https://bugs.freedesktop.org/show_bug.cgi?id=105725
--- Comment #10 from Marc Thomas marc@dragonfly.plus.com --- (In reply to Alex Deucher from comment #9)
It's possible that there are issues with gpio-amdpt and pinctrl-amd that lead to general system stability issues, but it should be noted the the gpio stuff in amdgpu is completely unrelated to those modules.
I think you're right - I still do get these warnings in 4.18.9 even with the modules blacklisted; just not all the time.
Interestingly I found the other warning I get from amdgpu_dm/amdgpu_dm_mst_types.c can be provoked by running "xcmddc -lv". It seems udevd does this during boot. See also bug 107456.