Commits
Eugeni Dodonov committed aa464191869
drm/i915: enable plain RC6 on Sandy Bridge by default This is yet another chapter in the ongoing saga of bringing RC6 to Sandy Bridge machines by default. Now that we have discovered that RC6 issues are triggered by RC6+ state, let's try to disable it by default. Plain RC6 is the one responsible for most energy savings, and so far it haven't given any problems - at least, none we are aware of. So with this, when i915_enable_rc6=-1 (e.g., the default value), we'll attempt to enable plain RC6 only on SNB. For Ivy Bridge, the behavior stays the same as always - we enable both RC6 and deep RC6. Note that while this exact patch does not has explicit tested-by's, the equivalent settings were fixed in 3.3 kernel by a smaller patch. And it has also received considerable testing through Canonical RC6 task-force testing at https://wiki.ubuntu.com/Kernel/PowerManagementRC6. Up to date, it looks like all the known issues are gone. v2: improve description and reference a couple of open bugs related to RC6 which seem to be fixed with this change. References: https://bugs.freedesktop.org/show_bug.cgi?id=41682 References: https://bugs.freedesktop.org/show_bug.cgi?id=38567 References: https://bugs.freedesktop.org/show_bug.cgi?id=44867 Acked-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>