Bug#945055: linux: CPU runs at considerably higher temperatures

[Christoph Anton Mitterer <calestyo@scientia.net>]

Hey.

According to https://gitlab.freedesktop.org/drm/intel/issues/953 the
bug was introduced by:
drm/i915/gen8+: Add RC6 CTX corruption WA (d4360736a7c0a6326e3bbdf7d41181f6ed03d9a6)

which, AFAIU, is actually a security fix.


There seem to be some patches, but not sure when they'll be "final" (if
ever)... without opening the security issue again.


Also this would just fix my imminent showstopper of Cinnamon running at
extreme temperatures when being effectively idle.

As my test series shows the following issues likely remain:
- Cinnamon performs noticeably worse with video playback than GNOME
  even under 5.2 (where the offending commit isn't there)
- vaapi performs than xv (which I guess it shouldn't)
- intel_pstate makes the system hotter to.


Thanks,
Chris.