31  * DOC: Hotplug
33  * Simply put, hotplug occurs when a display is connected to or disconnected
37  * Hotplug in i915 is handled in many different levels of abstraction.
41  * handlers gather the hotplug detect (HPD) information from relevant registers
42  * into a platform independent mask of hotplug pins that have fired.
45  * intel_hotplug.c does hotplug irq storm detection and mitigation, and passes
47  * regular hotplug).
51  * pulses, with failures and non-MST long pulses triggering regular hotplug
54  * The regular hotplug work function i915_hotplug_work_func() calls connector
55  * detect hooks, and, if connector status changes, triggers sending of hotplug
59  * the hotplug uevent, disabling or enabling the crtc as needed.
61  * The hotplug interrupt storm detection and mitigation code keeps track of the
62  * number of interrupts per hotplug pin per a period of time, and if the number
68  * Current implementation expects that hotplug interrupt storm will not be
121  * stored in @dev_priv->hotplug.hpd_storm_threshold which defaults to
127  * &dev_priv->hotplug.hpd_storm_threshold. However, some older systems also
135  * and should only be adjusted for automated hotplug testing.
142 	struct i915_hotplug *hpd = &dev_priv->hotplug;  in intel_hpd_irq_storm_detect()
150 	    (!long_hpd && !dev_priv->hotplug.hpd_short_storm_enabled))  in intel_hpd_irq_storm_detect()
193 		    dev_priv->hotplug.stats[pin].state != HPD_MARK_DISABLED)  in intel_hpd_irq_storm_switch_to_polling()
198 			 "switching from hotplug detection to polling\n",  in intel_hpd_irq_storm_switch_to_polling()
201 		dev_priv->hotplug.stats[pin].state = HPD_DISABLED;  in intel_hpd_irq_storm_switch_to_polling()
208 	/* Enable polling and queue hotplug re-enabling. */  in intel_hpd_irq_storm_switch_to_polling()
211 		mod_delayed_work(system_wq, &dev_priv->hotplug.reenable_work,  in intel_hpd_irq_storm_switch_to_polling()
226 			     hotplug.reenable_work.work);  in intel_hpd_irq_storm_reenable_work()
241 		    dev_priv->hotplug.stats[pin].state != HPD_DISABLED)  in intel_hpd_irq_storm_reenable_work()
253 		if (dev_priv->hotplug.stats[pin].state == HPD_DISABLED)  in intel_hpd_irq_storm_reenable_work()
254 			dev_priv->hotplug.stats[pin].state = HPD_ENABLED;  in intel_hpd_irq_storm_reenable_work()
305 		container_of(work, struct drm_i915_private, hotplug.dig_port_work);  in i915_digport_work_func()
311 	long_port_mask = dev_priv->hotplug.long_port_mask;  in i915_digport_work_func()
312 	dev_priv->hotplug.long_port_mask = 0;  in i915_digport_work_func()
313 	short_port_mask = dev_priv->hotplug.short_port_mask;  in i915_digport_work_func()
314 	dev_priv->hotplug.short_port_mask = 0;  in i915_digport_work_func()
343 		dev_priv->hotplug.event_bits |= old_bits;  in i915_digport_work_func()
345 		queue_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work, 0);  in i915_digport_work_func()
361 	i915->hotplug.short_port_mask |= BIT(dig_port->base.port);  in intel_hpd_trigger_irq()
364 	queue_work(i915->hotplug.dp_wq, &i915->hotplug.dig_port_work);  in intel_hpd_trigger_irq()
368  * Handle hotplug events outside the interrupt handler proper.
374 			     hotplug.hotplug_work.work);  in i915_hotplug_work_func()
383 	drm_dbg_kms(&dev_priv->drm, "running encoder hotplug functions\n");  in i915_hotplug_work_func()
387 	hpd_event_bits = dev_priv->hotplug.event_bits;  in i915_hotplug_work_func()
388 	dev_priv->hotplug.event_bits = 0;  in i915_hotplug_work_func()
389 	hpd_retry_bits = dev_priv->hotplug.retry_bits;  in i915_hotplug_work_func()
390 	dev_priv->hotplug.retry_bits = 0;  in i915_hotplug_work_func()
417 				    "Connector %s (pin %i) received hotplug event. (retry %d)\n",  in i915_hotplug_work_func()
421 			switch (encoder->hotplug(encoder, connector)) {  in i915_hotplug_work_func()
443 		dev_priv->hotplug.retry_bits |= retry;  in i915_hotplug_work_func()
446 		mod_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work,  in i915_hotplug_work_func()
453  * intel_hpd_irq_handler - main hotplug irq handler
458  * This is the main hotplug irq handler for all platforms. The platform specific
459  * irq handlers call the platform specific hotplug irq handlers, which read and
465  * Here, we do hotplug irq storm detection and mitigation, and pass further
510 			dev_priv->hotplug.long_port_mask |= BIT(port);  in intel_hpd_irq_handler()
513 			dev_priv->hotplug.short_port_mask |= BIT(port);  in intel_hpd_irq_handler()
524 		if (dev_priv->hotplug.stats[pin].state == HPD_DISABLED) {  in intel_hpd_irq_handler()
528 			 * hotplug bits itself. So only WARN about unexpected  in intel_hpd_irq_handler()
537 		if (dev_priv->hotplug.stats[pin].state != HPD_ENABLED)  in intel_hpd_irq_handler()
548 			dev_priv->hotplug.event_bits |= BIT(pin);  in intel_hpd_irq_handler()
554 			dev_priv->hotplug.event_bits &= ~BIT(pin);  in intel_hpd_irq_handler()
562 	 * happens later in our hotplug work.  in intel_hpd_irq_handler()
569 	 * Our hotplug handler can grab modeset locks (by calling down into the  in intel_hpd_irq_handler()
575 		queue_work(dev_priv->hotplug.dp_wq, &dev_priv->hotplug.dig_port_work);  in intel_hpd_irq_handler()
577 		queue_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work, 0);  in intel_hpd_irq_handler()
584  * This function enables the hotplug support. It requires that interrupts have
585  * already been enabled with intel_irq_init_hw(). From this point on hotplug and
602 		dev_priv->hotplug.stats[i].count = 0;  in intel_hpd_init()
603 		dev_priv->hotplug.stats[i].state = HPD_ENABLED;  in intel_hpd_init()
619 			     hotplug.poll_init_work);  in i915_hpd_poll_init_work()
627 	enabled = READ_ONCE(dev_priv->hotplug.poll_enabled);  in i915_hpd_poll_init_work()
669  * dev->mode_config.mutex, we do the actual hotplug enabling in a seperate
679 	WRITE_ONCE(dev_priv->hotplug.poll_enabled, true);  in intel_hpd_poll_enable()
687 	schedule_work(&dev_priv->hotplug.poll_init_work);  in intel_hpd_poll_enable()
701  * dev->mode_config.mutex, we do the actual hotplug enabling in a seperate
714 	WRITE_ONCE(dev_priv->hotplug.poll_enabled, false);  in intel_hpd_poll_disable()
715 	schedule_work(&dev_priv->hotplug.poll_init_work);  in intel_hpd_poll_disable()
720 	INIT_DELAYED_WORK(&dev_priv->hotplug.hotplug_work,  in intel_hpd_init_work()
722 	INIT_WORK(&dev_priv->hotplug.dig_port_work, i915_digport_work_func);  in intel_hpd_init_work()
723 	INIT_WORK(&dev_priv->hotplug.poll_init_work, i915_hpd_poll_init_work);  in intel_hpd_init_work()
724 	INIT_DELAYED_WORK(&dev_priv->hotplug.reenable_work,  in intel_hpd_init_work()
735 	dev_priv->hotplug.long_port_mask = 0;  in intel_hpd_cancel_work()
736 	dev_priv->hotplug.short_port_mask = 0;  in intel_hpd_cancel_work()
737 	dev_priv->hotplug.event_bits = 0;  in intel_hpd_cancel_work()
738 	dev_priv->hotplug.retry_bits = 0;  in intel_hpd_cancel_work()
742 	cancel_work_sync(&dev_priv->hotplug.dig_port_work);  in intel_hpd_cancel_work()
743 	cancel_delayed_work_sync(&dev_priv->hotplug.hotplug_work);  in intel_hpd_cancel_work()
744 	cancel_work_sync(&dev_priv->hotplug.poll_init_work);  in intel_hpd_cancel_work()
745 	cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work);  in intel_hpd_cancel_work()
756 	if (dev_priv->hotplug.stats[pin].state == HPD_ENABLED) {  in intel_hpd_disable()
757 		dev_priv->hotplug.stats[pin].state = HPD_DISABLED;  in intel_hpd_disable()
771 	dev_priv->hotplug.stats[pin].state = HPD_ENABLED;  in intel_hpd_enable()