Boris Brezillon boris.brezillon@bootlin.com writes:
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: Eric Anholt eric@anholt.net