Applying the following two cherry-picks to the xenial (Ubuntu-4.4.0-22.39) kernel solves the bug for my hardware,
git cherry-pick 4cd3991 git am 0001-drm-atomic-Remove-drm_atomic_connectors_for_crtc.patch # 14de6c4 does not apply cleanly, so use the attached patch
[For the mainline (v4.4.9) kernel, I have not figured out a minimal set of cherry-picks.]
Applying the following two cherry-picks to the xenial (Ubuntu- 4.4.0-22. 39) kernel solves the bug for my hardware,
git cherry-pick 4cd3991 atomic- Remove- drm_atomic_ connectors_ for_crtc. patch # 14de6c4 does not apply cleanly, so use the attached patch
git am 0001-drm-
[For the mainline (v4.4.9) kernel, I have not figured out a minimal set of cherry-picks.]