https://bugs.freedesktop.org/show_bug.cgi?id=99275
--- Comment #9 from Reimar Imhof tuxuser@quantentunnel.de --- (In reply to Michel Dänzer from comment #7)
Any chance you can use git bisect to find the change between 4.8 and 4.9 which introduced the problem?
Sorry, I can't.
There should be a /usr/share/X11/xorg.conf.d/10-amdgpu.conf file which causes the amdgpu driver to be used automatically for GPUs controlled by the amdgpu kernel driver. If that file is missing, please report the problem to openSuse.
I filed a bug report at https://bugzilla.opensuse.org/show_bug.cgi?id=1018406