drm/i915: call drm_handle_vblank before finish_page_flip

... since finish_page_flip needs the vblank timestamp generated
in drm_handle_vblank. Somehow all the gmch platforms get it right,
but all the pch platform irq handlers get is wrong. Hooray for copy&
pasting!

Currently this gets papered over by a gross hack in finish_page_flip.
A second patch will remove that.

Note that without this, the new timestamp sanity checks in flip_test
occasionally get tripped up, hence the cc: stable tag.

Cc: stable@vger.kernel.org
Reviewed-by: mario.kleiner@tuebingen.mpg.de
Tested-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -698,12 +698,12 @@ static irqreturn_t ivybridge_irq_handler(DRM_IRQ_ARGS)
 			intel_opregion_gse_intr(dev);
 
 		for (i = 0; i < 3; i++) {
+			if (de_iir & (DE_PIPEA_VBLANK_IVB << (5 * i)))
+				drm_handle_vblank(dev, i);
 			if (de_iir & (DE_PLANEA_FLIP_DONE_IVB << (5 * i))) {
 				intel_prepare_page_flip(dev, i);
 				intel_finish_page_flip_plane(dev, i);
 			}
-			if (de_iir & (DE_PIPEA_VBLANK_IVB << (5 * i)))
-				drm_handle_vblank(dev, i);
 		}
 
 		/* check event from PCH */
@@ -785,6 +785,12 @@ static irqreturn_t ironlake_irq_handler(DRM_IRQ_ARGS)
 	if (de_iir & DE_GSE)
 		intel_opregion_gse_intr(dev);
 
+	if (de_iir & DE_PIPEA_VBLANK)
+		drm_handle_vblank(dev, 0);
+
+	if (de_iir & DE_PIPEB_VBLANK)
+		drm_handle_vblank(dev, 1);
+
 	if (de_iir & DE_PLANEA_FLIP_DONE) {
 		intel_prepare_page_flip(dev, 0);
 		intel_finish_page_flip_plane(dev, 0);
@@ -795,12 +801,6 @@ static irqreturn_t ironlake_irq_handler(DRM_IRQ_ARGS)
 		intel_finish_page_flip_plane(dev, 1);
 	}
 
-	if (de_iir & DE_PIPEA_VBLANK)
-		drm_handle_vblank(dev, 0);
-
-	if (de_iir & DE_PIPEB_VBLANK)
-		drm_handle_vblank(dev, 1);
-
 	/* check event from PCH */
 	if (de_iir & DE_PCH_EVENT) {
 		if (pch_iir & hotplug_mask)