[Intel-gfx] [PATCH 16/19] drm/i915: sanity check power well sw state against hw state

[Imre Deak]

Suggested by Daniel.

Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index e81e7de..21ccf89 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5338,6 +5338,24 @@ static void hsw_power_well_disable(struct drm_i915_private *dev_priv,
 	hsw_enable_package_c8(dev_priv);
 }
 
+static void check_power_well_state(struct drm_i915_private *dev_priv,
+				   struct i915_power_well *power_well)
+{
+	bool enabled;
+
+	if (!power_well->ops->is_enabled)
+		return;
+
+	enabled = power_well->ops->is_enabled(dev_priv, power_well);
+
+	if (enabled != (power_well->count > 0 || !i915.disable_power_well)) {
+		DRM_ERROR("state mismatch for '%s' (hw state %d use-count %d disable_power_well %d\n",
+			  power_well->name, enabled, power_well->count,
+			  i915.disable_power_well);
+		WARN_ON(1);
+	}
+}
+
 void intel_display_power_get(struct drm_i915_private *dev_priv,
 			     enum intel_display_power_domain domain)
 {
@@ -5349,9 +5367,14 @@ void intel_display_power_get(struct drm_i915_private *dev_priv,
 
 	mutex_lock(&power_domains->lock);
 
-	for_each_power_well(i, power_well, BIT(domain), power_domains)
-		if (!power_well->count++ && power_well->ops->enable)
+	for_each_power_well(i, power_well, BIT(domain), power_domains) {
+		if (!power_well->count++ && power_well->ops->enable) {
+			DRM_DEBUG_KMS("enabling %s\n", power_well->name);
 			power_well->ops->enable(dev_priv, power_well);
+		}
+
+		check_power_well_state(dev_priv, power_well);
+	}
 
 	power_domains->domain_use_count[domain]++;
 
@@ -5376,8 +5399,12 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
 		WARN_ON(!power_well->count);
 
 		if (!--power_well->count && power_well->ops->disable &&
-		    i915.disable_power_well)
+		    i915.disable_power_well) {
+			DRM_DEBUG_KMS("disabling %s\n", power_well->name);
 			power_well->ops->disable(dev_priv, power_well);
+		}
+
+		check_power_well_state(dev_priv, power_well);
 	}
 
 	mutex_unlock(&power_domains->lock);
-- 
1.8.4