Comment # 8 on bug 99275 from Reimar Imhof

Created attachment 128779 [details]
Xorg.0.log with activated Xorg amdgup driver

I found an Xorg amdgpu.conf file at the arch linux wiki:

Section "Device"
    Identifier "AMD"
    Driver "amdgpu"
EndSection

With this config the amdgpu Xorg driver gets loaded. But the kernel bug still
exists.