| Message ID | 20230405081650.797972-1-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/atomic-helper: Don't set deadline for modesets | expand |
On Wed, Apr 05, 2023 at 10:16:50AM +0200, Daniel Vetter wrote: > If the crtc is being switched on or off then the semantics of > computing the timestampe of the next vblank is somewhat ill-defined. > And indeed, the code splats with a warning in the timestamp > computation code. Specifically it hits the check to make sure that > atomic drivers have full set up the timing constants in the drm_vblank > structure, and that's just not the case before the crtc is actually > on. > > For robustness it seems best to just not set deadlines for modesets. > > Link: https://lore.kernel.org/dri-devel/dfc21f18-7e1e-48f0-c05a-d659b9c90b91@linaro.org/ > Fixes: d39e48ca80c0 ("drm/atomic-helper: Set fence deadline for vblank") > Cc: Rob Clark <robdclark@chromium.org> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > Cc: Maxime Ripard <mripard@kernel.org> > Cc: Thomas Zimmermann <tzimmermann@suse.de> > Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # test patch only > Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> > --- > drivers/gpu/drm/drm_atomic_helper.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > index f21b5a74176c..6640d80d84f3 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -1528,6 +1528,9 @@ static void set_fence_deadline(struct drm_device *dev, > for_each_new_crtc_in_state (state, crtc, new_crtc_state, i) { > ktime_t v; > > + if (drm_atomic_crtc_needs_modeset(new_crtc_state)) > + continue; Should this stuff also be skipped when !new_crtc_state->active? I didn't actually check what drm_crtc_next_vblank_start() ends up doing in that case. > + > if (drm_crtc_next_vblank_start(crtc, &v)) > continue; > > -- > 2.40.0
On Wed, Apr 05, 2023 at 03:25:15PM +0300, Ville Syrjälä wrote: > On Wed, Apr 05, 2023 at 10:16:50AM +0200, Daniel Vetter wrote: > > If the crtc is being switched on or off then the semantics of > > computing the timestampe of the next vblank is somewhat ill-defined. > > And indeed, the code splats with a warning in the timestamp > > computation code. Specifically it hits the check to make sure that > > atomic drivers have full set up the timing constants in the drm_vblank > > structure, and that's just not the case before the crtc is actually > > on. > > > > For robustness it seems best to just not set deadlines for modesets. > > > > Link: https://lore.kernel.org/dri-devel/dfc21f18-7e1e-48f0-c05a-d659b9c90b91@linaro.org/ > > Fixes: d39e48ca80c0 ("drm/atomic-helper: Set fence deadline for vblank") > > Cc: Rob Clark <robdclark@chromium.org> > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > > Cc: Maxime Ripard <mripard@kernel.org> > > Cc: Thomas Zimmermann <tzimmermann@suse.de> > > Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > > Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # test patch only > > Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> > > --- > > drivers/gpu/drm/drm_atomic_helper.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > > index f21b5a74176c..6640d80d84f3 100644 > > --- a/drivers/gpu/drm/drm_atomic_helper.c > > +++ b/drivers/gpu/drm/drm_atomic_helper.c > > @@ -1528,6 +1528,9 @@ static void set_fence_deadline(struct drm_device *dev, > > for_each_new_crtc_in_state (state, crtc, new_crtc_state, i) { > > ktime_t v; > > > > + if (drm_atomic_crtc_needs_modeset(new_crtc_state)) > > + continue; > > Should this stuff also be skipped when !new_crtc_state->active? > I didn't actually check what drm_crtc_next_vblank_start() ends > up doing in that case. Uh yes, I'll spin v2. -Daniel > > > + > > if (drm_crtc_next_vblank_start(crtc, &v)) > > continue; > > > > -- > > 2.40.0 > > -- > Ville Syrjälä > Intel
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index f21b5a74176c..6640d80d84f3 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -1528,6 +1528,9 @@ static void set_fence_deadline(struct drm_device *dev, for_each_new_crtc_in_state (state, crtc, new_crtc_state, i) { ktime_t v; + if (drm_atomic_crtc_needs_modeset(new_crtc_state)) + continue; + if (drm_crtc_next_vblank_start(crtc, &v)) continue;
If the crtc is being switched on or off then the semantics of computing the timestampe of the next vblank is somewhat ill-defined. And indeed, the code splats with a warning in the timestamp computation code. Specifically it hits the check to make sure that atomic drivers have full set up the timing constants in the drm_vblank structure, and that's just not the case before the crtc is actually on. For robustness it seems best to just not set deadlines for modesets. Link: https://lore.kernel.org/dri-devel/dfc21f18-7e1e-48f0-c05a-d659b9c90b91@linaro.org/ Fixes: d39e48ca80c0 ("drm/atomic-helper: Set fence deadline for vblank") Cc: Rob Clark <robdclark@chromium.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # test patch only Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> --- drivers/gpu/drm/drm_atomic_helper.c | 3 +++ 1 file changed, 3 insertions(+)