Comment 22 for bug 1763189

Bisected:

af2405af07d168e2905f2ac9494d3a804a549f0f is the first bad commit
commit af2405af07d168e2905f2ac9494d3a804a549f0f
Author: Thierry Reding <email address hidden>
Date: Tue Jul 4 17:18:21 2017 +0200

    drm/fb-helper: Push down modeset lock into FB helpers

    Move the modeset locking from drivers into FB helpers.

    v2: Also handle intel_connector_add_to_fbdev.

    v3: Prevent race in intel_dp_mst with ->detect (Maarten)

    Cc: Maarten Lankhorst <email address hidden>
    Cc: Alex Deucher <email address hidden>
    Cc: Christian König <email address hidden>
    Tested-by: John Stultz <email address hidden>
    Signed-off-by: Thierry Reding <email address hidden> (v1)
    Reviewed-by: Maarten Lankhorst <email address hidden>
    Signed-off-by: Daniel Vetter <email address hidden>
    Link: http://patchwork.<email address hidden>