---

yaml --- r: 242311 b: refs/heads/master c: 00d70b1 h: refs/heads/master i: 242309: 6fede73 242307: c32c053 242303: 5d7b8e2 v: v3
git-mirror · Mar 23, 2011 · cd1ff14 · cd1ff14
1 parent 37f121e
commit cd1ff14
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Showing 2 changed files with 17 additions and 9 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 762237bb714b0cd93ce2405ccc891fadb405c26e
+refs/heads/master: 00d70b15125030391d17baab2c2f70f93b3339a6
diff --git a/trunk/drivers/gpu/drm/i915/intel_display.c b/trunk/drivers/gpu/drm/i915/intel_display.c
@@ -1516,8 +1516,10 @@ static void intel_enable_pipe(struct drm_i915_private *dev_priv, enum pipe pipe,
 
 	reg = PIPECONF(pipe);
 	val = I915_READ(reg);
-	val |= PIPECONF_ENABLE;
-	I915_WRITE(reg, val);
+	if (val & PIPECONF_ENABLE)
+		return;
+
+	I915_WRITE(reg, val | PIPECONF_ENABLE);
 	intel_wait_for_vblank(dev_priv->dev, pipe);
 }
 
@@ -1551,8 +1553,10 @@ static void intel_disable_pipe(struct drm_i915_private *dev_priv,
 
 	reg = PIPECONF(pipe);
 	val = I915_READ(reg);
-	val &= ~PIPECONF_ENABLE;
-	I915_WRITE(reg, val);
+	if ((val & PIPECONF_ENABLE) == 0)
+		return;
+
+	I915_WRITE(reg, val & ~PIPECONF_ENABLE);
 	intel_wait_for_pipe_off(dev_priv->dev, pipe);
 }
 
@@ -1575,8 +1579,10 @@ static void intel_enable_plane(struct drm_i915_private *dev_priv,
 
 	reg = DSPCNTR(plane);
 	val = I915_READ(reg);
-	val |= DISPLAY_PLANE_ENABLE;
-	I915_WRITE(reg, val);
+	if (val & DISPLAY_PLANE_ENABLE)
+		return;
+
+	I915_WRITE(reg, val | DISPLAY_PLANE_ENABLE);
 	intel_wait_for_vblank(dev_priv->dev, pipe);
 }
 
@@ -1607,8 +1613,10 @@ static void intel_disable_plane(struct drm_i915_private *dev_priv,
 
 	reg = DSPCNTR(plane);
 	val = I915_READ(reg);
-	val &= ~DISPLAY_PLANE_ENABLE;
-	I915_WRITE(reg, val);
+	if ((val & DISPLAY_PLANE_ENABLE) == 0)
+		return;
+
+	I915_WRITE(reg, val & ~DISPLAY_PLANE_ENABLE);
 	intel_flush_display_plane(dev_priv, plane);
 	intel_wait_for_vblank(dev_priv->dev, pipe);
 }