https://bugzilla.kernel.org/show_bug.cgi?id=90741
--- Comment #1 from Gustaw Smolarczyk wielkiegie@gmail.com --- I have managed to bisect this regression:
f2c24b83ae90292d315aa7ac029c6ce7929e01aa is the first bad commit 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
:040000 040000 634b9d842856f9a253b8250b6b61423a8b19bf7d 82569dbc605b725ecefac7457b25599158af5fb6 M drivers :040000 040000 6ff7fd43b2671ac388b81ec3c9ab47f4a2d39162 0c9d3986f193c83b952b05e7ec1f1c777a44e88e M include
I am not familiar with the kernel code so I cannot say whether it's a real regression or is just a problem with a userspace.