Avoid adding to the waitqueue and reprobing the current vblank if the
caller is only querying the current vblank sequence and timestamp and
so we would return immediately.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: Michel Dänzer <michel at daenzer.net>
Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Cc: Dave Airlie <airlied at redhat.com>,
Cc: Mario Kleiner <mario.kleiner.de at gmail.com>
---
drivers/gpu/drm/drm_irq.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 6f5dc18779e2..ba80b51b4b00 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -1617,14 +1617,16 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
vblwait->request.sequence = seq + 1;
}
- DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
- vblwait->request.sequence, crtc);
- vblank->last_wait = vblwait->request.sequence;
- DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
- (((drm_vblank_count(dev, crtc) -
- vblwait->request.sequence) <= (1 << 23)) ||
- !vblank->enabled ||
- !dev->irq_enabled));
+ if (vblwait->request.sequence != seq) {
+ DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
+ vblwait->request.sequence, crtc);
+ vblank->last_wait = vblwait->request.sequence;
+ DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
+ (((drm_vblank_count(dev, crtc) -
+ vblwait->request.sequence) <= (1 << 23)) ||
+ !vblank->enabled ||
+ !dev->irq_enabled));
+ }
if (ret != -EINTR) {
struct timeval now;
--
2.1.4
