leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

drm/vblank: Fix flip event vblank count

Browse Source 
On machines where the vblank interrupt fires some time after the start
of vblank (or we just manage to race with the vblank interrupt handler)
we will currently stuff a stale vblank counter value into the flip event,
and thus we'll prematurely complete the flip.

Switch over to drm_crtc_accurate_vblank_count() to make sure we have an
up to date counter value, crucially also remember to add the +1 so that
the delayed vblank interrupt won't complete the flip prematurely.

Cc: stable@vger.kernel.org
Cc: Daniel Vetter <daniel@ffwll.ch>
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171010133322.24029-1-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel@ffwll.ch> #irc
This commit is contained in:
Ville Syrjälä 2017-10-10 16:33:22 +03:00
parent cccf4e3fe3
commit 632c6e4ede
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/gpu/drm/drm_vblank.c
View File

@ -869,7 +869,7 @@ void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
assert_spin_locked(&dev->event_lock);
e->pipe = pipe;
e->event.sequence = drm_vblank_count(dev, pipe);
e->event.sequence = drm_crtc_accurate_vblank_count(crtc) + 1;
e->event.crtc_id = crtc->base.id;
list_add_tail(&e->base.link, &dev->vblank_event_list);
}