Comment # 2 on bug 97594 from Arek Ruśniak

sorry for lack of description

It's Alex's drm-next-4.9-wip branch.

First bad commit: 
commit  deca1d1f16eebfa0d070eed50a221e01cf716ee0
author  Tom St Denis <tom.stdenis@amd.com>

drm/amd/amdgpu: Add GRBM lock to various SI functions
Add missing lock around SE/SH/INSTANCE selections.