drm/msm: Avoid rounding down to zero jiffies
authorRob Clark <robdclark@chromium.org>
Fri, 24 Mar 2023 22:00:13 +0000 (15:00 -0700)
committerDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Thu, 6 Apr 2023 17:29:40 +0000 (20:29 +0300)
commit4969bccd5f4e9d59e9aca7e873834be9519be013
tree781754e92bea4d1f441a460bc05830c7aff6c701
parentf1af066bcfd38daa9eee7195ef772dadaaa18520
drm/msm: Avoid rounding down to zero jiffies

If userspace asked for a timeout greater than zero, but less than a
jiffy, they clearly weren't planning on spinning.  So it is better
to round up to one.

This fixes an issue with supertuxkart that was (for some reason)
spinning on a gl sync with 1ms timeout.  CPU time for a demo lap
drops from:

  15.83user 20.98system 0:47.46elapsed 77%CPU

drops to:

  8.84user 2.30system 0:46.67elapsed 23%CPU

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/528725/
Link: https://lore.kernel.org/r/20230324220013.191795-1-robdclark@gmail.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
drivers/gpu/drm/msm/msm_drv.h