https://bugs.freedesktop.org/show_bug.cgi?id=66963
--- Comment #54 from Scias shining.scias@gmail.com --- I reverted to the "old" kernel + Comment 40 patch and it works now. I can't retrieve the git revision as I cleaned the sources but I cloned the drm-fixes-3.11 the 30/7 near 11:30 gmt.
I'll try different versions in between with Comment 40 patch to spot the change that cause it to not work anymore.