Comment # 36 on bug 110865 from tempel.julian@gmail.com

(In reply to Dieter Nützel from comment #28)
> I've tried solving the flicker with both fixes (sent by magist3r) from this
> bug
> 
> Bug 102646 - Screen flickering under amdgpu-experimental [buggy auto power
> profile]
> https://bugs.freedesktop.org/show_bug.cgi?id=102646
> 
> But no success.

Have you also applied Ahzo's patch, just in case?