From f7d16a538ad226d8b60990f8628e1c81787ee62c Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Thu, 4 Jan 2024 10:29:58 +0200 Subject: [PATCH] drm/i915: Keep the connector polled state disabled after storm MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit If an HPD IRQ storm is detected on a connector during driver loading or system suspend/resume - disabling the IRQ and switching to polling - the polling may get disabled too early - before the intended 2 minute HPD_STORM_REENABLE_DELAY - with the HPD IRQ staying disabled for this duration. One such sequence is: Thread#1 Thread#2 intel_display_driver_probe()-> intel_hpd_init()-> (HPD IRQ gets enabled) . intel_hpd_irq_handler()-> . intel_hpd_irq_storm_detect() . intel_hpd_irq_setup()-> . (HPD IRQ gets disabled) . queue_delayed_work(hotplug.hotplug_work) . ... . i915_hotplug_work_func()-> . intel_hpd_irq_storm_switch_to_polling()-> . (polling enabled) . intel_hpd_poll_disable()-> queue_work(hotplug.poll_init_work) ... i915_hpd_poll_init_work()-> (polling gets disabled, HPD IRQ is still disabled) ... (Connector is neither polled or detected via HPD IRQs for 2 minutes) intel_hpd_irq_storm_reenable_work()-> (HPD IRQ gets enabled) To avoid the above 2 minute state without either polling or enabled HPD IRQ, leave the connector's polling mode unchanged in i915_hpd_poll_init_work() if its HPD IRQ got disabled after an IRQ storm indicated by the connector's HPD_DISABLED pin state. Link: https://patchwork.freedesktop.org/patch/msgid/20240104083008.2715733-3-imre.deak@intel.com Reviewed-by: Jouni Högander Signed-off-by: Imre Deak --- drivers/gpu/drm/i915/display/intel_hotplug.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c b/drivers/gpu/drm/i915/display/intel_hotplug.c index 0c0700c6ec66..74513c3d3690 100644 --- a/drivers/gpu/drm/i915/display/intel_hotplug.c +++ b/drivers/gpu/drm/i915/display/intel_hotplug.c @@ -710,6 +710,8 @@ static void i915_hpd_poll_init_work(struct work_struct *work) cancel_work(&dev_priv->display.hotplug.poll_init_work); } + spin_lock_irq(&dev_priv->irq_lock); + drm_connector_list_iter_begin(&dev_priv->drm, &conn_iter); for_each_intel_connector_iter(connector, &conn_iter) { enum hpd_pin pin; @@ -718,6 +720,9 @@ static void i915_hpd_poll_init_work(struct work_struct *work) if (pin == HPD_NONE) continue; + if (dev_priv->display.hotplug.stats[pin].state == HPD_DISABLED) + continue; + connector->base.polled = connector->polled; if (enabled && connector->base.polled == DRM_CONNECTOR_POLL_HPD) @@ -726,6 +731,8 @@ static void i915_hpd_poll_init_work(struct work_struct *work) } drm_connector_list_iter_end(&conn_iter); + spin_unlock_irq(&dev_priv->irq_lock); + if (enabled) drm_kms_helper_poll_reschedule(&dev_priv->drm); -- 2.39.5