From 632c6e4edef17c40bba3be67c980d959790d142f Mon Sep 17 00:00:00 2001 From: Ville Syrjälä Date: Tue, 10 Oct 2017 16:33:22 +0300 Subject: drm/vblank: Fix flip event vblank count MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Suggested-by: Daniel Vetter Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20171010133322.24029-1-ville.syrjala@linux.intel.com Reviewed-by: Daniel Vetter #irc --- drivers/gpu/drm/drm_vblank.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpu/drm') diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 70f2b9593edc..f14e6c92e332 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -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); } -- cgit v1.2.3