Created attachment 100389 [details]
Copy of /sys/class/drm/card0/error

The last lines from dmesg after unfreeze:

[43209.531252] ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20131115/nsarguments-95)
[43209.531544] ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20131115/nsarguments-95)
[43728.912437] [drm] stuck on render ring
[43728.912443] [drm] GPU crash dump saved to /sys/class/drm/card0/error
[43728.912444] [drm] GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
[43728.912445] [drm] Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel
[43728.912446] [drm] drm/i915 developers can then reassign to the right component if it's not a kernel issue.
[43728.912448] [drm] The gpu crash dump is required to analyze gpu hangs, so please always attach it.
[43734.923280] ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20131115/nsarguments-95)
[43734.923404] ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20131115/nsarguments-95)

I'm attaching a copy of /sys/class/drm/card0/error

$ uname -a
Linux tgrabiec-laptop 3.13.0-27-generic #50-Ubuntu SMP Thu May 15 18:06:16 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

This is the second time I get such a freeze after installing recent upgrades from Ubuntu.

Thanks,
Tomek