https://bugs.freedesktop.org/show_bug.cgi?id=88493
--- Comment #3 from Andy Furniss adf.lists@gmail.com --- (In reply to Andy Furniss from comment #2)
Maybe some pot luck is involved, maybe there is more than one issue - all the goods during the bisect were just tested once with boot from TV off.
Early testing - alternate booting a 10 times between "bad" kernel and a kernel on the commit before shows it's not pot luck. The kernel "before" always works and the one on the commit I bisected as bad always fails (TV off at boot) until it gets a prod via xrandr.
Seems almost anything will do, though just xrandr alone won't but any of
off then auto --set audio on --set dither on --mode 0x..
will get sound back.
Also reconfirmed that the above tricks do not work on head.