https://bugzilla.kernel.org/show_bug.cgi?id=90861
--- Comment #9 from Jon Arne Jørgensen jonjon.arnearne@gmail.com --- Finaly managed to get a clean bisect, this is the culprit:
commit f2c24b83ae90292d315aa7ac029c6ce7929e01aa Author: Maarten Lankhorst maarten.lankhorst@canonical.com Date: Wed Apr 2 17:14:48 2014 +0200
drm/ttm: flip the switch, and convert to dma_fence
Signed-off-by: Maarten Lankhorst maarten.lankhorst@canonical.com