drm/i915: Wait for vblank in hsw_enable_ips()

Now that the vblank wait is gone from intel_enable_primary_plane(),
hsw_enable_ips() needs to do the vblank wait itself.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -3734,17 +3734,17 @@ static void intel_disable_planes(struct drm_crtc *crtc)
 
 void hsw_enable_ips(struct intel_crtc *crtc)
 {
-	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+	struct drm_device *dev = crtc->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
 
 	if (!crtc->config.ips_enabled)
 		return;
 
-	/* We can only enable IPS after we enable a plane and wait for a vblank.
-	 * We guarantee that the plane is enabled by calling intel_enable_ips
-	 * only after intel_enable_plane. And intel_enable_plane already waits
-	 * for a vblank, so all we need to do here is to enable the IPS bit. */
+	/* We can only enable IPS after we enable a plane and wait for a vblank */
+	intel_wait_for_vblank(dev, crtc->pipe);
+
 	assert_plane_enabled(dev_priv, crtc->plane);
-	if (IS_BROADWELL(crtc->base.dev)) {
+	if (IS_BROADWELL(dev)) {
 		mutex_lock(&dev_priv->rps.hw_lock);
 		WARN_ON(sandybridge_pcode_write(dev_priv, DISPLAY_IPS_CONTROL, 0xc0000000));
 		mutex_unlock(&dev_priv->rps.hw_lock);

drivers/gpu/drm/i915/intel_sprite.c

@@ -696,10 +696,7 @@ intel_post_enable_primary(struct drm_crtc *crtc)
 	 * when going from primary only to sprite only and vice
 	 * versa.
 	 */
-	if (intel_crtc->config.ips_enabled) {
-		intel_wait_for_vblank(dev, intel_crtc->pipe);
-		hsw_enable_ips(intel_crtc);
-	}
+	hsw_enable_ips(intel_crtc);
 
 	mutex_lock(&dev->struct_mutex);
 	intel_update_fbc(dev);