On Wed, Oct 18, 2017 at 04:50:19PM +0300, Ville Syrjälä wrote: > On Wed, Oct 18, 2017 at 09:07:47AM +0200, Andrzej Hajda wrote: > > Hi Ville, > > > > On 10.10.2017 15:33, Ville Syrjala wrote: > > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > > > 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@xxxxxxxxxxxxxxx > > > Cc: Daniel Vetter <daniel@xxxxxxxx> > > > Suggested-by: Daniel Vetter <daniel@xxxxxxxx> > > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/drm_vblank.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > 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; > > > > With this patch drm_crtc_arm_vblank_event calls > > drm_crtc_accurate_vblank_count, which requires get_vblank_timestamp > > callback, otherwise it issue WARN every time it is called. > > Argh! Maybe just remove the WARN then? Yeah tune it down to DRM_DEBUG_KMS or something similar I'd say. -Daniel > > > On the other side most of the users of drm_crtc_arm_vblank_event do not > > implement this callback. As a result one can observe multiple WARNs. > > It was observed on Exynos platform but grep shows it can affect many > > other platforms: > > > > $ git grep -l drm_crtc_arm_vblank_event drivers/gpu/drm/ > > drivers/gpu/drm/arm/hdlcd_crtc.c > > drivers/gpu/drm/arm/malidp_drv.c > > drivers/gpu/drm/drm_vblank.c > > drivers/gpu/drm/exynos/exynos_drm_crtc.c > > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c > > drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c > > drivers/gpu/drm/i915/intel_sprite.c > > drivers/gpu/drm/imx/ipuv3-crtc.c > > drivers/gpu/drm/mxsfb/mxsfb_crtc.c > > drivers/gpu/drm/nouveau/nouveau_display.c > > drivers/gpu/drm/pl111/pl111_display.c > > drivers/gpu/drm/sti/sti_crtc.c > > drivers/gpu/drm/stm/ltdc.c > > drivers/gpu/drm/sun4i/sun4i_crtc.c > > drivers/gpu/drm/tve200/tve200_display.c > > drivers/gpu/drm/vmwgfx/vmwgfx_kms.c > > drivers/gpu/drm/zte/zx_vou.c > > > > $ git grep -l get_vblank_timestamp drivers/gpu/drm/ > > drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c > > drivers/gpu/drm/drm_vblank.c > > drivers/gpu/drm/i915/i915_irq.c > > drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c > > drivers/gpu/drm/nouveau/nouveau_drm.c > > drivers/gpu/drm/radeon/radeon_drv.c > > drivers/gpu/drm/vc4/vc4_drv.c > > > > Regards > > Andrzej > > > > > e->event.crtc_id = crtc->base.id; > > > list_add_tail(&e->base.link, &dev->vblank_event_list); > > > } > > > > -- > Ville Syrjälä > Intel OTC -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
