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@chris-wilson.co.uk Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Daniel Vetter daniel@ffwll.ch Cc: Michel Dänzer michel@daenzer.net Cc: Laurent Pinchart laurent.pinchart@ideasonboard.com Cc: Dave Airlie airlied@redhat.com, Cc: Mario Kleiner mario.kleiner.de@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;