I have been experiencing the same problem periodically (the "[drm:i915_hangcheck_elapsed [i915]] *ERROR* Hangcheck timer elapsed... render ring idle" problem) on my computer. It ranges from 1 day to 3 weeks between crashes. I run Linux Mint 17 (or 17.1 or 17.2), and it has happened with various kernels, the latest being 3.19.0-26-generic. When it happens, my X session is a total loss. My mouse reflects movement, but the cursor never changes, and no windows refresh or can be interacted with. I can usually still switch to other consoles, which is how I was able to peruse logs after the last lockup.
My syslog snippet is attached. ** Attachment added: "syslog snippet" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1402331/+attachment/4453835/+files/i915_hangcheck_elapsed.log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1402331 Title: System will periodically lockup with [drm:i915_hangcheck_elapsed] *ERROR* Hangcheck timer elapsed... render ring idle To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1402331/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs