(In reply to Alex Deucher from comment #14)
> Created attachment 137651 [details] [review] [review]
> patch to test
> 
> Can you try this patch and append amdgpu.force_atpx=1 to the kernel command
> line in grub?  Does it help?

Nope. To be precise: After invoking 'DRI_PRIME=1 glxinfo', the system crashed
before I was able to run dmesg (as in: the screen froze and it became
completely unresponsive). So that was not really an improvement. I'm gonna go
ahead and try the latest git head from that repo now, before I had only applied
your patch on top of c6bcaec0aa3e.