https://bugzilla.kernel.org/show_bug.cgi?id=205049
--- Comment #4 from Alex Deucher (alexdeucher@gmail.com) --- Just append: amdgpu.ppfeaturemask=0xffff3fff to the end of the kernel command line in grub. Replace 0xffff3fff with 0xfffdbfff to try the other option. Repeat with 0xfffd3fff if necessary.