https://bugs.freedesktop.org/show_bug.cgi?id=104391
--- Comment #6 from Andy Furniss adf.lists@gmail.com --- It seems that
HDMI has no sound after Panel power off/on
is the cause of the warnings.
I tested 4.18-wip, no sound of course but nothing in dmesg.
I then applied "HDMI has no sound after Panel power off/on" as a patch and get no sound + the warnings in dmesg on enabling the TV.
Remove the patch, then
git revert cfb071f7a9673109415d097125b3c12c16836acc
= working sound.