(In reply to Nicholas Kazlauskas from comment #9)
> The patchset from:
> 
> https://patchwork.freedesktop.org/patch/260799/
> 
> ...will likely resolve this issue.
> 
> It has been merged into amd-staging-drm-next branch at:
> 
> https://cgit.freedesktop.org/~agd5f/linux

Tried amd-staging-drm-next, it works!