[Intel-gfx] i915: Regression: +4W in idle power use on Macbook Pro 15 (late 2013)

[Daniel Vetter]

On Tue, Aug 26, 2014 at 4:57 PM, Eric Rannaud <eric.rannaud at gmail.com> wrote:
> On Tue, Aug 26, 2014 at 6:38 AM, Eric Rannaud <eric.rannaud at gmail.com> wrote:
>> Could the FBC commit somehow also disable RC6, or similar?
>
> I just tried these kernel arguments with no significant effect on
> power consumption (i.e. still around 11W in idle, instead of under
> 7W):
>         i915.enable_rc6=1 i915.lvds_downclock=1 pcie_aspm=force
>
> Forcing FBC with i915.enable_fbc=1 brings the idle power consumption
> back to under 7W, however.
> This is all on 3.15.4-ARCH-00041-gf4db98240ac2.

Any significant changes in package C state as reported in powertop?
Indeed fairly impressive how much fbc saves here ...
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch