Comment 12 for bug 1504584

Created attachment 118873
requested dmesg with drm.debug=14

Possibly relevant excerpt:

[ 399.518389] [drm] stuck on render ring
[ 399.518686] [drm] GPU HANG: ecode 6:0:0xfeffffff, reason: Ring hung, action: reset
[ 399.518686] [drm] GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
[ 399.518686] [drm] Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel
[ 399.518687] [drm] drm/i915 developers can then reassign to the right component if it's not a kernel issue.
[ 399.518687] [drm] The gpu crash dump is required to analyze gpu hangs, so please always attach it.
[ 399.518687] [drm] GPU crash dump saved to /sys/class/drm/card0/error
[ 399.518699] [drm:i915_reset_and_wakeup] resetting chip
[ 399.518724] i915 0000:00:02.0: GEM idle failed, resume might fail
[ 399.518737] pci_pm_suspend(): i915_pm_suspend+0x0/0x50 [i915] returns -11
[ 399.518739] dpm_run_callback(): pci_pm_suspend+0x0/0x160 returns -11
[ 399.518741] PM: Device 0000:00:02.0 failed to suspend async: error -11
[ 399.518804] PM: Some devices failed to suspend, or early wake event detected

an edited /sys/class/drm/card0/error will be attached in a moment.