Since mesa 11, most of the times game loading crashes, either with a freeze or
a blizzard error window.
I use a Sandy Bridge IGP and a Radeon HD 7970 with DRI_PRIME, using dri3 and
wine with d3dadapter (so it uses mesa d3d state tracker).

Sometimes, an error is printed in kernel messages:
[ 7481.648047] radeon 0000:01:00.0: GPU fault detected: 146 0x0feb6014
[ 7481.648051] radeon 0000:01:00.0:   VM_CONTEXT1_PROTECTION_FAULT_ADDR  
0x0000EEFF
[ 7481.648052] radeon 0000:01:00.0:   VM_CONTEXT1_PROTECTION_FAULT_STATUS
0x0B060014

I have bisected and the issue seems to come from

commit 719f124620d3c9b4d6ce14db3dbfc7af05626e5b
Author: Axel Davy <axel.davy@ens.fr>
Date:   Sun Aug 9 19:06:01 2015 +0200

    st/nine: Catch setting the same shader

    This is quite rare that an app does set again
    the same shaders, but it isn't an expensive check
    either.

    Signed-off-by: Axel Davy <axel.davy@ens.fr>

How can I provide more debugging info so we can find the specific issue in the
commit ?