From d19dc2101a3fc510eea6dc7cc88f30e9ffc0fa6a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 17 Dec 2014 16:38:33 +0200 Subject: [PATCH] drm/i915: Kill check_power_well() calls MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit pps_{lock,unlock}() call intel_display_power_{get,put}() outside pps_mutes to avoid deadlocks with the power_domain mutex. In theory during aux transfers we should usually have the relevant power domain references already held by some higher level code, so this should not result in much overhead (exception being userspace i2c-dev access). However thanks to the check_power_well() calls in intel_display_power_{get/put}() we end up doing a few Punit reads for each aux transfer. Obviously doing this for each byte transferred via i2c-over-aux is not a good idea. I can't think of a good way to keep check_power_well() while eliminating the overhead, so let's just remove check_power_well() entirely. Credit goes to Jani for figuring this out, assuming it helps :) Cc: Egbert Eich Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86201 Signed-off-by: Ville Syrjälä --- drivers/gpu/drm/i915/intel_runtime_pm.c | 27 --------------------------- 1 file changed, 27 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index 6aa3a81..39e1b07 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -615,29 +615,6 @@ static void chv_pipe_power_well_disable(struct drm_i915_private *dev_priv, vlv_power_sequencer_reset(dev_priv); } -static void check_power_well_state(struct drm_i915_private *dev_priv, - struct i915_power_well *power_well) -{ - bool enabled = power_well->ops->is_enabled(dev_priv, power_well); - - if (power_well->always_on || !i915.disable_power_well) { - if (!enabled) - goto mismatch; - - return; - } - - if (enabled != (power_well->count > 0)) - goto mismatch; - - return; - -mismatch: - I915_STATE_WARN(1, "state mismatch for '%s' (always_on %d hw state %d use-count %d disable_power_well %d\n", - power_well->name, power_well->always_on, enabled, - power_well->count, i915.disable_power_well); -} - /** * intel_display_power_get - grab a power domain reference * @dev_priv: i915 device instance @@ -669,8 +646,6 @@ void intel_display_power_get(struct drm_i915_private *dev_priv, power_well->ops->enable(dev_priv, power_well); power_well->hw_enabled = true; } - - check_power_well_state(dev_priv, power_well); } power_domains->domain_use_count[domain]++; @@ -709,8 +684,6 @@ void intel_display_power_put(struct drm_i915_private *dev_priv, power_well->hw_enabled = false; power_well->ops->disable(dev_priv, power_well); } - - check_power_well_state(dev_priv, power_well); } mutex_unlock(&power_domains->lock); -- 2.0.4