[alsa-devel] [PATCH v2] ASoC: Add pinctrl PM to components of active DAIs

[Nicolin Chen]

On Tue, Oct 29, 2013 at 11:25:12AM +0800, Nicolin Chen wrote:
> Hi Kyungmin,
> 
> On Tue, Oct 29, 2013 at 12:35:06PM +0900, Kyungmin Park wrote:
> > > +       /* deactivate pins to sleep state */
> > > +       for (i = 0; i < card->num_rtd; i++) {
> > > +               struct snd_soc_pcm_runtime *rtd = &card->rtd[i];
> > > +               struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
> > > +               pinctrl_pm_select_sleep_state(cpu_dai->dev);
> > 
> > I wonder doesn't check it's active or not? if codec is used during
> > suspend. it doesn't set sleep state?
> 
> I thought codec wouldn't do anything meaningful to cpu dai since the
> whole system is going to suspend. But it should be better to add the
> condition here as well. I'll send a v3.

Wait...For those inactive streams, they're already in sleep state so it
doesn't matter to call pinctrl_pm_select_sleep_state() or not; While for
those active streams, if we undo this pinctrl_pm_select_sleep_state(),
their pins're remaining active during suspend without any power-saving.

So I think maybe I was right at the first place that it's okay not to set
a condition here? Since the card is going to suspend, why do we need to
care codec's behavior? Please correct me if I'm wrong.

Thank you,
Nicolin Chen