The performance went down from 64.7 to 51.4 fps in Valley and from 30.8 to 25.1
fps in Heaven.
Other games seem to have also a 10-25 % performance decrease.

Radeon HD 7970
4.11.0-1-amd-staging

fc99cb3c9edee3af773700cf7ebdc60dc02fcaba is the first bad commit
commit fc99cb3c9edee3af773700cf7ebdc60dc02fcaba
Author: Marek Olšák <marek.olsak@amd.com>
Date:   Wed Aug 23 16:07:35 2017 +0200

    radeonsi: get the raster config from AMDGPU on SI

    Not sure yet if we wanna do this on CIK and VI too.

    Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

:040000 040000 32e74450e5f5d9bc1cfb07fc7c700dd09ae54aed
01e5f531a26140e8983da5ab9250f73487a90627 M      src