On 04/14/2015 08:36 PM, Chris Wilson wrote: > On Tue, Apr 14, 2015 at 08:22:20PM +0200, Mario Kleiner wrote: >> On 04/05/2015 05:40 PM, Chris Wilson wrote: >>> 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; >>> >> >> It would be good to have some DRM_DEBUG output for the skip-the-wait >> case as well, so one can still follow from dmesg output when a >> client does a drmWaitVblank call even if it is only a query. > > We still have DRM_DEBUG("returning %d to client"), as well as the > drmIoctl:DRM_DEBUG(ioctl->name), is that not sufficient? > -Chris >
Oh right, that's good enough. Maybe add "on crtc %d" to that DRM_DEBUG, to make it unambiguous for which crtc some count is returned? -mario