* power management in alsa
@ 2007-07-25 12:36 Andi Kleen
2007-07-25 12:58 ` Takashi Iwai
0 siblings, 1 reply; 4+ messages in thread
From: Andi Kleen @ 2007-07-25 12:36 UTC (permalink / raw)
To: tiwai, perex, linux-pm
Hallo,
I noticed ALSA hda seems to only change PCI power management states
of the sound devices on suspend/resume. Is there a reason the device
cannot be automatically suspended when nobody has sound opened?
-Andi
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: power management in alsa
2007-07-25 12:36 power management in alsa Andi Kleen
@ 2007-07-25 12:58 ` Takashi Iwai
2007-07-25 18:41 ` Pavel Machek
0 siblings, 1 reply; 4+ messages in thread
From: Takashi Iwai @ 2007-07-25 12:58 UTC (permalink / raw)
To: Andi Kleen; +Cc: linux-pm, perex
At Wed, 25 Jul 2007 14:36:58 +0200,
Andi Kleen wrote:
>
>
> Hallo,
>
> I noticed ALSA hda seems to only change PCI power management states
> of the sound devices on suspend/resume. Is there a reason the device
> cannot be automatically suspended when nobody has sound opened?
I made once the automatic power-control patch for hd-audio, but it was
possibly racy and a bit messy implementation, so I abandoned it.
Since then, no one has worked on this issue.
Takashi
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Re: power management in alsa
2007-07-25 12:58 ` Takashi Iwai
@ 2007-07-25 18:41 ` Pavel Machek
2007-07-26 10:04 ` Takashi Iwai
0 siblings, 1 reply; 4+ messages in thread
From: Pavel Machek @ 2007-07-25 18:41 UTC (permalink / raw)
To: Takashi Iwai; +Cc: linux-pm, Andi Kleen, perex
Hi!
> > I noticed ALSA hda seems to only change PCI power management states
> > of the sound devices on suspend/resume. Is there a reason the device
> > cannot be automatically suspended when nobody has sound opened?
>
> I made once the automatic power-control patch for hd-audio, but it was
> possibly racy and a bit messy implementation, so I abandoned it.
> Since then, no one has worked on this issue.
IIRC that patch saved .3W, which is quite significant -- about half of
spinning harddrive. I'd say it is worth the effort.
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Re: power management in alsa
2007-07-25 18:41 ` Pavel Machek
@ 2007-07-26 10:04 ` Takashi Iwai
0 siblings, 0 replies; 4+ messages in thread
From: Takashi Iwai @ 2007-07-26 10:04 UTC (permalink / raw)
To: Pavel Machek; +Cc: linux-pm, Andi Kleen, perex
At Wed, 25 Jul 2007 18:41:50 +0000,
Pavel Machek wrote:
>
> Hi!
>
> > > I noticed ALSA hda seems to only change PCI power management states
> > > of the sound devices on suspend/resume. Is there a reason the device
> > > cannot be automatically suspended when nobody has sound opened?
> >
> > I made once the automatic power-control patch for hd-audio, but it was
> > possibly racy and a bit messy implementation, so I abandoned it.
> > Since then, no one has worked on this issue.
>
> IIRC that patch saved .3W, which is quite significant -- about half of
> spinning harddrive. I'd say it is worth the effort.
OK, then I'll take a look again (and try reimplementing a bit better :)
thanks,
Takashi
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2007-07-26 10:04 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2007-07-25 12:36 power management in alsa Andi Kleen
2007-07-25 12:58 ` Takashi Iwai
2007-07-25 18:41 ` Pavel Machek
2007-07-26 10:04 ` Takashi Iwai
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