37  * DOC: Hotplug
39  * Simply put, hotplug occurs when a display is connected to or disconnected
43  * Hotplug in i915 is handled in many different levels of abstraction.
47  * handlers gather the hotplug detect (HPD) information from relevant registers
48  * into a platform independent mask of hotplug pins that have fired.
51  * intel_hotplug.c does hotplug irq storm detection and mitigation, and passes
53  * regular hotplug).
57  * pulses, with failures and non-MST long pulses triggering regular hotplug
60  * The regular hotplug work function i915_hotplug_work_func() calls connector
61  * detect hooks, and, if connector status changes, triggers sending of hotplug
65  * the hotplug uevent, disabling or enabling the crtc as needed.
67  * The hotplug interrupt storm detection and mitigation code keeps track of the
68  * number of interrupts per hotplug pin per a period of time, and if the number
74  * Current implementation expects that hotplug interrupt storm will not be
130  * stored in @dev_priv->display.hotplug.hpd_storm_threshold which defaults to
136  * &dev_priv->display.hotplug.hpd_storm_threshold. However, some older systems also
144  * and should only be adjusted for automated hotplug testing.
151 	struct intel_hotplug *hpd = &dev_priv->display.hotplug;  in intel_hpd_irq_storm_detect()
159 	    (!long_hpd && !dev_priv->display.hotplug.hpd_short_storm_enabled))  in intel_hpd_irq_storm_detect()
187 	return i915->display.hotplug.detection_work_enabled;  in detection_work_enabled()
241 		    dev_priv->display.hotplug.stats[pin].state != HPD_MARK_DISABLED)  in intel_hpd_irq_storm_switch_to_polling()
246 			 "switching from hotplug detection to polling\n",  in intel_hpd_irq_storm_switch_to_polling()
249 		dev_priv->display.hotplug.stats[pin].state = HPD_DISABLED;  in intel_hpd_irq_storm_switch_to_polling()
256 	/* Enable polling and queue hotplug re-enabling. */  in intel_hpd_irq_storm_switch_to_polling()
260 					   &dev_priv->display.hotplug.reenable_work,  in intel_hpd_irq_storm_switch_to_polling()
269 			     display.hotplug.reenable_work.work);  in intel_hpd_irq_storm_reenable_work()
283 		    dev_priv->display.hotplug.stats[pin].state != HPD_DISABLED)  in intel_hpd_irq_storm_reenable_work()
295 		if (dev_priv->display.hotplug.stats[pin].state == HPD_DISABLED)  in intel_hpd_irq_storm_reenable_work()
296 			dev_priv->display.hotplug.stats[pin].state = HPD_ENABLED;  in intel_hpd_irq_storm_reenable_work()
355 		container_of(work, struct drm_i915_private, display.hotplug.dig_port_work);  in i915_digport_work_func()
361 	long_port_mask = dev_priv->display.hotplug.long_port_mask;  in i915_digport_work_func()
362 	dev_priv->display.hotplug.long_port_mask = 0;  in i915_digport_work_func()
363 	short_port_mask = dev_priv->display.hotplug.short_port_mask;  in i915_digport_work_func()
364 	dev_priv->display.hotplug.short_port_mask = 0;  in i915_digport_work_func()
393 		dev_priv->display.hotplug.event_bits |= old_bits;  in i915_digport_work_func()
395 					     &dev_priv->display.hotplug.hotplug_work, 0);  in i915_digport_work_func()
412 	i915->display.hotplug.short_port_mask |= BIT(dig_port->base.port);  in intel_hpd_trigger_irq()
415 	queue_work(i915->display.hotplug.dp_wq, &i915->display.hotplug.dig_port_work);  in intel_hpd_trigger_irq()
419  * Handle hotplug events outside the interrupt handler proper.
425 			     display.hotplug.hotplug_work.work);  in i915_hotplug_work_func()
435 	drm_dbg_kms(&dev_priv->drm, "running encoder hotplug functions\n");  in i915_hotplug_work_func()
439 	hpd_event_bits = dev_priv->display.hotplug.event_bits;  in i915_hotplug_work_func()
440 	dev_priv->display.hotplug.event_bits = 0;  in i915_hotplug_work_func()
441 	hpd_retry_bits = dev_priv->display.hotplug.retry_bits;  in i915_hotplug_work_func()
442 	dev_priv->display.hotplug.retry_bits = 0;  in i915_hotplug_work_func()
449 	/* Skip calling encode hotplug handlers if ignore long HPD set*/  in i915_hotplug_work_func()
450 	if (dev_priv->display.hotplug.ignore_long_hpd) {  in i915_hotplug_work_func()
451 		drm_dbg_kms(&dev_priv->drm, "Ignore HPD flag on - skip encoder hotplug handlers\n");  in i915_hotplug_work_func()
476 				    "Connector %s (pin %i) received hotplug event. (retry %d)\n",  in i915_hotplug_work_func()
480 			switch (encoder->hotplug(encoder, connector)) {  in i915_hotplug_work_func()
512 		dev_priv->display.hotplug.retry_bits |= retry;  in i915_hotplug_work_func()
515 					   &dev_priv->display.hotplug.hotplug_work,  in i915_hotplug_work_func()
523  * intel_hpd_irq_handler - main hotplug irq handler
528  * This is the main hotplug irq handler for all platforms. The platform specific
529  * irq handlers call the platform specific hotplug irq handlers, which read and
535  * Here, we do hotplug irq storm detection and mitigation, and pass further
580 			dev_priv->display.hotplug.long_port_mask |= BIT(port);  in intel_hpd_irq_handler()
583 			dev_priv->display.hotplug.short_port_mask |= BIT(port);  in intel_hpd_irq_handler()
594 		if (dev_priv->display.hotplug.stats[pin].state == HPD_DISABLED) {  in intel_hpd_irq_handler()
598 			 * hotplug bits itself. So only WARN about unexpected  in intel_hpd_irq_handler()
607 		if (dev_priv->display.hotplug.stats[pin].state != HPD_ENABLED)  in intel_hpd_irq_handler()
618 			dev_priv->display.hotplug.event_bits |= BIT(pin);  in intel_hpd_irq_handler()
624 			dev_priv->display.hotplug.event_bits &= ~BIT(pin);  in intel_hpd_irq_handler()
632 	 * happens later in our hotplug work.  in intel_hpd_irq_handler()
638 	 * Our hotplug handler can grab modeset locks (by calling down into the  in intel_hpd_irq_handler()
644 		queue_work(dev_priv->display.hotplug.dp_wq, &dev_priv->display.hotplug.dig_port_work);  in intel_hpd_irq_handler()
647 					     &dev_priv->display.hotplug.hotplug_work, 0);  in intel_hpd_irq_handler()
656  * This function enables the hotplug support. It requires that interrupts have
657  * already been enabled with intel_irq_init_hw(). From this point on hotplug and
674 		dev_priv->display.hotplug.stats[i].count = 0;  in intel_hpd_init()
675 		dev_priv->display.hotplug.stats[i].state = HPD_ENABLED;  in intel_hpd_init()
734 			     display.hotplug.poll_init_work);  in i915_hpd_poll_init_work()
742 	enabled = READ_ONCE(dev_priv->display.hotplug.poll_enabled);  in i915_hpd_poll_init_work()
753 			    READ_ONCE(dev_priv->display.hotplug.poll_enabled));  in i915_hpd_poll_init_work()
754 		cancel_work(&dev_priv->display.hotplug.poll_init_work);  in i915_hpd_poll_init_work()
767 		if (dev_priv->display.hotplug.stats[pin].state == HPD_DISABLED)  in i915_hpd_poll_init_work()
809  * dev->mode_config.mutex, we do the actual hotplug enabling in a seperate
822 	WRITE_ONCE(dev_priv->display.hotplug.poll_enabled, true);  in intel_hpd_poll_enable()
832 			     &dev_priv->display.hotplug.poll_init_work);  in intel_hpd_poll_enable()
847  * dev->mode_config.mutex, we do the actual hotplug enabling in a seperate
860 	WRITE_ONCE(dev_priv->display.hotplug.poll_enabled, false);  in intel_hpd_poll_disable()
864 			     &dev_priv->display.hotplug.poll_init_work);  in intel_hpd_poll_disable()
870 	INIT_DELAYED_WORK(&i915->display.hotplug.hotplug_work,  in intel_hpd_init_early()
872 	INIT_WORK(&i915->display.hotplug.dig_port_work, i915_digport_work_func);  in intel_hpd_init_early()
873 	INIT_WORK(&i915->display.hotplug.poll_init_work, i915_hpd_poll_init_work);  in intel_hpd_init_early()
874 	INIT_DELAYED_WORK(&i915->display.hotplug.reenable_work,  in intel_hpd_init_early()
877 	i915->display.hotplug.hpd_storm_threshold = HPD_STORM_DEFAULT_THRESHOLD;  in intel_hpd_init_early()
884 	i915->display.hotplug.hpd_short_storm_enabled = !HAS_DP_MST(i915);  in intel_hpd_init_early()
891 	if (cancel_delayed_work_sync(&i915->display.hotplug.hotplug_work))  in cancel_all_detection_work()
893 	if (cancel_work_sync(&i915->display.hotplug.poll_init_work))  in cancel_all_detection_work()
895 	if (cancel_delayed_work_sync(&i915->display.hotplug.reenable_work))  in cancel_all_detection_work()
908 	dev_priv->display.hotplug.long_port_mask = 0;  in intel_hpd_cancel_work()
909 	dev_priv->display.hotplug.short_port_mask = 0;  in intel_hpd_cancel_work()
910 	dev_priv->display.hotplug.event_bits = 0;  in intel_hpd_cancel_work()
911 	dev_priv->display.hotplug.retry_bits = 0;  in intel_hpd_cancel_work()
915 	cancel_work_sync(&dev_priv->display.hotplug.dig_port_work);  in intel_hpd_cancel_work()
918 	 * All other work triggered by hotplug events should be canceled by  in intel_hpd_cancel_work()
922 		drm_dbg_kms(&dev_priv->drm, "Hotplug detection work still active\n");  in intel_hpd_cancel_work()
933 	if (dev_priv->display.hotplug.stats[pin].state == HPD_ENABLED) {  in intel_hpd_disable()
934 		dev_priv->display.hotplug.stats[pin].state = HPD_DISABLED;  in intel_hpd_disable()
948 	dev_priv->display.hotplug.stats[pin].state = HPD_ENABLED;  in intel_hpd_enable()
959 	if (i915->display.hotplug.event_bits ||  in queue_work_for_missed_irqs()
960 	    i915->display.hotplug.retry_bits)  in queue_work_for_missed_irqs()
964 		switch (i915->display.hotplug.stats[pin].state) {  in queue_work_for_missed_irqs()
971 			MISSING_CASE(i915->display.hotplug.stats[pin].state);  in queue_work_for_missed_irqs()
976 		queue_delayed_detection_work(i915, &i915->display.hotplug.hotplug_work, 0);  in queue_work_for_missed_irqs()
982 	i915->display.hotplug.detection_work_enabled = true;  in intel_hpd_enable_detection_work()
990 	i915->display.hotplug.detection_work_enabled = false;  in intel_hpd_disable_detection_work()
1002 	ret = queue_delayed_detection_work(i915, &i915->display.hotplug.hotplug_work, 0);  in intel_hpd_schedule_detection()
1011 	struct intel_hotplug *hotplug = &dev_priv->display.hotplug;  in i915_hpd_storm_ctl_show()  local
1017 	flush_work(&dev_priv->display.hotplug.dig_port_work);  in i915_hpd_storm_ctl_show()
1018 	flush_delayed_work(&dev_priv->display.hotplug.hotplug_work);  in i915_hpd_storm_ctl_show()
1020 	seq_printf(m, "Threshold: %d\n", hotplug->hpd_storm_threshold);  in i915_hpd_storm_ctl_show()
1022 		   str_yes_no(delayed_work_pending(&hotplug->reenable_work)));  in i915_hpd_storm_ctl_show()
1033 	struct intel_hotplug *hotplug = &dev_priv->display.hotplug;  in i915_hpd_storm_ctl_write()  local
1065 	hotplug->hpd_storm_threshold = new_threshold;  in i915_hpd_storm_ctl_write()
1068 		hotplug->stats[i].count = 0;  in i915_hpd_storm_ctl_write()
1072 	flush_delayed_work(&dev_priv->display.hotplug.reenable_work);  in i915_hpd_storm_ctl_write()
1096 		   str_yes_no(dev_priv->display.hotplug.hpd_short_storm_enabled));  in i915_hpd_short_storm_ctl_show()
1114 	struct intel_hotplug *hotplug = &dev_priv->display.hotplug;  in i915_hpd_short_storm_ctl_write()  local
1143 	hotplug->hpd_short_storm_enabled = new_state;  in i915_hpd_short_storm_ctl_write()
1146 		hotplug->stats[i].count = 0;  in i915_hpd_short_storm_ctl_write()
1150 	flush_delayed_work(&dev_priv->display.hotplug.reenable_work);  in i915_hpd_short_storm_ctl_write()
1173 			    &i915->display.hotplug.ignore_long_hpd);  in intel_hpd_debugfs_register()