The result of the bisect is
d4788db30a1a66255b592dd12613dda80c1443f7 is the first bad commit
commit d4788db30a1a66255b592dd12613dda80c1443f7
Author: Alex Deucher
Date:   Thu Feb 28 14:40:09 2013 -0500

    drm/radeon/evergreen: add support for golden register init

    Signed-off-by: Alex Deucher