https://bugs.freedesktop.org/show_bug.cgi?id=91278
--- Comment #42 from Alex Deucher alexdeucher@gmail.com --- (In reply to Mathias Tillman from comment #41)
Just tried it again with the latest drm-next-4.4 and the kernel parameters amdgpu.enable_scheduler=0 amdgpu.vm_debug=1 amdgpu.enable_semaphores=1.
I don't think forcing semaphores will work on tonga/fiji since there were disabled in the code a while ago due to hw bugs.