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

[Yang, Libin]

Hi Liam,

> -----Original Message-----
> From: Girdwood, Liam R
> Sent: Tuesday, June 16, 2015 6:42 PM
> To: Daniel Vetter; Lin, Mengdong; Yang, Libin
> Cc: Intel Graphics Development; Takashi Iwai; Yang, Libin; Lin,
> Mengdong; Li, Jocelyn; Kaskinen, Tanu; Zanoni, Paulo R; Vetter, Daniel
> Subject: Re: [PATCH] drm/i915: Enable runtime pm
> 
> 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.

Our patches are ready for this feature. Suppose Keqiao has test this feature.

> 
> 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
> > >
> >
> >
> >
>