Quoting Chris Wilson (2020-06-11 13:30:37) > Since we have a precise start/end time for the sample, the actual time > the HW was read back is within that interval, and more likely closer to > the mean of the interval. Use the mean sample time when estimating the > vblank time. > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/drm_vblank.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c > index da7b0b0c1090..79a5461d3773 100644 > --- a/drivers/gpu/drm/drm_vblank.c > +++ b/drivers/gpu/drm/drm_vblank.c > @@ -710,15 +710,18 @@ drm_crtc_vblank_helper_get_vblank_timestamp_internal( > delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos), > mode->crtc_clock); > > + /* Estimate when the sample was taken */ > + stime += (etime - stime) >> 2; /2 != >>2 -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
