So far we had a race during error capturing where a power domain could get disabled after we queried its state to be on. Fix this by protecting the power domain state tracking changes with a lock and holding this lock during error capturing.
Note that this still allows the case where we are halfway in enabling a power domain and still report it as disabled. This isn't a problem as we only want to avoid register accesses while the domain is off and that is now guaranteed. Signed-off-by: Imre Deak <[email protected]> [ Applies on top of "drm/i915: add intel_display_power_enabled_sw() for use in atomic ctx" ] --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/intel_display.c | 5 +++++ drivers/gpu/drm/i915/intel_pm.c | 5 +++++ 3 files changed, 11 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index cc06b9f..9e8d117 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -971,6 +971,7 @@ struct i915_power_domains { int power_well_count; struct mutex lock; + spinlock_t irq_lock; /* protects domain_use_count */ int domain_use_count[POWER_DOMAIN_NUM]; struct i915_power_well *power_wells; }; diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 464ae66..c7feee4 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -11368,6 +11368,7 @@ intel_display_capture_error_state(struct drm_device *dev) { drm_i915_private_t *dev_priv = dev->dev_private; struct intel_display_error_state *error; + unsigned long flags; int transcoders[] = { TRANSCODER_A, TRANSCODER_B, @@ -11386,6 +11387,8 @@ intel_display_capture_error_state(struct drm_device *dev) if (IS_HASWELL(dev) || IS_BROADWELL(dev)) error->power_well_driver = I915_READ(HSW_PWR_WELL_DRIVER); + spin_lock_irqsave(&dev_priv->power_domains.irq_lock, flags); + for_each_pipe(i) { error->pipe[i].power_domain_on = intel_display_power_enabled_sw(dev, POWER_DOMAIN_PIPE(i)); @@ -11441,6 +11444,8 @@ intel_display_capture_error_state(struct drm_device *dev) error->transcoder[i].vsync = I915_READ(VSYNC(cpu_transcoder)); } + spin_unlock_irqrestore(&dev_priv->power_domains.irq_lock, flags); + return error; } diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 311199c..00f6b34 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -5769,7 +5769,9 @@ void intel_display_power_get(struct drm_device *dev, for_each_power_well(i, power_well, BIT(domain), power_domains) __intel_power_well_get(dev, power_well); + spin_lock_irq(&power_domains->irq_lock); power_domains->domain_use_count[domain]++; + spin_unlock_irq(&power_domains->irq_lock); mutex_unlock(&power_domains->lock); } @@ -5787,7 +5789,9 @@ void intel_display_power_put(struct drm_device *dev, mutex_lock(&power_domains->lock); WARN_ON(!power_domains->domain_use_count[domain]); + spin_lock_irq(&power_domains->irq_lock); power_domains->domain_use_count[domain]--; + spin_unlock_irq(&power_domains->irq_lock); for_each_power_well_rev(i, power_well, BIT(domain), power_domains) __intel_power_well_put(dev, power_well); @@ -5871,6 +5875,7 @@ int intel_power_domains_init(struct drm_device *dev) struct drm_i915_private *dev_priv = dev->dev_private; struct i915_power_domains *power_domains = &dev_priv->power_domains; + spin_lock_init(&power_domains->irq_lock); mutex_init(&power_domains->lock); /* -- 1.8.4 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
