I have tried installing 2.19.0 from https://launchpad.net/~ubuntu-x-swat/+archive/x-updates but I still get these same hangs, so I believe the root of the cause lies somewhere in the kernel. Or it just was not solved in this version. I noticed that these bugs usually occur after the machine is resumed from S3 and is up and running for quite some time. If it's freshly booted, it seems to be running fine as far as this particular bug is concerned.
I'm attaching another Xorg log going along with another instance of: kernel: [42186.657190] [drm:i915_hangcheck_elapsed] *ERROR* Hangcheck timer elapsed... GPU hung kernel: [42186.657262] [drm] capturing error event; look for more information in /debug/dri/0/i915_error_state ** Attachment added: "Xorg.0.log.old" https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/993333/+attachment/3137725/+files/Xorg.0.log.old -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/993333 Title: [Sandybridge] Xorg freeze To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/993333/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs