drm: use page flip event to signal flip completion

We don't actually know which frame number the flip will complete on, so
userspace needs a specific flip notification to tell it when the last flip
completed.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Kristian Høgsberg <krh@bitplanet.net>

drivers/gpu/drm/drm_crtc.c

@@ -2527,7 +2527,7 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
 			goto out;
 		}
 
-		e->event.base.type = DRM_EVENT_VBLANK;
+		e->event.base.type = DRM_EVENT_FLIP_COMPLETE;
 		e->event.base.length = sizeof e->event;
 		e->event.user_data = page_flip->user_data;
 		e->base.event = &e->event.base;

include/drm/drm.h

@@ -718,6 +718,7 @@ struct drm_event {
 };
 
 #define DRM_EVENT_VBLANK 0x01
+#define DRM_EVENT_FLIP_COMPLETE 0x02
 
 struct drm_event_vblank {
 	struct drm_event base;