(In reply to Mathias Tillman from comment #11)
> No luck here I'm afraid - I'm having a hard time reproducing it during
> normal desktop usage (with or without the patch), but it did lockup while
> running Unigine Valley.

Assuming you can still access the box over the network after the lockup then
please provide the output of the following as root:

cat /sys/kernel/debug/dri/0/amdgpu_fence_info
hexdump -s 0x14fc -n 4 /sys/kernel/debug/dri/0/amdgpu_regs