5427 				goto loop_disable;
5428 			}
5429 		}
5430 
5431 		/* check for devices running slower than they could */
5432 		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
5433 				&& udev->speed == USB_SPEED_FULL
5434 				&& highspeed_hubs != 0)
5435 			check_highspeed(hub, udev, port1);
5436 
5437 		/* Store the parent's children[] pointer.  At this point
5438 		 * udev becomes globally accessible, although presumably
5439 		 * no one will look at it until hdev is unlocked.
5440 		 */
5441 		status = 0;
5442 
5443 		mutex_lock(&usb_port_peer_mutex);
5444 
5445 		/* We mustn't add new devices if the parent hub has
5446 		 * been disconnected; we would race with the
5447 		 * recursively_mark_NOTATTACHED() routine.
5448 		 */
5449 		spin_lock_irq(&device_state_lock);
5450 		if (hdev->state == USB_STATE_NOTATTACHED)
5451 			status = -ENOTCONN;
5452 		else
5453 			port_dev->child = udev;
5454 		spin_unlock_irq(&device_state_lock);
5455 		mutex_unlock(&usb_port_peer_mutex);
5456 
5457 		/* Run it through the hoops (find a driver, etc) */
5458 		if (!status) {
5459 			status = usb_new_device(udev);
5460 			if (status) {
5461 				mutex_lock(&usb_port_peer_mutex);
5462 				spin_lock_irq(&device_state_lock);
5463 				port_dev->child = NULL;
5464 				spin_unlock_irq(&device_state_lock);
5465 				mutex_unlock(&usb_port_peer_mutex);
5466 			} else {
5467 				if (hcd->usb_phy && !hdev->parent)
5468 					usb_phy_notify_connect(hcd->usb_phy,
5469 							udev->speed);
5470 			}
5471 		}
5472 
5473 		if (status)
5474 			goto loop_disable;
5475 
5476 		status = hub_power_remaining(hub);
5477 		if (status)
5478 			dev_dbg(hub->intfdev, "%dmA power budget left\n", status);
5479 
5480 		return;
5481 
5482 loop_disable:
5483 		hub_port_disable(hub, port1, 1);
5484 loop:
5485 		usb_ep0_reinit(udev);
5486 		release_devnum(udev);
5487 		hub_free_dev(udev);
5488 		if (retry_locked) {
5489 			mutex_unlock(hcd->address0_mutex);
5490 			usb_unlock_port(port_dev);
5491 		}
5492 		usb_put_dev(udev);
5493 		if ((status == -ENOTCONN) || (status == -ENOTSUPP))
5494 			break;
5495 
5496 		/* When halfway through our retry count, power-cycle the port */
5497 		if (i == (PORT_INIT_TRIES - 1) / 2) {
5498 			dev_info(&port_dev->dev, "attempt power cycle\n");
5499 			usb_hub_set_port_power(hdev, hub, port1, false);
5500 			msleep(2 * hub_power_on_good_delay(hub));
5501 			usb_hub_set_port_power(hdev, hub, port1, true);
5502 			msleep(hub_power_on_good_delay(hub));
5503 		}
5504 	}
5505 	if (hub->hdev->parent ||
5506 			!hcd->driver->port_handed_over ||
5507 			!(hcd->driver->port_handed_over)(hcd, port1)) {
5508 		if (status != -ENOTCONN && status != -ENODEV)
5509 			dev_err(&port_dev->dev,
5510 					"unable to enumerate USB device\n");
5511 	}
5512 
5513 done:
5514 	hub_port_disable(hub, port1, 1);
5515 	if (hcd->driver->relinquish_port && !hub->hdev->parent) {
5516 		if (status != -ENOTCONN && status != -ENODEV)
5517 			hcd->driver->relinquish_port(hcd, port1);
5518 	}
5519 }
5520 
5521 /* Handle physical or logical connection change events.
5522  * This routine is called when:
5523  *	a port connection-change occurs;
5524  *	a port enable-change occurs (often caused by EMI);
5525  *	usb_reset_and_verify_device() encounters changed descriptors (as from
5526  *		a firmware download)
5527  * caller already locked the hub
5528  */
hub_port_connect_change(struct usb_hub * hub,int port1,u16 portstatus,u16 portchange)5529 static void hub_port_connect_change(struct usb_hub *hub, int port1,
5530 					u16 portstatus, u16 portchange)
5531 		__must_hold(&port_dev->status_lock)
5532 {
5533 	struct usb_port *port_dev = hub->ports[port1 - 1];
5534 	struct usb_device *udev = port_dev->child;
5535 	struct usb_device_descriptor *descr;
5536 	int status = -ENODEV;
5537 
5538 	dev_dbg(&port_dev->dev, "status %04x, change %04x, %s\n", portstatus,
5539 			portchange, portspeed(hub, portstatus));
5540 
5541 	if (hub->has_indicators) {
5542 		set_port_led(hub, port1, HUB_LED_AUTO);
5543 		hub->indicator[port1-1] = INDICATOR_AUTO;
5544 	}
5545 
5546 #ifdef	CONFIG_USB_OTG
5547 	/* during HNP, don't repeat the debounce */
5548 	if (hub->hdev->bus->is_b_host)
5549 		portchange &= ~(USB_PORT_STAT_C_CONNECTION |
5550 				USB_PORT_STAT_C_ENABLE);
5551 #endif
5552 
5553 	/* Try to resuscitate an existing device */
5554 	if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
5555 			udev->state != USB_STATE_NOTATTACHED) {
5556 		if (portstatus & USB_PORT_STAT_ENABLE) {
5557 			/*
5558 			 * USB-3 connections are initialized automatically by
5559 			 * the hostcontroller hardware. Therefore check for
5560 			 * changed device descriptors before resuscitating the
5561 			 * device.
5562 			 */
5563 			descr = usb_get_device_descriptor(udev);
5564 			if (IS_ERR(descr)) {
5565 				dev_dbg(&udev->dev,
5566 						"can't read device descriptor %ld\n",
5567 						PTR_ERR(descr));
5568 			} else {
5569 				if (descriptors_changed(udev, descr,
5570 						udev->bos)) {
5571 					dev_dbg(&udev->dev,
5572 							"device descriptor has changed\n");
5573 				} else {
5574 					status = 0; /* Nothing to do */
5575 				}
5576 				kfree(descr);
5577 			}
5578 #ifdef CONFIG_PM
5579 		} else if (udev->state == USB_STATE_SUSPENDED &&
5580 				udev->persist_enabled) {
5581 			/* For a suspended device, treat this as a
5582 			 * remote wakeup event.
5583 			 */
5584 			usb_unlock_port(port_dev);
5585 			status = usb_remote_wakeup(udev);
5586 			usb_lock_port(port_dev);
5587 #endif
5588 		} else {
5589 			/* Don't resuscitate */;
5590 		}
5591 	}
5592 	clear_bit(port1, hub->change_bits);
5593 
5594 	/* successfully revalidated the connection */
5595 	if (status == 0)
5596 		return;
5597 
5598 	usb_unlock_port(port_dev);
5599 	hub_port_connect(hub, port1, portstatus, portchange);
5600 	usb_lock_port(port_dev);
5601 }
5602 
5603 /* Handle notifying userspace about hub over-current events */
port_over_current_notify(struct usb_port * port_dev)5604 static void port_over_current_notify(struct usb_port *port_dev)
5605 {
5606 	char *envp[3] = { NULL, NULL, NULL };
5607 	struct device *hub_dev;
5608 	char *port_dev_path;
5609 
5610 	sysfs_notify(&port_dev->dev.kobj, NULL, "over_current_count");
5611 
5612 	hub_dev = port_dev->dev.parent;
5613 
5614 	if (!hub_dev)
5615 		return;
5616 
5617 	port_dev_path = kobject_get_path(&port_dev->dev.kobj, GFP_KERNEL);
5618 	if (!port_dev_path)
5619 		return;
5620 
5621 	envp[0] = kasprintf(GFP_KERNEL, "OVER_CURRENT_PORT=%s", port_dev_path);
5622 	if (!envp[0])
5623 		goto exit;
5624 
5625 	envp[1] = kasprintf(GFP_KERNEL, "OVER_CURRENT_COUNT=%u",
5626 			port_dev->over_current_count);
5627 	if (!envp[1])
5628 		goto exit;
5629 
5630 	kobject_uevent_env(&hub_dev->kobj, KOBJ_CHANGE, envp);
5631 
5632 exit:
5633 	kfree(envp[1]);
5634 	kfree(envp[0]);
5635 	kfree(port_dev_path);
5636 }
5637 
port_event(struct usb_hub * hub,int port1)5638 static void port_event(struct usb_hub *hub, int port1)
5639 		__must_hold(&port_dev->status_lock)
5640 {
5641 	int connect_change;
5642 	struct usb_port *port_dev = hub->ports[port1 - 1];
5643 	struct usb_device *udev = port_dev->child;
5644 	struct usb_device *hdev = hub->hdev;
5645 	u16 portstatus, portchange;
5646 	int i = 0;
5647 
5648 	connect_change = test_bit(port1, hub->change_bits);
5649 	clear_bit(port1, hub->event_bits);
5650 	clear_bit(port1, hub->wakeup_bits);
5651 
5652 	if (usb_hub_port_status(hub, port1, &portstatus, &portchange) < 0)
5653 		return;
5654 
5655 	if (portchange & USB_PORT_STAT_C_CONNECTION) {
5656 		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
5657 		connect_change = 1;
5658 	}
5659 
5660 	if (portchange & USB_PORT_STAT_C_ENABLE) {
5661 		if (!connect_change)
5662 			dev_dbg(&port_dev->dev, "enable change, status %08x\n",
5663 					portstatus);
5664 		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
5665 
5666 		/*
5667 		 * EM interference sometimes causes badly shielded USB devices
5668 		 * to be shutdown by the hub, this hack enables them again.
5669 		 * Works at least with mouse driver.
5670 		 */
5671 		if (!(portstatus & USB_PORT_STAT_ENABLE)
5672 		    && !connect_change && udev) {
5673 			dev_err(&port_dev->dev, "disabled by hub (EMI?), re-enabling...\n");
5674 			connect_change = 1;
5675 		}
5676 	}
5677 
5678 	if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
5679 		u16 status = 0, unused;
5680 		port_dev->over_current_count++;
5681 		port_over_current_notify(port_dev);
5682 
5683 		dev_dbg(&port_dev->dev, "over-current change #%u\n",
5684 			port_dev->over_current_count);
5685 		usb_clear_port_feature(hdev, port1,
5686 				USB_PORT_FEAT_C_OVER_CURRENT);
5687 		msleep(100);	/* Cool down */
5688 		hub_power_on(hub, true);
5689 		usb_hub_port_status(hub, port1, &status, &unused);
5690 		if (status & USB_PORT_STAT_OVERCURRENT)
5691 			dev_err(&port_dev->dev, "over-current condition\n");
5692 	}
5693 
5694 	if (portchange & USB_PORT_STAT_C_RESET) {
5695 		dev_dbg(&port_dev->dev, "reset change\n");
5696 		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_RESET);
5697 	}
5698 	if ((portchange & USB_PORT_STAT_C_BH_RESET)
5699 	    && hub_is_superspeed(hdev)) {
5700 		dev_dbg(&port_dev->dev, "warm reset change\n");
5701 		usb_clear_port_feature(hdev, port1,
5702 				USB_PORT_FEAT_C_BH_PORT_RESET);
5703 	}
5704 	if (portchange & USB_PORT_STAT_C_LINK_STATE) {
5705 		dev_dbg(&port_dev->dev, "link state change\n");
5706 		usb_clear_port_feature(hdev, port1,
5707 				USB_PORT_FEAT_C_PORT_LINK_STATE);
5708 	}
5709 	if (portchange & USB_PORT_STAT_C_CONFIG_ERROR) {
5710 		dev_warn(&port_dev->dev, "config error\n");
5711 		usb_clear_port_feature(hdev, port1,
5712 				USB_PORT_FEAT_C_PORT_CONFIG_ERROR);
5713 	}
5714 
5715 	/* skip port actions that require the port to be powered on */
5716 	if (!pm_runtime_active(&port_dev->dev))
5717 		return;
5718 
5719 	/* skip port actions if ignore_event and early_stop are true */
5720 	if (port_dev->ignore_event && port_dev->early_stop)
5721 		return;
5722 
5723 	if (hub_handle_remote_wakeup(hub, port1, portstatus, portchange))
5724 		connect_change = 1;
5725 
5726 	/*
5727 	 * Avoid trying to recover a USB3 SS.Inactive port with a warm reset if
5728 	 * the device was disconnected. A 12ms disconnect detect timer in
5729 	 * SS.Inactive state transitions the port to RxDetect automatically.
5730 	 * SS.Inactive link error state is common during device disconnect.
5731 	 */
5732 	while (hub_port_warm_reset_required(hub, port1, portstatus)) {
5733 		if ((i++ < DETECT_DISCONNECT_TRIES) && udev) {
5734 			u16 unused;
5735 
5736 			msleep(20);
5737 			usb_hub_port_status(hub, port1, &portstatus, &unused);
5738 			dev_dbg(&port_dev->dev, "Wait for inactive link disconnect detect\n");
5739 			continue;
5740 		} else if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
5741 				|| udev->state == USB_STATE_NOTATTACHED) {
5742 			dev_dbg(&port_dev->dev, "do warm reset, port only\n");
5743 			if (hub_port_reset(hub, port1, NULL,
5744 					HUB_BH_RESET_TIME, true) < 0)
5745 				hub_port_disable(hub, port1, 1);
5746 		} else {
5747 			dev_dbg(&port_dev->dev, "do warm reset, full device\n");
5748 			usb_unlock_port(port_dev);
5749 			usb_lock_device(udev);
5750 			usb_reset_device(udev);
5751 			usb_unlock_device(udev);
5752 			usb_lock_port(port_dev);
5753 			connect_change = 0;
5754 		}
5755 		break;
5756 	}
5757 
5758 	if (connect_change)
5759 		hub_port_connect_change(hub, port1, portstatus, portchange);
5760 }
5761 
hub_event(struct work_struct * work)5762 static void hub_event(struct work_struct *work)
5763 {
5764 	struct usb_device *hdev;
5765 	struct usb_interface *intf;
5766 	struct usb_hub *hub;
5767 	struct device *hub_dev;
5768 	u16 hubstatus;
5769 	u16 hubchange;
5770 	int i, ret;
5771 
5772 	hub = container_of(work, struct usb_hub, events);
5773 	hdev = hub->hdev;
5774 	hub_dev = hub->intfdev;
5775 	intf = to_usb_interface(hub_dev);
5776 
5777 	kcov_remote_start_usb((u64)hdev->bus->busnum);
5778 
5779 	dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
5780 			hdev->state, hdev->maxchild,
5781 			/* NOTE: expects max 15 ports... */
5782 			(u16) hub->change_bits[0],
5783 			(u16) hub->event_bits[0]);
5784 
5785 	/* Lock the device, then check to see if we were
5786 	 * disconnected while waiting for the lock to succeed. */
5787 	usb_lock_device(hdev);
5788 	if (unlikely(hub->disconnected))
5789 		goto out_hdev_lock;
5790 
5791 	/* If the hub has died, clean up after it */
5792 	if (hdev->state == USB_STATE_NOTATTACHED) {
5793 		hub->error = -ENODEV;
5794 		hub_quiesce(hub, HUB_DISCONNECT);
5795 		goto out_hdev_lock;
5796 	}
5797 
5798 	/* Autoresume */
5799 	ret = usb_autopm_get_interface(intf);
5800 	if (ret) {
5801 		dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
5802 		goto out_hdev_lock;
5803 	}
5804 
5805 	/* If this is an inactive hub, do nothing */
5806 	if (hub->quiescing)
5807 		goto out_autopm;
5808 
5809 	if (hub->error) {
5810 		dev_dbg(hub_dev, "resetting for error %d\n", hub->error);
5811 
5812 		ret = usb_reset_device(hdev);
5813 		if (ret) {
5814 			dev_dbg(hub_dev, "error resetting hub: %d\n", ret);
5815 			goto out_autopm;
5816 		}
5817 
5818 		hub->nerrors = 0;
5819 		hub->error = 0;
5820 	}
5821 
5822 	/* deal with port status changes */
5823 	for (i = 1; i <= hdev->maxchild; i++) {
5824 		struct usb_port *port_dev = hub->ports[i - 1];
5825 
5826 		if (test_bit(i, hub->event_bits)
5827 				|| test_bit(i, hub->change_bits)
5828 				|| test_bit(i, hub->wakeup_bits)) {
5829 			/*
5830 			 * The get_noresume and barrier ensure that if
5831 			 * the port was in the process of resuming, we
5832 			 * flush that work and keep the port active for
5833 			 * the duration of the port_event().  However,
5834 			 * if the port is runtime pm suspended
5835 			 * (powered-off), we leave it in that state, run
5836 			 * an abbreviated port_event(), and move on.
5837 			 */
5838 			pm_runtime_get_noresume(&port_dev->dev);
5839 			pm_runtime_barrier(&port_dev->dev);
5840 			usb_lock_port(port_dev);
5841 			port_event(hub, i);
5842 			usb_unlock_port(port_dev);
5843 			pm_runtime_put_sync(&port_dev->dev);
5844 		}
5845 	}
5846 
5847 	/* deal with hub status changes */
5848 	if (test_and_clear_bit(0, hub->event_bits) == 0)
5849 		;	/* do nothing */
5850 	else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
5851 		dev_err(hub_dev, "get_hub_status failed\n");
5852 	else {
5853 		if (hubchange & HUB_CHANGE_LOCAL_POWER) {
5854 			dev_dbg(hub_dev, "power change\n");
5855 			clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
5856 			if (hubstatus & HUB_STATUS_LOCAL_POWER)
5857 				/* FIXME: Is this always true? */
5858 				hub->limited_power = 1;
5859 			else
5860 				hub->limited_power = 0;
5861 		}
5862 		if (hubchange & HUB_CHANGE_OVERCURRENT) {
5863 			u16 status = 0;
5864 			u16 unused;
5865 
5866 			dev_dbg(hub_dev, "over-current change\n");
5867 			clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
5868 			msleep(500);	/* Cool down */
5869 			hub_power_on(hub, true);
5870 			hub_hub_status(hub, &status, &unused);
5871 			if (status & HUB_STATUS_OVERCURRENT)
5872 				dev_err(hub_dev, "over-current condition\n");
5873 		}
5874 	}
5875 
5876 out_autopm:
5877 	/* Balance the usb_autopm_get_interface() above */
5878 	usb_autopm_put_interface_no_suspend(intf);
5879 out_hdev_lock:
5880 	usb_unlock_device(hdev);
5881 
5882 	/* Balance the stuff in kick_hub_wq() and allow autosuspend */
5883 	usb_autopm_put_interface(intf);
5884 	kref_put(&hub->kref, hub_release);
5885 
5886 	kcov_remote_stop();
5887 }
5888 
5889 static const struct usb_device_id hub_id_table[] = {
5890     { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5891                    | USB_DEVICE_ID_MATCH_PRODUCT
5892                    | USB_DEVICE_ID_MATCH_INT_CLASS,
5893       .idVendor = USB_VENDOR_SMSC,
5894       .idProduct = USB_PRODUCT_USB5534B,
5895       .bInterfaceClass = USB_CLASS_HUB,
5896       .driver_info = HUB_QUIRK_DISABLE_AUTOSUSPEND},
5897     { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5898                    | USB_DEVICE_ID_MATCH_PRODUCT,
5899       .idVendor = USB_VENDOR_CYPRESS,
5900       .idProduct = USB_PRODUCT_CY7C65632,
5901       .driver_info = HUB_QUIRK_DISABLE_AUTOSUSPEND},
5902     { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5903 			| USB_DEVICE_ID_MATCH_INT_CLASS,
5904       .idVendor = USB_VENDOR_GENESYS_LOGIC,
5905       .bInterfaceClass = USB_CLASS_HUB,
5906       .driver_info = HUB_QUIRK_CHECK_PORT_AUTOSUSPEND},
5907     { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5908 			| USB_DEVICE_ID_MATCH_PRODUCT,
5909       .idVendor = USB_VENDOR_TEXAS_INSTRUMENTS,
5910       .idProduct = USB_PRODUCT_TUSB8041_USB2,
5911       .driver_info = HUB_QUIRK_DISABLE_AUTOSUSPEND},
5912     { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5913 			| USB_DEVICE_ID_MATCH_PRODUCT,
5914       .idVendor = USB_VENDOR_TEXAS_INSTRUMENTS,
5915       .idProduct = USB_PRODUCT_TUSB8041_USB3,
5916       .driver_info = HUB_QUIRK_DISABLE_AUTOSUSPEND},
5917     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
5918       .bDeviceClass = USB_CLASS_HUB},
5919     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
5920       .bInterfaceClass = USB_CLASS_HUB},
5921     { }						/* Terminating entry */
5922 };
5923 
5924 MODULE_DEVICE_TABLE(usb, hub_id_table);
5925 
5926 static struct usb_driver hub_driver = {
5927 	.name =		"hub",
5928 	.probe =	hub_probe,
5929 	.disconnect =	hub_disconnect,
5930 	.suspend =	hub_suspend,
5931 	.resume =	hub_resume,
5932 	.reset_resume =	hub_reset_resume,
5933 	.pre_reset =	hub_pre_reset,
5934 	.post_reset =	hub_post_reset,
5935 	.unlocked_ioctl = hub_ioctl,
5936 	.id_table =	hub_id_table,
5937 	.supports_autosuspend =	1,
5938 };
5939 
usb_hub_init(void)5940 int usb_hub_init(void)
5941 {
5942 	if (usb_register(&hub_driver) < 0) {
5943 		printk(KERN_ERR "%s: can't register hub driver\n",
5944 			usbcore_name);
5945 		return -1;
5946 	}
5947 
5948 	/*
5949 	 * The workqueue needs to be freezable to avoid interfering with
5950 	 * USB-PERSIST port handover. Otherwise it might see that a full-speed
5951 	 * device was gone before the EHCI controller had handed its port
5952 	 * over to the companion full-speed controller.
5953 	 */
5954 	hub_wq = alloc_workqueue("usb_hub_wq", WQ_FREEZABLE, 0);
5955 	if (hub_wq)
5956 		return 0;
5957 
5958 	/* Fall through if kernel_thread failed */
5959 	usb_deregister(&hub_driver);
5960 	pr_err("%s: can't allocate workqueue for usb hub\n", usbcore_name);
5961 
5962 	return -1;
5963 }
5964 
usb_hub_cleanup(void)5965 void usb_hub_cleanup(void)
5966 {
5967 	destroy_workqueue(hub_wq);
5968 
5969 	/*
5970 	 * Hub resources are freed for us by usb_deregister. It calls
5971 	 * usb_driver_purge on every device which in turn calls that
5972 	 * devices disconnect function if it is using this driver.
5973 	 * The hub_disconnect function takes care of releasing the
5974 	 * individual hub resources. -greg
5975 	 */
5976 	usb_deregister(&hub_driver);
5977 } /* usb_hub_cleanup() */
5978 
5979 /**
5980  * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
5981  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
5982  *
5983  * WARNING - don't use this routine to reset a composite device
5984  * (one with multiple interfaces owned by separate drivers)!
5985  * Use usb_reset_device() instead.
5986  *
5987  * Do a port reset, reassign the device's address, and establish its
5988  * former operating configuration.  If the reset fails, or the device's
5989  * descriptors change from their values before the reset, or the original
5990  * configuration and altsettings cannot be restored, a flag will be set
5991  * telling hub_wq to pretend the device has been disconnected and then
5992  * re-connected.  All drivers will be unbound, and the device will be
5993  * re-enumerated and probed all over again.
5994  *
5995  * Return: 0 if the reset succeeded, -ENODEV if the device has been
5996  * flagged for logical disconnection, or some other negative error code
5997  * if the reset wasn't even attempted.
5998  *
5999  * Note:
6000  * The caller must own the device lock and the port lock, the latter is
6001  * taken by usb_reset_device().  For example, it's safe to use
6002  * usb_reset_device() from a driver probe() routine after downloading
6003  * new firmware.  For calls that might not occur during probe(), drivers
6004  * should lock the device using usb_lock_device_for_reset().
6005  *
6006  * Locking exception: This routine may also be called from within an
6007  * autoresume handler.  Such usage won't conflict with other tasks
6008  * holding the device lock because these tasks should always call
6009  * usb_autopm_resume_device(), thereby preventing any unwanted
6010  * autoresume.  The autoresume handler is expected to have already
6011  * acquired the port lock before calling this routine.
6012  */
usb_reset_and_verify_device(struct usb_device * udev)6013 static int usb_reset_and_verify_device(struct usb_device *udev)
6014 {
6015 	struct usb_device		*parent_hdev = udev->parent;
6016 	struct usb_hub			*parent_hub;
6017 	struct usb_hcd			*hcd = bus_to_hcd(udev->bus);
6018 	struct usb_device_descriptor	descriptor;
6019 	struct usb_host_bos		*bos;
6020 	int				i, j, ret = 0;
6021 	int				port1 = udev->portnum;
6022 
6023 	if (udev->state == USB_STATE_NOTATTACHED ||
6024 			udev->state == USB_STATE_SUSPENDED) {
6025 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
6026 				udev->state);
6027 		return -EINVAL;
6028 	}
6029 
6030 	if (!parent_hdev)
6031 		return -EISDIR;
6032 
6033 	parent_hub = usb_hub_to_struct_hub(parent_hdev);
6034 
6035 	/* Disable USB2 hardware LPM.
6036 	 * It will be re-enabled by the enumeration process.
6037 	 */
6038 	usb_disable_usb2_hardware_lpm(udev);
6039 
6040 	bos = udev->bos;
6041 	udev->bos = NULL;
6042 
6043 	mutex_lock(hcd->address0_mutex);
6044 
6045 	for (i = 0; i < PORT_INIT_TRIES; ++i) {
6046 		if (hub_port_stop_enumerate(parent_hub, port1, i)) {
6047 			ret = -ENODEV;
6048 			break;
6049 		}
6050 
6051 		/* ep0 maxpacket size may change; let the HCD know about it.
6052 		 * Other endpoints will be handled by re-enumeration. */
6053 		usb_ep0_reinit(udev);
6054 		ret = hub_port_init(parent_hub, udev, port1, i, &descriptor);
6055 		if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
6056 			break;
6057 	}
6058 	mutex_unlock(hcd->address0_mutex);
6059 
6060 	if (ret < 0)
6061 		goto re_enumerate;
6062 
6063 	/* Device might have changed firmware (DFU or similar) */
6064 	if (descriptors_changed(udev, &descriptor, bos)) {
6065 		dev_info(&udev->dev, "device firmware changed\n");
6066 		goto re_enumerate;
6067 	}
6068 
6069 	/* Restore the device's previous configuration */
6070 	if (!udev->actconfig)
6071 		goto done;
6072 
6073 	mutex_lock(hcd->bandwidth_mutex);
6074 	ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL);
6075 	if (ret < 0) {
6076 		dev_warn(&udev->dev,
6077 				"Busted HC?  Not enough HCD resources for "
6078 				"old configuration.\n");
6079 		mutex_unlock(hcd->bandwidth_mutex);
6080 		goto re_enumerate;
6081 	}
6082 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
6083 			USB_REQ_SET_CONFIGURATION, 0,
6084 			udev->actconfig->desc.bConfigurationValue, 0,
6085 			NULL, 0, USB_CTRL_SET_TIMEOUT);
6086 	if (ret < 0) {
6087 		dev_err(&udev->dev,
6088 			"can't restore configuration #%d (error=%d)\n",
6089 			udev->actconfig->desc.bConfigurationValue, ret);
6090 		mutex_unlock(hcd->bandwidth_mutex);
6091 		goto re_enumerate;
6092 	}
6093 	mutex_unlock(hcd->bandwidth_mutex);
6094 	usb_set_device_state(udev, USB_STATE_CONFIGURED);
6095 
6096 	/* Put interfaces back into the same altsettings as before.
6097 	 * Don't bother to send the Set-Interface request for interfaces
6098 	 * that were already in altsetting 0; besides being unnecessary,
6099 	 * many devices can't handle it.  Instead just reset the host-side
6100 	 * endpoint state.
6101 	 */
6102 	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
6103 		struct usb_host_config *config = udev->actconfig;
6104 		struct usb_interface *intf = config->interface[i];
6105 		struct usb_interface_descriptor *desc;
6106 
6107 		desc = &intf->cur_altsetting->desc;
6108 		if (desc->bAlternateSetting == 0) {
6109 			usb_disable_interface(udev, intf, true);
6110 			usb_enable_interface(udev, intf, true);
6111 			ret = 0;
6112 		} else {
6113 			/* Let the bandwidth allocation function know that this
6114 			 * device has been reset, and it will have to use
6115 			 * alternate setting 0 as the current alternate setting.
6116 			 */
6117 			intf->resetting_device = 1;
6118 			ret = usb_set_interface(udev, desc->bInterfaceNumber,
6119 					desc->bAlternateSetting);
6120 			intf->resetting_device = 0;
6121 		}
6122 		if (ret < 0) {
6123 			dev_err(&udev->dev, "failed to restore interface %d "
6124 				"altsetting %d (error=%d)\n",
6125 				desc->bInterfaceNumber,
6126 				desc->bAlternateSetting,
6127 				ret);
6128 			goto re_enumerate;
6129 		}
6130 		/* Resetting also frees any allocated streams */
6131 		for (j = 0; j < intf->cur_altsetting->desc.bNumEndpoints; j++)
6132 			intf->cur_altsetting->endpoint[j].streams = 0;
6133 	}
6134 
6135 done:
6136 	/* Now that the alt settings are re-installed, enable LTM and LPM. */
6137 	usb_enable_usb2_hardware_lpm(udev);
6138 	usb_unlocked_enable_lpm(udev);
6139 	usb_enable_ltm(udev);
6140 	usb_release_bos_descriptor(udev);
6141 	udev->bos = bos;
6142 	return 0;
6143 
6144 re_enumerate:
6145 	usb_release_bos_descriptor(udev);
6146 	udev->bos = bos;
6147 	hub_port_logical_disconnect(parent_hub, port1);
6148 	return -ENODEV;
6149 }
6150 
6151 /**
6152  * usb_reset_device - warn interface drivers and perform a USB port reset
6153  * @udev: device to reset (not in NOTATTACHED state)
6154  *
6155  * Warns all drivers bound to registered interfaces (using their pre_reset
6156  * method), performs the port reset, and then lets the drivers know that
6157  * the reset is over (using their post_reset method).
6158  *
6159  * Return: The same as for usb_reset_and_verify_device().
6160  * However, if a reset is already in progress (for instance, if a
6161  * driver doesn't have pre_reset() or post_reset() callbacks, and while
6162  * being unbound or re-bound during the ongoing reset its disconnect()
6163  * or probe() routine tries to perform a second, nested reset), the
6164  * routine returns -EINPROGRESS.
6165  *
6166  * Note:
6167  * The caller must own the device lock.  For example, it's safe to use
6168  * this from a driver probe() routine after downloading new firmware.
6169  * For calls that might not occur during probe(), drivers should lock
6170  * the device using usb_lock_device_for_reset().
6171  *
6172  * If an interface is currently being probed or disconnected, we assume
6173  * its driver knows how to handle resets.  For all other interfaces,
6174  * if the driver doesn't have pre_reset and post_reset methods then
6175  * we attempt to unbind it and rebind afterward.
6176  */
usb_reset_device(struct usb_device * udev)6177 int usb_reset_device(struct usb_device *udev)
6178 {
6179 	int ret;
6180 	int i;
6181 	unsigned int noio_flag;
6182 	struct usb_port *port_dev;
6183 	struct usb_host_config *config = udev->actconfig;
6184 	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
6185 
6186 	if (udev->state == USB_STATE_NOTATTACHED) {
6187 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
6188 				udev->state);
6189 		return -EINVAL;
6190 	}
6191 
6192 	if (!udev->parent) {
6193 		/* this requires hcd-specific logic; see ohci_restart() */
6194 		dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
6195 		return -EISDIR;
6196 	}
6197 
6198 	if (udev->reset_in_progress)
6199 		return -EINPROGRESS;
6200 	udev->reset_in_progress = 1;
6201 
6202 	port_dev = hub->ports[udev->portnum - 1];
6203 
6204 	/*
6205 	 * Don't allocate memory with GFP_KERNEL in current
6206 	 * context to avoid possible deadlock if usb mass
6207 	 * storage interface or usbnet interface(iSCSI case)
6208 	 * is included in current configuration. The easist
6209 	 * approach is to do it for every device reset,
6210 	 * because the device 'memalloc_noio' flag may have
6211 	 * not been set before reseting the usb device.
6212 	 */
6213 	noio_flag = memalloc_noio_save();
6214 
6215 	/* Prevent autosuspend during the reset */
6216 	usb_autoresume_device(udev);
6217 
6218 	if (config) {
6219 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
6220 			struct usb_interface *cintf = config->interface[i];
6221 			struct usb_driver *drv;
6222 			int unbind = 0;
6223 
6224 			if (cintf->dev.driver) {
6225 				drv = to_usb_driver(cintf->dev.driver);
6226 				if (drv->pre_reset && drv->post_reset)
6227 					unbind = (drv->pre_reset)(cintf);
6228 				else if (cintf->condition ==
6229 						USB_INTERFACE_BOUND)
6230 					unbind = 1;
6231 				if (unbind)
6232 					usb_forced_unbind_intf(cintf);
6233 			}
6234 		}
6235 	}
6236 
6237 	usb_lock_port(port_dev);
6238 	ret = usb_reset_and_verify_device(udev);
6239 	usb_unlock_port(port_dev);
6240 
6241 	if (config) {
6242 		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
6243 			struct usb_interface *cintf = config->interface[i];
6244 			struct usb_driver *drv;
6245 			int rebind = cintf->needs_binding;
6246 
6247 			if (!rebind && cintf->dev.driver) {
6248 				drv = to_usb_driver(cintf->dev.driver);
6249 				if (drv->post_reset)
6250 					rebind = (drv->post_reset)(cintf);
6251 				else if (cintf->condition ==
6252 						USB_INTERFACE_BOUND)
6253 					rebind = 1;
6254 				if (rebind)
6255 					cintf->needs_binding = 1;
6256 			}
6257 		}
6258 
6259 		/* If the reset failed, hub_wq will unbind drivers later */
6260 		if (ret == 0)
6261 			usb_unbind_and_rebind_marked_interfaces(udev);
6262 	}
6263 
6264 	usb_autosuspend_device(udev);
6265 	memalloc_noio_restore(noio_flag);
6266 	udev->reset_in_progress = 0;
6267 	return ret;
6268 }
6269 EXPORT_SYMBOL_GPL(usb_reset_device);
6270 
6271 
6272 /**
6273  * usb_queue_reset_device - Reset a USB device from an atomic context
6274  * @iface: USB interface belonging to the device to reset
6275  *
6276  * This function can be used to reset a USB device from an atomic
6277  * context, where usb_reset_device() won't work (as it blocks).
6278  *
6279  * Doing a reset via this method is functionally equivalent to calling
6280  * usb_reset_device(), except for the fact that it is delayed to a
6281  * workqueue. This means that any drivers bound to other interfaces
6282  * might be unbound, as well as users from usbfs in user space.
6283  *
6284  * Corner cases:
6285  *
6286  * - Scheduling two resets at the same time from two different drivers
6287  *   attached to two different interfaces of the same device is
6288  *   possible; depending on how the driver attached to each interface
6289  *   handles ->pre_reset(), the second reset might happen or not.
6290  *
6291  * - If the reset is delayed so long that the interface is unbound from
6292  *   its driver, the reset will be skipped.
6293  *
6294  * - This function can be called during .probe().  It can also be called
6295  *   during .disconnect(), but doing so is pointless because the reset
6296  *   will not occur.  If you really want to reset the device during
6297  *   .disconnect(), call usb_reset_device() directly -- but watch out
6298  *   for nested unbinding issues!
6299  */
usb_queue_reset_device(struct usb_interface * iface)6300 void usb_queue_reset_device(struct usb_interface *iface)
6301 {
6302 	if (schedule_work(&iface->reset_ws))
6303 		usb_get_intf(iface);
6304 }
6305 EXPORT_SYMBOL_GPL(usb_queue_reset_device);
6306 
6307 /**
6308  * usb_hub_find_child - Get the pointer of child device
6309  * attached to the port which is specified by @port1.
6310  * @hdev: USB device belonging to the usb hub
6311  * @port1: port num to indicate which port the child device
6312  *	is attached to.
6313  *
6314  * USB drivers call this function to get hub's child device
6315  * pointer.
6316  *
6317  * Return: %NULL if input param is invalid and
6318  * child's usb_device pointer if non-NULL.
6319  */
usb_hub_find_child(struct usb_device * hdev,int port1)6320 struct usb_device *usb_hub_find_child(struct usb_device *hdev,
6321 		int port1)
6322 {
6323 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
6324 
6325 	if (port1 < 1 || port1 > hdev->maxchild)
6326 		return NULL;
6327 	return hub->ports[port1 - 1]->child;
6328 }
6329 EXPORT_SYMBOL_GPL(usb_hub_find_child);
6330 
usb_hub_adjust_deviceremovable(struct usb_device * hdev,struct usb_hub_descriptor * desc)6331 void usb_hub_adjust_deviceremovable(struct usb_device *hdev,
6332 		struct usb_hub_descriptor *desc)
6333 {
6334 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
6335 	enum usb_port_connect_type connect_type;
6336 	int i;
6337 
6338 	if (!hub)
6339 		return;
6340 
6341 	if (!hub_is_superspeed(hdev)) {
6342 		for (i = 1; i <= hdev->maxchild; i++) {
6343 			struct usb_port *port_dev = hub->ports[i - 1];
6344 
6345 			connect_type = port_dev->connect_type;
6346 			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
6347 				u8 mask = 1 << (i%8);
6348 
6349 				if (!(desc->u.hs.DeviceRemovable[i/8] & mask)) {
6350 					dev_dbg(&port_dev->dev, "DeviceRemovable is changed to 1 according to platform information.\n");
6351 					desc->u.hs.DeviceRemovable[i/8]	|= mask;
6352 				}
6353 			}
6354 		}
6355 	} else {
6356 		u16 port_removable = le16_to_cpu(desc->u.ss.DeviceRemovable);
6357 
6358 		for (i = 1; i <= hdev->maxchild; i++) {
6359 			struct usb_port *port_dev = hub->ports[i - 1];
6360 
6361 			connect_type = port_dev->connect_type;
6362 			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
6363 				u16 mask = 1 << i;
6364 
6365 				if (!(port_removable & mask)) {
6366 					dev_dbg(&port_dev->dev, "DeviceRemovable is changed to 1 according to platform information.\n");
6367 					port_removable |= mask;
6368 				}
6369 			}
6370 		}
6371 
6372 		desc->u.ss.DeviceRemovable = cpu_to_le16(port_removable);
6373 	}
6374 }
6375 
6376 #ifdef CONFIG_ACPI
6377 /**
6378  * usb_get_hub_port_acpi_handle - Get the usb port's acpi handle
6379  * @hdev: USB device belonging to the usb hub
6380  * @port1: port num of the port
6381  *
6382  * Return: Port's acpi handle if successful, %NULL if params are
6383  * invalid.
6384  */
usb_get_hub_port_acpi_handle(struct usb_device * hdev,int port1)6385 acpi_handle usb_get_hub_port_acpi_handle(struct usb_device *hdev,
6386 	int port1)
6387 {
6388 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
6389 
6390 	if (!hub)
6391 		return NULL;
6392 
6393 	return ACPI_HANDLE(&hub->ports[port1 - 1]->dev);
6394 }
6395 #endif
6396