33  * DOC: Hotplug
35  * Simply put, hotplug occurs when a display is connected to or disconnected
39  * Hotplug in i915 is handled in many different levels of abstraction.
43  * handlers gather the hotplug detect (HPD) information from relevant registers
44  * into a platform independent mask of hotplug pins that have fired.
47  * intel_hotplug.c does hotplug irq storm detection and mitigation, and passes
49  * regular hotplug).
53  * pulses, with failures and non-MST long pulses triggering regular hotplug
56  * The regular hotplug work function i915_hotplug_work_func() calls connector
57  * detect hooks, and, if connector status changes, triggers sending of hotplug
61  * the hotplug uevent, disabling or enabling the crtc as needed.
63  * The hotplug interrupt storm detection and mitigation code keeps track of the
64  * number of interrupts per hotplug pin per a period of time, and if the number
70  * Current implementation expects that hotplug interrupt storm will not be
134  * stored in @dev_priv->hotplug.hpd_storm_threshold which defaults to
140  * &dev_priv->hotplug.hpd_storm_threshold. However, some older systems also
148  * and should only be adjusted for automated hotplug testing.
155 	struct i915_hotplug *hpd = &dev_priv->hotplug;  in intel_hpd_irq_storm_detect()
163 	    (!long_hpd && !dev_priv->hotplug.hpd_short_storm_enabled))  in intel_hpd_irq_storm_detect()
209 		    dev_priv->hotplug.stats[pin].state != HPD_MARK_DISABLED)  in intel_hpd_irq_storm_switch_to_polling()
213 			 "switching from hotplug detection to polling\n",  in intel_hpd_irq_storm_switch_to_polling()
216 		dev_priv->hotplug.stats[pin].state = HPD_DISABLED;  in intel_hpd_irq_storm_switch_to_polling()
223 	/* Enable polling and queue hotplug re-enabling. */  in intel_hpd_irq_storm_switch_to_polling()
226 		mod_delayed_work(system_wq, &dev_priv->hotplug.reenable_work,  in intel_hpd_irq_storm_switch_to_polling()
235 			     hotplug.reenable_work.work);  in intel_hpd_irq_storm_reenable_work()
247 		if (dev_priv->hotplug.stats[pin].state != HPD_DISABLED)  in intel_hpd_irq_storm_reenable_work()
250 		dev_priv->hotplug.stats[pin].state = HPD_ENABLED;  in intel_hpd_irq_storm_reenable_work()
311 		container_of(work, struct drm_i915_private, hotplug.dig_port_work);  in i915_digport_work_func()
317 	long_port_mask = dev_priv->hotplug.long_port_mask;  in i915_digport_work_func()
318 	dev_priv->hotplug.long_port_mask = 0;  in i915_digport_work_func()
319 	short_port_mask = dev_priv->hotplug.short_port_mask;  in i915_digport_work_func()
320 	dev_priv->hotplug.short_port_mask = 0;  in i915_digport_work_func()
349 		dev_priv->hotplug.event_bits |= old_bits;  in i915_digport_work_func()
351 		queue_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work, 0);  in i915_digport_work_func()
356  * Handle hotplug events outside the interrupt handler proper.
362 			     hotplug.hotplug_work.work);  in i915_hotplug_work_func()
373 	DRM_DEBUG_KMS("running encoder hotplug functions\n");  in i915_hotplug_work_func()
377 	hpd_event_bits = dev_priv->hotplug.event_bits;  in i915_hotplug_work_func()
378 	dev_priv->hotplug.event_bits = 0;  in i915_hotplug_work_func()
379 	hpd_retry_bits = dev_priv->hotplug.retry_bits;  in i915_hotplug_work_func()
380 	dev_priv->hotplug.retry_bits = 0;  in i915_hotplug_work_func()
397 			DRM_DEBUG_KMS("Connector %s (pin %i) received hotplug event.\n",  in i915_hotplug_work_func()
400 			switch (intel_encoder->hotplug(intel_encoder,  in i915_hotplug_work_func()
424 		dev_priv->hotplug.retry_bits |= retry;  in i915_hotplug_work_func()
427 		mod_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work,  in i915_hotplug_work_func()
434  * intel_hpd_irq_handler - main hotplug irq handler
439  * This is the main hotplug irq handler for all platforms. The platform specific
440  * irq handlers call the platform specific hotplug irq handlers, which read and
446  * Here, we do hotplug irq storm detection and mitigation, and pass further
490 			dev_priv->hotplug.long_port_mask |= BIT(port);  in intel_hpd_irq_handler()
493 			dev_priv->hotplug.short_port_mask |= BIT(port);  in intel_hpd_irq_handler()
504 		if (dev_priv->hotplug.stats[pin].state == HPD_DISABLED) {  in intel_hpd_irq_handler()
508 			 * hotplug bits itself. So only WARN about unexpected  in intel_hpd_irq_handler()
516 		if (dev_priv->hotplug.stats[pin].state != HPD_ENABLED)  in intel_hpd_irq_handler()
527 			dev_priv->hotplug.event_bits |= BIT(pin);  in intel_hpd_irq_handler()
533 			dev_priv->hotplug.event_bits &= ~BIT(pin);  in intel_hpd_irq_handler()
541 	 * happens later in our hotplug work.  in intel_hpd_irq_handler()
548 	 * Our hotplug handler can grab modeset locks (by calling down into the  in intel_hpd_irq_handler()
554 		queue_work(dev_priv->hotplug.dp_wq, &dev_priv->hotplug.dig_port_work);  in intel_hpd_irq_handler()
556 		queue_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work, 0);  in intel_hpd_irq_handler()
563  * This function enables the hotplug support. It requires that interrupts have
564  * already been enabled with intel_irq_init_hw(). From this point on hotplug and
578 		dev_priv->hotplug.stats[i].count = 0;  in intel_hpd_init()
579 		dev_priv->hotplug.stats[i].state = HPD_ENABLED;  in intel_hpd_init()
582 	WRITE_ONCE(dev_priv->hotplug.poll_enabled, false);  in intel_hpd_init()
583 	schedule_work(&dev_priv->hotplug.poll_init_work);  in intel_hpd_init()
601 			     hotplug.poll_init_work);  in i915_hpd_poll_init_work()
609 	enabled = READ_ONCE(dev_priv->hotplug.poll_enabled);  in i915_hpd_poll_init_work()
650  * not they support hotplug detection. Under certain conditions HPD may not be
656  * dev->mode_config.mutex, we do the actual hotplug enabling in a seperate
663 	WRITE_ONCE(dev_priv->hotplug.poll_enabled, true);  in intel_hpd_poll_init()
671 	schedule_work(&dev_priv->hotplug.poll_init_work);  in intel_hpd_poll_init()
676 	INIT_DELAYED_WORK(&dev_priv->hotplug.hotplug_work,  in intel_hpd_init_work()
678 	INIT_WORK(&dev_priv->hotplug.dig_port_work, i915_digport_work_func);  in intel_hpd_init_work()
679 	INIT_WORK(&dev_priv->hotplug.poll_init_work, i915_hpd_poll_init_work);  in intel_hpd_init_work()
680 	INIT_DELAYED_WORK(&dev_priv->hotplug.reenable_work,  in intel_hpd_init_work()
688 	dev_priv->hotplug.long_port_mask = 0;  in intel_hpd_cancel_work()
689 	dev_priv->hotplug.short_port_mask = 0;  in intel_hpd_cancel_work()
690 	dev_priv->hotplug.event_bits = 0;  in intel_hpd_cancel_work()
691 	dev_priv->hotplug.retry_bits = 0;  in intel_hpd_cancel_work()
695 	cancel_work_sync(&dev_priv->hotplug.dig_port_work);  in intel_hpd_cancel_work()
696 	cancel_delayed_work_sync(&dev_priv->hotplug.hotplug_work);  in intel_hpd_cancel_work()
697 	cancel_work_sync(&dev_priv->hotplug.poll_init_work);  in intel_hpd_cancel_work()
698 	cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work);  in intel_hpd_cancel_work()
709 	if (dev_priv->hotplug.stats[pin].state == HPD_ENABLED) {  in intel_hpd_disable()
710 		dev_priv->hotplug.stats[pin].state = HPD_DISABLED;  in intel_hpd_disable()
724 	dev_priv->hotplug.stats[pin].state = HPD_ENABLED;  in intel_hpd_enable()