[Tmmrn]

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.