(In reply to tempel.julian from comment #68)
> I did it, but it stopped after hitting the two breakpoints the first time
> without me having moved the mouse at all. I suppose this isn't enough? Would
> it be possible to provide me with a short hint how to let it run longer?

Enter "continue" (or just "c") at the gdb prompt to continue, and wait for a
few breakpoint hits, to see if they're getting hit from multiple places.

Also, make sure debugging symbols are available for
/usr/lib/xorg/modules/drivers/amdgpu_drv.so (and ideally also for Xorg and its
modules), otherwise the backtraces are useless.