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@xxxxxxxxxx/ Fixes: d39e48ca80c0 ("drm/atomic-helper: Set fence deadline for vblank") Cc: Rob Clark <robdclark@xxxxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Cc: Maxime Ripard <mripard@xxxxxxxxxx> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> Reported-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Tested-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> # test patch only Cc: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> --- 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; + if (drm_crtc_next_vblank_start(crtc, &v)) continue; -- 2.40.0
