Comment # 105 on bug 102646 from magist3r

(In reply to reject5514 from comment #103)
> I have this problem on Archlinux 5.2.8-arch1-1-ARCH when connected 2
> monitors(1920x1080 @ 60Hz) and amdgpu.ppfeaturemask=0xffffffff option
> enabled. Patch didn't work for me.
> 
> My GPU is RX570.

Try this patch:
https://lists.freedesktop.org/archives/amd-gfx/2019-June/036022.html