Created attachment 192471 [details] it is the output of command 'dmesg' I upgraded my Fedora21 kernel to 4.1.10-100.fc21.x86_64, after upgrade, when I startup my PC, sometimes, it looks like the gdm can't start. Because of that, I can't input my username\password to login. I used dmesg to check that, it looks like the bug occurs in gpu relevant drivers. I attached the dmesg.log below.
Please file new i915 bugs at https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel