[PATCH xf86-video-ati] Bail early from drm_wait_pending_flip if there's no pending flip

[michel@xxxxxxxxxxx (Michel Dänzer)]

From: Michel Dänzer <michel.daenzer@xxxxxxx>

No need to process any events in that case.

(Ported from amdgpu commit ca5eb9894fff153c0a1df7bdc4a4745713309e27)

Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---
 src/radeon_drm_queue.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/radeon_drm_queue.c b/src/radeon_drm_queue.c
index bf1650ea9..ea78e8e2b 100644
--- a/src/radeon_drm_queue.c
+++ b/src/radeon_drm_queue.c
@@ -284,7 +284,8 @@ void radeon_drm_wait_pending_flip(xf86CrtcPtr crtc)
 
     drmmode_crtc->wait_flip_nesting_level++;
 
-    while (!xorg_list_is_empty(&radeon_drm_flip_signalled)) {
+    while (drmmode_crtc->flip_pending &&
+	   !xorg_list_is_empty(&radeon_drm_flip_signalled)) {
 	e = xorg_list_first_entry(&radeon_drm_flip_signalled,
 				  struct radeon_drm_queue_entry, list);
 	radeon_drm_queue_handle_one(e);
-- 
2.19.0.rc1