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

[Eric Rannaud]

On Wed, Aug 27, 2014 at 2:17 AM, Ville Syrjälä
<ville.syrjala at linux.intel.com> wrote:
>> Not that I can tell.
>>     Powertop report with FBC: http://pastebin.com/5qfJKpTQ
>>     Without FBC: http://pastebin.com/NaYkR4n0
>
> Seems to have gotten messed up somehow. I can't see the package c-state
> info there at all for some reason. Also core c-states go only up to c7s.
> On hsw I would have expected to see deeper c-states, but maybe it's not
> a ult machine or something. My hsw-ult goes up to c10.

This part (i7-4750HQ) is not ULT.
I don't see any more information in the powertop ncurses UI that is in
the reports on pastebin. To be clear, you're not looking for this?

   Package     0
   Powered On 0.0%
   C1E-HSW    0.1%
   C3-HSW     0.0%
   RC6pp      0.0%
   C7s-HSW    93.9%

   GPU 0
   Powered On 0.3%
   RC6        99.7%
   RC6p       0.0%
   RC6pp      0.0%

>> Anything an outsider can do to help getting FBC enabled by default again?
>
> Either someone needs to review my patches or fix the fbc code in
> some other way. Even if someone wants to do the frontbuffer tracking
> some other way, there was plenty of stuff in my patches that can
> still be applied (there were even simple bugfixes included iirc).

Do you have a link to them, or a branch somewhere?

I also tried enable_psr=1 (on Linus' HEAD), but it has no significant
effect on power consumption on this machine.

Thanks,
Eric