Re: [PATCH] ALSA: hda - make power_save threshold per-codec

From: Matthew Garrett
Date: Thu Apr 09 2015 - 02:25:09 EST


On Wed, Apr 8, 2015 at 10:20 PM, Takashi Iwai <tiwai@xxxxxxx> wrote:
>
> At Wed, 8 Apr 2015 18:53:48 -0700,
> Matthew Garrett wrote:
> >
> > Modern hardware will often have multiple HDA devices, and the desired
> > power saving configuration may vary depending on the codecs attached to
> > each of them. Push the power_save value down to the individual codec
> > structures, keeping the module parameter as a global control mechanism
> > for compatibility purposes.
>
> This patch doesn't apply any longer at all to the recent code, since
> the power saving stuff has been already translated to the standard
> runtime PM. Take a look at linux-next tree.

Ah! Wonderful!

> Also we can't break the current behavior controlling the power save
> via option. Many programs rely on this mechanism, thus changing this
> would break its behavior.

Yeah, I kept that behaviour - anything that touches
/sys/module/snd_hda_intel/parameters/power_save just changes the
settings for all codecs.

> In the latest code, the common control via power_save module option is
> still there for compatibility, but you can also adjust the value for
> each codec in runtime attribute of each codec sysfs in addition.

That's ideal - I'll pull down next and rewrite my udev rules. Thanks!
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