On a different node, I am disappointed that kernel developers haven't been able to solve this bug https://bugzilla.kernel.org/show_bug.cgi?id=48721 since last 2 months. I am an avid linux fan but this drives me crazy.
Do you boot with some power saving parameters like i915.rc6=7? If so, remove ALL of them and try again.
Is that the HM65 chipset in that notebook? I have a Ivy Bridge CPU on the HM77 chipset and I had initially some problems with the scaling not working correctly but after a few reboots cpupower has worked without ever having a problem anymore...
http://sprunge.us/TEPU is my hardware and this bug is produced only on random reboots/resumes. Earlier, I had i915.rc6=7 in my kernel parameter, but I have removed it now. I rebooted and no issues but as I said, this issue happens on random reboots/suspend-resumes so I can never be sure.
I have googled a bit about these or similar issues and there are some other maybe or maybe not related bugs in the kernel bugzilla. One was about the GPU randomly not entering the low power states and there a developer commented how many of those power saving parameters are disabled for a good reason and that you shouldn't even report bugs when you have nondefault settings.
There are still a lot of weird bugs for example i915.rc6=1 would produce the problem with the GPU not even entering the (lower) power states that the default settings would.
Is that the HM65 chipset in that notebook? I have a Ivy Bridge CPU on the HM77 chipset and I had initially some problems with the scaling not working correctly but after a few reboots cpupower has worked without ever having a problem anymore...