[PATCH 1/5] drm/vblank: Fix return type for drm_vblank_count()

Dhinakaran Pandiyan dhinakaran.pandiyan at intel.com
Fri Jan 12 21:16:13 UTC 2018

drm_vblank_count() has a u32 type returning what is a 64-bit vblank count.
The effect of this is when drm_wait_vblank_ioctl() tries to widen the user
space requested vblank sequence using this clipped 32-bit count(when the
value is >= 2^32) as reference, the requested sequence remains a 32-bit
value and gets queued like that. However, the code that checks if the
requested sequence has passed compares this against the 64-bit vblank

Cc: Keith Packard <keithp at keithp.com>
Cc: Michel Dänzer <michel at daenzer.net>
Cc: Daniel Vetter <daniel at ffwll.ch>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
 drivers/gpu/drm/drm_vblank.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 32d9bcf5be7f..768a8e44d99b 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -271,7 +271,7 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
 	store_vblank(dev, pipe, diff, t_vblank, cur_vblank);
-static u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
+static u64 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
 	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];

More information about the Intel-gfx-trybot mailing list