drm/i915: Disable/enable planes as the first/last thing during modeset on gmch platforms

We already moved the plane disable/enable to happen as the first/last
thing on every other platforms. Follow suit with gmch platforms.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Frob drm_vblank_on conflict, as usual.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -4539,10 +4539,10 @@ static void valleyview_crtc_enable(struct drm_crtc *crtc)
 	intel_wait_for_vblank(dev_priv->dev, pipe);
 	intel_set_cpu_fifo_underrun_reporting(dev, pipe, true);
 
-	intel_crtc_enable_planes(crtc);
-
 	for_each_encoder_on_crtc(dev, crtc, encoder)
 		encoder->enable(encoder);
+
+	intel_crtc_enable_planes(crtc);
 }
 
 static void i9xx_crtc_enable(struct drm_crtc *crtc)
@@ -4575,10 +4575,10 @@ static void i9xx_crtc_enable(struct drm_crtc *crtc)
 	intel_wait_for_vblank(dev_priv->dev, pipe);
 	intel_set_cpu_fifo_underrun_reporting(dev, pipe, true);
 
-	intel_crtc_enable_planes(crtc);
-
 	for_each_encoder_on_crtc(dev, crtc, encoder)
 		encoder->enable(encoder);
+
+	intel_crtc_enable_planes(crtc);
 }
 
 static void i9xx_pfit_disable(struct intel_crtc *crtc)
@@ -4607,11 +4607,11 @@ static void i9xx_crtc_disable(struct drm_crtc *crtc)
 	if (!intel_crtc->active)
 		return;
 
+	intel_crtc_disable_planes(crtc);
+
 	for_each_encoder_on_crtc(dev, crtc, encoder)
 		encoder->disable(encoder);
 
-	intel_crtc_disable_planes(crtc);
-
 	intel_set_cpu_fifo_underrun_reporting(dev, pipe, false);
 	intel_disable_pipe(dev_priv, pipe);