drm_atomic_helper_wait_for_vblanks() assumes the CRTC will continuously generate VBLANK events and the vblank counter will keep increasing. While this work for a regular pipeline, it doesn't when you have the CRTC is feeding the transposer block, because this block works in oneshot mode, and, by the time we reach drm_atomic_helper_wait_for_vblanks() the only VBLANK event might have already been sent and the VBLANK counter will stay unchanged, thus triggering a timeout.
Luckily, we can replace the drm_atomic_helper_wait_for_vblanks() call by drm_atomic_helper_wait_for_flip_done() because the only thing we want to check when calling drm_atomic_helper_wait_for_vblanks() from vc4_atomic_complete_commit() is that new FBs are in use and the old ones can be safely released.
Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com Reviewed-by: Liviu Dudau liviu.dudau@arm.com Reviewed-by: Eric Anholt eric@anholt.net --- Changes in v3: - Add Eric's and Liviu's R-b
Changes in v2: - None --- drivers/gpu/drm/vc4/vc4_kms.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c index 8a411e5f8776..91239b0a4fa0 100644 --- a/drivers/gpu/drm/vc4/vc4_kms.c +++ b/drivers/gpu/drm/vc4/vc4_kms.c @@ -153,18 +153,9 @@ vc4_atomic_complete_commit(struct drm_atomic_state *state)
drm_atomic_helper_commit_modeset_enables(dev, state);
- /* Make sure that drm_atomic_helper_wait_for_vblanks() - * actually waits for vblank. If we're doing a full atomic - * modeset (as opposed to a vc4_update_plane() short circuit), - * then we need to wait for scanout to be done with our - * display lists before we free it and potentially reallocate - * and overwrite the dlist memory with a new modeset. - */ - state->legacy_cursor_update = false; - drm_atomic_helper_commit_hw_done(state);
- drm_atomic_helper_wait_for_vblanks(dev, state); + drm_atomic_helper_wait_for_flip_done(dev, state);
drm_atomic_helper_cleanup_planes(dev, state);