Comment # 4 on bug 108031 from Alex Deucher

(In reply to Alex Deucher from comment #3)
> Remove amdgpu.dpm=1 from your kernel command line.  The default dpm
> implementation changed in 4.19.

and setting dpm=1 overrides that resulting in different behavior.  power
management is always enabled by default.  the dpm option is only for debugging
and switching between implementations for asics that contain multiple
implementations.