summaryrefslogtreecommitdiffstats
path: root/drivers/gpu
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/i915/intel_display.c24
1 files changed, 16 insertions, 8 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3bc6ab56cf8b..841f0397288b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/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);
}
OpenPOWER on IntegriCloud