drm/i915: Rename intel_flush_display_plane to intel_flush_primary_plane

The intel_flush_primary_plane name actually tells us which plane
we're talking about.

Also reorganize the internals a bit and add a missing POSTING_READ()
to make sure the hardware has seen the changes by the time we
return from the function.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -1812,13 +1812,13 @@ static void intel_disable_pipe(struct drm_i915_private *dev_priv,
  * Plane regs are double buffered, going from enabled->disabled needs a
  * trigger in order to latch.  The display address reg provides this.
  */
-void intel_flush_display_plane(struct drm_i915_private *dev_priv,
-				      enum plane plane)
+void intel_flush_primary_plane(struct drm_i915_private *dev_priv,
+			       enum plane plane)
 {
-	if (dev_priv->info->gen >= 4)
-		I915_WRITE(DSPSURF(plane), I915_READ(DSPSURF(plane)));
-	else
-		I915_WRITE(DSPADDR(plane), I915_READ(DSPADDR(plane)));
+	u32 reg = dev_priv->info->gen >= 4 ? DSPSURF(plane) : DSPADDR(plane);
+
+	I915_WRITE(reg, I915_READ(reg));
+	POSTING_READ(reg);
 }
 
 /**
@@ -1848,7 +1848,7 @@ static void intel_enable_plane(struct drm_i915_private *dev_priv,
 		return;
 
 	I915_WRITE(reg, val | DISPLAY_PLANE_ENABLE);
-	intel_flush_display_plane(dev_priv, plane);
+	intel_flush_primary_plane(dev_priv, plane);
 	intel_wait_for_vblank(dev_priv->dev, pipe);
 }
 
@@ -1876,7 +1876,7 @@ static void intel_disable_plane(struct drm_i915_private *dev_priv,
 		return;
 
 	I915_WRITE(reg, val & ~DISPLAY_PLANE_ENABLE);
-	intel_flush_display_plane(dev_priv, plane);
+	intel_flush_primary_plane(dev_priv, plane);
 	intel_wait_for_vblank(dev_priv->dev, pipe);
 }
 

drivers/gpu/drm/i915/intel_drv.h

@@ -811,7 +811,7 @@ bool intel_sdvo_init(struct drm_device *dev, uint32_t sdvo_reg, bool is_sdvob);
 
 /* intel_sprite.c */
 int intel_plane_init(struct drm_device *dev, enum pipe pipe, int plane);
-void intel_flush_display_plane(struct drm_i915_private *dev_priv,
+void intel_flush_primary_plane(struct drm_i915_private *dev_priv,
 			       enum plane plane);
 void intel_plane_restore(struct drm_plane *plane);
 void intel_plane_disable(struct drm_plane *plane);

drivers/gpu/drm/i915/intel_pm.c

@@ -4773,7 +4773,7 @@ static void g4x_disable_trickle_feed(struct drm_device *dev)
 		I915_WRITE(DSPCNTR(pipe),
 			   I915_READ(DSPCNTR(pipe)) |
 			   DISPPLANE_TRICKLE_FEED_DISABLE);
-		intel_flush_display_plane(dev_priv, pipe);
+		intel_flush_primary_plane(dev_priv, pipe);
 	}
 }
 

drivers/gpu/drm/i915/intel_tv.c

@@ -1094,7 +1094,7 @@ static void intel_tv_mode_set(struct intel_encoder *encoder)
 		unsigned int xsize, ysize;
 		/* Pipe must be off here */
 		I915_WRITE(dspcntr_reg, dspcntr & ~DISPLAY_PLANE_ENABLE);
-		intel_flush_display_plane(dev_priv, intel_crtc->plane);
+		intel_flush_primary_plane(dev_priv, intel_crtc->plane);
 
 		/* Wait for vblank for the disable to take effect */
 		if (IS_GEN2(dev))
@@ -1123,7 +1123,7 @@ static void intel_tv_mode_set(struct intel_encoder *encoder)
 
 		I915_WRITE(pipeconf_reg, pipeconf);
 		I915_WRITE(dspcntr_reg, dspcntr);
-		intel_flush_display_plane(dev_priv, intel_crtc->plane);
+		intel_flush_primary_plane(dev_priv, intel_crtc->plane);
 	}
 
 	j = 0;