https://bugzilla.kernel.org/show_bug.cgi?id=198123
--- Comment #49 from Daniel Vetter (daniel@ffwll.ch) --- Created attachment 277775 --> https://bugzilla.kernel.org/attachment.cgi?id=277775&action=edit insert huge sleep into lut load path
Maybe this helps in blowing up the race and perhaps shed some light here. Please test and report what happens.