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| author | Mario Kleiner <mario.kleiner.de@gmail.com> | 2014-03-19 09:02:11 (GMT) |
|---|---|---|
| committer | Ben Skeggs <bskeggs@redhat.com> | 2014-03-26 04:08:23 (GMT) |
| commit | 6c3252bc83155ae69d78fefdc7458aa64d8a87db (patch) | |
| tree | 4e8e3e270a4caef78068470262c2d8347b4ada01 /drivers/gpu/drm/nouveau/nouveau_display.c | |
| parent | dcd9262b3baf881285e9e0fd5459d54723cc992e (diff) | |
| download | linux-6c3252bc83155ae69d78fefdc7458aa64d8a87db.tar.xz | |
drm/nouveau: fix small thinko in vblank timestamping.
*hpos horizontal scanout position doesn't need to be corrected
to count the pixels between hactive end and htotal negative.
That is only needed for *vpos to count lines until end of
vblank for the vblank timestamping.
Use hpos as is without correction.
Removes occassional spikes in timestamps of up to 1 scanline
duration, thereby improves accuracy to about +/- 2 usecs instead
of +/- 12 usecs, wrt. true onset time as measured with high
precision equipment on NV-A5.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/nouveau/nouveau_display.c')
| -rw-r--r-- | drivers/gpu/drm/nouveau/nouveau_display.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c index db19a56..b1547b0 100644 --- a/drivers/gpu/drm/nouveau/nouveau_display.c +++ b/drivers/gpu/drm/nouveau/nouveau_display.c @@ -105,7 +105,7 @@ nouveau_display_scanoutpos_head(struct drm_crtc *crtc, int *vpos, int *hpos, if (retry) ndelay(crtc->linedur_ns); } while (retry--); - *hpos = calc(args.hblanks, args.hblanke, args.htotal, args.hline); + *hpos = args.hline; *vpos = calc(args.vblanks, args.vblanke, args.vtotal, args.vline); if (stime) *stime = ns_to_ktime(args.time[0]); if (etime) *etime = ns_to_ktime(args.time[1]); |