From cd572b3bb27e86f4a4c814acabbf1f197259c011 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Thu, 4 Jan 2024 10:30:04 +0200 Subject: [PATCH] drm/i915: Disable hotplug detection works during driver init/shutdown MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As described in the previous patch, an unexpected connector detection/modeset started from the intel_hotplug::hotplug_work can happen during the driver init/shutdown sequence. Prevent these by disabling the queuing of and flushing all the intel_hotplug work that can start them at the beginning of the init/shutdown sequence and allow the queuing only while the display is in the initialized state. Other work items - like the intel_connector::modeset_retry_work or the MST probe works - are still enabled and can start a detection/modeset, but after the previous patch these will be rejected. Disabling these works as well is for a follow-up patchset. Link: https://patchwork.freedesktop.org/patch/msgid/20240104083008.2715733-9-imre.deak@intel.com Reviewed-by: Jouni Högander Signed-off-by: Imre Deak --- .../gpu/drm/i915/display/intel_display_core.h | 6 + .../drm/i915/display/intel_display_driver.c | 4 + drivers/gpu/drm/i915/display/intel_dp.c | 2 +- drivers/gpu/drm/i915/display/intel_hotplug.c | 158 +++++++++++++++--- drivers/gpu/drm/i915/display/intel_hotplug.h | 4 + 5 files changed, 154 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_display_core.h b/drivers/gpu/drm/i915/display/intel_display_core.h index cd3b34459b87..54278db823df 100644 --- a/drivers/gpu/drm/i915/display/intel_display_core.h +++ b/drivers/gpu/drm/i915/display/intel_display_core.h @@ -174,6 +174,12 @@ struct intel_hotplug { struct work_struct poll_init_work; bool poll_enabled; + /* + * Queuing of hotplug_work, reenable_work and poll_init_work is + * enabled. Protected by drm_i915_private::irq_lock. + */ + bool detection_work_enabled; + unsigned int hpd_storm_threshold; /* Whether or not to count short HPD IRQs in HPD storms */ u8 hpd_short_storm_enabled; diff --git a/drivers/gpu/drm/i915/display/intel_display_driver.c b/drivers/gpu/drm/i915/display/intel_display_driver.c index dcdd26eefaaf..ecf9cb74734b 100644 --- a/drivers/gpu/drm/i915/display/intel_display_driver.c +++ b/drivers/gpu/drm/i915/display/intel_display_driver.c @@ -309,6 +309,8 @@ static void set_display_access(struct drm_i915_private *i915, void intel_display_driver_enable_user_access(struct drm_i915_private *i915) { set_display_access(i915, true, NULL); + + intel_hpd_enable_detection_work(i915); } /** @@ -330,6 +332,8 @@ void intel_display_driver_enable_user_access(struct drm_i915_private *i915) */ void intel_display_driver_disable_user_access(struct drm_i915_private *i915) { + intel_hpd_disable_detection_work(i915); + set_display_access(i915, false, current); } diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 8803a9323353..6ce003b97dcc 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -6019,7 +6019,7 @@ static void intel_dp_oob_hotplug_event(struct drm_connector *connector) spin_lock_irq(&i915->irq_lock); i915->display.hotplug.event_bits |= BIT(encoder->hpd_pin); spin_unlock_irq(&i915->irq_lock); - queue_delayed_work(i915->unordered_wq, &i915->display.hotplug.hotplug_work, 0); + intel_hpd_schedule_detection(i915); } static const struct drm_connector_funcs intel_dp_connector_funcs = { diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c b/drivers/gpu/drm/i915/display/intel_hotplug.c index 74513c3d3690..d9ec349f3c8c 100644 --- a/drivers/gpu/drm/i915/display/intel_hotplug.c +++ b/drivers/gpu/drm/i915/display/intel_hotplug.c @@ -177,6 +177,46 @@ static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv, return storm; } +static bool detection_work_enabled(struct drm_i915_private *i915) +{ + lockdep_assert_held(&i915->irq_lock); + + return i915->display.hotplug.detection_work_enabled; +} + +static bool +mod_delayed_detection_work(struct drm_i915_private *i915, struct delayed_work *work, int delay) +{ + lockdep_assert_held(&i915->irq_lock); + + if (!detection_work_enabled(i915)) + return false; + + return mod_delayed_work(i915->unordered_wq, work, delay); +} + +static bool +queue_delayed_detection_work(struct drm_i915_private *i915, struct delayed_work *work, int delay) +{ + lockdep_assert_held(&i915->irq_lock); + + if (!detection_work_enabled(i915)) + return false; + + return queue_delayed_work(i915->unordered_wq, work, delay); +} + +static bool +queue_detection_work(struct drm_i915_private *i915, struct work_struct *work) +{ + lockdep_assert_held(&i915->irq_lock); + + if (!detection_work_enabled(i915)) + return false; + + return queue_work(i915->unordered_wq, work); +} + static void intel_hpd_irq_storm_switch_to_polling(struct drm_i915_private *dev_priv) { @@ -213,9 +253,9 @@ intel_hpd_irq_storm_switch_to_polling(struct drm_i915_private *dev_priv) /* Enable polling and queue hotplug re-enabling. */ if (hpd_disabled) { drm_kms_helper_poll_reschedule(&dev_priv->drm); - mod_delayed_work(dev_priv->unordered_wq, - &dev_priv->display.hotplug.reenable_work, - msecs_to_jiffies(HPD_STORM_REENABLE_DELAY)); + mod_delayed_detection_work(dev_priv, + &dev_priv->display.hotplug.reenable_work, + msecs_to_jiffies(HPD_STORM_REENABLE_DELAY)); } } @@ -348,9 +388,9 @@ static void i915_digport_work_func(struct work_struct *work) if (old_bits) { spin_lock_irq(&dev_priv->irq_lock); dev_priv->display.hotplug.event_bits |= old_bits; + queue_delayed_detection_work(dev_priv, + &dev_priv->display.hotplug.hotplug_work, 0); spin_unlock_irq(&dev_priv->irq_lock); - queue_delayed_work(dev_priv->unordered_wq, - &dev_priv->display.hotplug.hotplug_work, 0); } } @@ -467,11 +507,11 @@ static void i915_hotplug_work_func(struct work_struct *work) if (retry) { spin_lock_irq(&dev_priv->irq_lock); dev_priv->display.hotplug.retry_bits |= retry; - spin_unlock_irq(&dev_priv->irq_lock); - mod_delayed_work(dev_priv->unordered_wq, - &dev_priv->display.hotplug.hotplug_work, - msecs_to_jiffies(HPD_RETRY_DELAY)); + mod_delayed_detection_work(dev_priv, + &dev_priv->display.hotplug.hotplug_work, + msecs_to_jiffies(HPD_RETRY_DELAY)); + spin_unlock_irq(&dev_priv->irq_lock); } } @@ -590,7 +630,6 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv, */ if (storm_detected) intel_hpd_irq_setup(dev_priv); - spin_unlock(&dev_priv->irq_lock); /* * Our hotplug handler can grab modeset locks (by calling down into the @@ -601,8 +640,10 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv, if (queue_dig) queue_work(dev_priv->display.hotplug.dp_wq, &dev_priv->display.hotplug.dig_port_work); if (queue_hp) - queue_delayed_work(dev_priv->unordered_wq, - &dev_priv->display.hotplug.hotplug_work, 0); + queue_delayed_detection_work(dev_priv, + &dev_priv->display.hotplug.hotplug_work, 0); + + spin_unlock(&dev_priv->irq_lock); } /** @@ -781,8 +822,10 @@ void intel_hpd_poll_enable(struct drm_i915_private *dev_priv) * As well, there's no issue if we race here since we always reschedule * this worker anyway */ - queue_work(dev_priv->unordered_wq, - &dev_priv->display.hotplug.poll_init_work); + spin_lock_irq(&dev_priv->irq_lock); + queue_detection_work(dev_priv, + &dev_priv->display.hotplug.poll_init_work); + spin_unlock_irq(&dev_priv->irq_lock); } /** @@ -810,8 +853,11 @@ void intel_hpd_poll_disable(struct drm_i915_private *dev_priv) return; WRITE_ONCE(dev_priv->display.hotplug.poll_enabled, false); - queue_work(dev_priv->unordered_wq, - &dev_priv->display.hotplug.poll_init_work); + + spin_lock_irq(&dev_priv->irq_lock); + queue_detection_work(dev_priv, + &dev_priv->display.hotplug.poll_init_work); + spin_unlock_irq(&dev_priv->irq_lock); } void intel_hpd_init_early(struct drm_i915_private *i915) @@ -833,6 +879,20 @@ void intel_hpd_init_early(struct drm_i915_private *i915) i915->display.hotplug.hpd_short_storm_enabled = !HAS_DP_MST(i915); } +static bool cancel_all_detection_work(struct drm_i915_private *i915) +{ + bool was_pending = false; + + if (cancel_delayed_work_sync(&i915->display.hotplug.hotplug_work)) + was_pending = true; + if (cancel_work_sync(&i915->display.hotplug.poll_init_work)) + was_pending = true; + if (cancel_delayed_work_sync(&i915->display.hotplug.reenable_work)) + was_pending = true; + + return was_pending; +} + void intel_hpd_cancel_work(struct drm_i915_private *dev_priv) { if (!HAS_DISPLAY(dev_priv)) @@ -848,9 +908,13 @@ void intel_hpd_cancel_work(struct drm_i915_private *dev_priv) spin_unlock_irq(&dev_priv->irq_lock); cancel_work_sync(&dev_priv->display.hotplug.dig_port_work); - cancel_delayed_work_sync(&dev_priv->display.hotplug.hotplug_work); - cancel_work_sync(&dev_priv->display.hotplug.poll_init_work); - cancel_delayed_work_sync(&dev_priv->display.hotplug.reenable_work); + + /* + * All other work triggered by hotplug events should be canceled by + * now. + */ + if (cancel_all_detection_work(dev_priv)) + drm_dbg_kms(&dev_priv->drm, "Hotplug detection work still active\n"); } bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin) @@ -880,6 +944,62 @@ void intel_hpd_enable(struct drm_i915_private *dev_priv, enum hpd_pin pin) spin_unlock_irq(&dev_priv->irq_lock); } +static void queue_work_for_missed_irqs(struct drm_i915_private *i915) +{ + bool queue_work = false; + enum hpd_pin pin; + + lockdep_assert_held(&i915->irq_lock); + + if (i915->display.hotplug.event_bits || + i915->display.hotplug.retry_bits) + queue_work = true; + + for_each_hpd_pin(pin) { + switch (i915->display.hotplug.stats[pin].state) { + case HPD_MARK_DISABLED: + queue_work = true; + break; + case HPD_ENABLED: + break; + default: + MISSING_CASE(i915->display.hotplug.stats[pin].state); + } + } + + if (queue_work) + queue_delayed_detection_work(i915, &i915->display.hotplug.hotplug_work, 0); +} + +void intel_hpd_enable_detection_work(struct drm_i915_private *i915) +{ + spin_lock_irq(&i915->irq_lock); + i915->display.hotplug.detection_work_enabled = true; + queue_work_for_missed_irqs(i915); + spin_unlock_irq(&i915->irq_lock); +} + +void intel_hpd_disable_detection_work(struct drm_i915_private *i915) +{ + spin_lock_irq(&i915->irq_lock); + i915->display.hotplug.detection_work_enabled = false; + spin_unlock_irq(&i915->irq_lock); + + cancel_all_detection_work(i915); +} + +bool intel_hpd_schedule_detection(struct drm_i915_private *i915) +{ + unsigned long flags; + bool ret; + + spin_lock_irqsave(&i915->irq_lock, flags); + ret = queue_delayed_detection_work(i915, &i915->display.hotplug.hotplug_work, 0); + spin_unlock_irqrestore(&i915->irq_lock, flags); + + return ret; +} + static int i915_hpd_storm_ctl_show(struct seq_file *m, void *data) { struct drm_i915_private *dev_priv = m->private; diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.h b/drivers/gpu/drm/i915/display/intel_hotplug.h index 424ae5dbf5a0..a17253ddec83 100644 --- a/drivers/gpu/drm/i915/display/intel_hotplug.h +++ b/drivers/gpu/drm/i915/display/intel_hotplug.h @@ -30,4 +30,8 @@ bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin); void intel_hpd_enable(struct drm_i915_private *dev_priv, enum hpd_pin pin); void intel_hpd_debugfs_register(struct drm_i915_private *i915); +void intel_hpd_enable_detection_work(struct drm_i915_private *i915); +void intel_hpd_disable_detection_work(struct drm_i915_private *i915); +bool intel_hpd_schedule_detection(struct drm_i915_private *i915); + #endif /* __INTEL_HOTPLUG_H__ */