[Intel-gfx] [PATCH] drm/i915: Enable runtime pm

[David Weinehall]

On Thu, Nov 16, 2017 at 08:24:02PM +0200, David Weinehall wrote:
> On Wed, Nov 08, 2017 at 04:25:42PM +0200, David Weinehall wrote:
> > On Tue, Nov 07, 2017 at 05:18:21PM +0100, Daniel Vetter wrote:
> > > Now that we have CI, and that pm_rpm fully passes (I guess the audio
> > > folks have implemented proper runtime pm for snd-hda, hooray, pls
> > > confirm) it's time to enable this again by default.
> > > 
> > > Real goal here is to have 1 configuration only that we fully support,
> > > instead of tons of different codes with every user/customer tuning it
> > > differently. And really, power stuff should work by default, and
> > > should be enabled by everywhere where it is save to do so.
> > > 
> > > v2: Completely new commit message, a few years passed since v1 ...
> > > 
> > > Cc: Takashi Iwai <tiwai at suse.de>
> > > Cc: Liam Girdwood <liam.r.girdwood at intel.com>
> > > Cc: "Yang, Libin" <libin.yang at intel.com>
> > > Cc: "Lin, Mengdong" <mengdong.lin at intel.com>
> > > Cc: "Li, Jocelyn" <jocelyn.li at intel.com>
> > > Cc: "Kaskinen, Tanu" <tanu.kaskinen at intel.com>
> > > Cc: "Zanoni, Paulo R" <paulo.r.zanoni at intel.com>
> > > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> > 
> > lgtm,
> > 
> > Reviewed-by: David Weinehall <david.weinehall at linux.intel.com>
> 
> Been testing a bit; test results are a bit discouraging when it comes to
> idle power consumption.
> 
> Our nightly test suite logs idle power consumption before running any
> tests, after running all tests, and then finally after running
> powertop --auto-tune.
> 
> The before and after cases are similar with and without patch,
> but not so for the auto-tune case.
> 
> Without this patch, powertop --auto-tune yields a massive improvement
> (on NUC6i5 the power consumption drops with more than a factor of 3),
> while with this patch the power consumption just drops with 10% or so.

With the 10s => 0.1s bit of the patch reverted there's no longer any
--auto-tune regression.


Kind regards, David