[alsa-devel] [PATCH] ALSA: hda - Enable runtime pm for Haswell

[Wang, Xingchao]

Hi,

Add Rafael in loop.

> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai at suse.de]
> Sent: Thursday, May 16, 2013 4:49 PM
> To: Wang Xingchao
> Cc: Girdwood, Liam R; Lin, Mengdong; Li, Jocelyn; alsa-devel at alsa-project.org;
> Wang, Xingchao
> Subject: Re: [PATCH] ALSA: hda - Enable runtime pm for Haswell
> 
> At Thu, 16 May 2013 16:29:05 +0800,
> Wang Xingchao wrote:
> >
> > Haswell doesnot support runtime pm by default.
> > This patch let haswell Display HD-A controller enter runtime suspend,
> > and bring more power saving whith power-well.
> >
> > Signed-off-by: Wang Xingchao <xingchao.wang at linux.intel.com>
> 
> I don't think it's good to fiddle such a thing in the driver side.
> If Haswell can support runtime PM really, it should be set commonly.

I wonder whether it's HD-A driver's policy to only support runtime PM if the device can support signal wakup?
According to Rafael, the device can support runtime PM regardless, no matter it supports PME or not.
If so, we should remove the "if" condition check here.

Thanks
--xingchao

> 
> 
> Takashi
> 
> > ---
> >  sound/pci/hda/hda_intel.c |    6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> > index bf27693..eb25888 100644
> > --- a/sound/pci/hda/hda_intel.c
> > +++ b/sound/pci/hda/hda_intel.c
> > @@ -3755,6 +3755,12 @@ static int azx_probe(struct pci_dev *pci,
> >
> >  	if (pci_dev_run_wake(pci))
> >  		pm_runtime_put_noidle(&pci->dev);
> > +	else if (chip->driver_caps
> > +			& AZX_DCAPS_I915_POWERWELL) {
> > +		/* Haswell doesnot support runtime pm by default */
> > +		pm_runtime_put_noidle(&pci->dev);
> > +		pm_runtime_allow(&pci->dev);
> > +	}
> >
> >  	dev++;
> >  	complete_all(&chip->probe_wait);
> > --
> > 1.7.9.5
> >