Comment # 2 on bug 111487 from bzz

after some time following errors appear in dmesg:

[  488.913338] [drm:drm_atomic_helper_wait_for_flip_done [drm_kms_helper]]
*ERROR* [CRTC:56:crtc-0] flip_done timed out
[  970.551486] [drm:drm_atomic_helper_wait_for_dependencies [drm_kms_helper]]
*ERROR* [CRTC:56:crtc-0] flip_done timed out