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

[Liam Girdwood]

On Tue, 2015-06-16 at 10:34 +0200, Daniel Vetter wrote:
> Can I get an ack on this please? The audio folks already move ahead
> 
> http://permalink.gmane.org/gmane.linux.alsa.devel/139831
> 
> Would be embarassing if we are late to the party we organized ourselves ...
> -Daniel
> 
> 

Mengdong, Libin - I assume someone has tested this ? could someone Ack.

Thanks

Liam

> On Fri, May 8, 2015 at 8:51 PM, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> > Like with every other feature that's not enabled by default we break
> > runtime pm support way too often by accident because the overall test
> > coverage isn't great. And it's been almost 2 years since we enabled
> > the power well code by default
> >
> > commit bf51d5e2cda5d36d98e4b46ac7fca9461e512c41
> > Author: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > Date:   Wed Jul 3 17:12:13 2013 -0300
> >
> >     drm/i915: switch disable_power_well default value to 1
> >
> > It's really more than overdue for runtime pm itself to follow!
> >
> > Note that in practice this wont do a hole lot yet, since we're still
> > gated on snd-hda-intel doing proper runtime pm. But I've discussed
> > this with Liam and we agreed that this needs to be done. And the audio
> > team is working to hold up their end of this bargain.
> >
> > And the justification for updating the autosuspend delay to 100ms:
> > Quick measurment shows that we can do a full rpm cycle in about 5ms,
> > which means the delay should still be really conservative from a power
> > conservation pov. The only workload that would suffer from ping-pong
> > is also only gpu/compute with all screens off. 100ms should cover any
> > kind of latency with submitting follow-up batches.
> >
> > 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>
> > ---
> >  drivers/gpu/drm/i915/intel_runtime_pm.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > index 317b9b43d1c1..36ecbe275dd9 100644
> > --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > @@ -1919,9 +1919,10 @@ void intel_runtime_pm_enable(struct drm_i915_private *dev_priv)
> >                 return;
> >         }
> >
> > -       pm_runtime_set_autosuspend_delay(device, 10000); /* 10s */
> > +       pm_runtime_set_autosuspend_delay(device, 100);
> >         pm_runtime_mark_last_busy(device);
> >         pm_runtime_use_autosuspend(device);
> > +       pm_runtime_allow(device);
> >
> >         pm_runtime_put_autosuspend(device);
> >  }
> > --
> > 2.1.0
> >
> 
> 
> 


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