https://bugs.freedesktop.org/show_bug.cgi?id=55829
--- Comment #8 from meng mengmeng.meng@intel.com --- It's not libdrm regression. It's xf86_video_intel regression, and bisected show that xf86_video_intel 1675f441049d559d891fe378e437c12db21df9e7 is the first bad commit.
commit 1675f441049d559d891fe378e437c12db21df9e7 Author: Chris Wilson chris@chris-wilson.co.uk Date: Wed Jun 6 12:55:13 2012 +0100 uxa/dri: Transfer reference of the new_back buffer to the flip_chain