[PATCH 1/2] drm/i915: fix possible refcount leak when resetting forcewake

[Imre Deak <imre.deak@intel.com>]

If the timer putting the last forcewake refcount was pending and we
canceled it, we'll leak the corresponding forcewake and RPM references.

Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/intel_uncore.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index c90222d..389e235 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -299,9 +299,8 @@ static void vlv_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
-static void gen6_force_wake_timer(unsigned long arg)
+static void __gen6_force_wake_timer(struct drm_i915_private *dev_priv)
 {
-	struct drm_i915_private *dev_priv = (void *)arg;
 	unsigned long irqflags;
 
 	assert_device_not_suspended(dev_priv);
@@ -316,12 +315,20 @@ static void gen6_force_wake_timer(unsigned long arg)
 	intel_runtime_pm_put(dev_priv);
 }
 
+static void gen6_force_wake_timer(unsigned long arg)
+{
+	struct drm_i915_private *dev_priv = (void *)arg;
+
+	__gen6_force_wake_timer(dev_priv);
+}
+
 static void intel_uncore_forcewake_reset(struct drm_device *dev, bool restore)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	unsigned long irqflags;
 
-	del_timer_sync(&dev_priv->uncore.force_wake_timer);
+	if (del_timer_sync(&dev_priv->uncore.force_wake_timer))
+		__gen6_force_wake_timer(dev_priv);
 
 	/* Hold uncore.lock across reset to prevent any register access
 	 * with forcewake not set correctly
-- 
1.8.4