[alsa-devel] [PATCH] ALSA: hda - modem function group wake on ring support

[Takashi Iwai]

At Thu, 7 Jun 2012 18:09:28 +0800,
Wang Xingchao wrote:
> 
> 2012/6/7 Takashi Iwai <tiwai at suse.de>:
> > At Thu,  7 Jun 2012 16:52:33 +0800,
> > Wang Xingchao wrote:
> >>
> >>  D2 allows for the lowest possible power consuming
> >>  state from which it can return to "fully on" state D0 within 2ms.
> >>  For modems, it's the "wake on ring" power state.
> >>
> >> Signed-off-by: Wang Xingchao <xingchao.wang at intel.com>
> >> ---
> >>  sound/pci/hda/hda_codec.c |   12 ++++++++++++
> >>  1 file changed, 12 insertions(+)
> >>
> >> diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
> >> index 2737fe7..d0ca370 100644
> >> --- a/sound/pci/hda/hda_codec.c
> >> +++ b/sound/pci/hda/hda_codec.c
> >> @@ -3542,6 +3542,18 @@ static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg,
> >>       snd_hda_codec_set_power_to_all(codec, fg, power_state, true);
> >>  }
> >>
> >> +/* modem wake on ring: transition from D2 to D0 in less than 2ms. For modems,
> >> + * this is the wake-on-ring power state  */
> >> +static void hda_modem_wake_on_ring(struct hda_codec *codec, bool enter)
> >> +{
> >> +     if (codec->mfg) {
> >> +             if (enter)
> >> +                     hda_set_power_state(codec, codec->mfg, AC_PWRST_D2);
> >> +             else
> >> +                     hda_set_power_state(codec, codec->mfg, AC_PWRST_D0);
> >> +     }
> >> +}
> >> +
> >>  #ifdef CONFIG_SND_HDA_HWDEP
> >>  /* execute additional init verbs */
> >>  static void hda_exec_init_verbs(struct hda_codec *codec)
> >
> > No caller of the new function?  Otherwise it's useless...
> >
> Hi Takashi,
> 
> I have not see codec indicates "Modem function group" yet, do you know
> which codec on HDA as Modem type and i could search whether it need
> such "wake on ring" feature.
> 
> This patch should bring codec out of D2 states in less than 2ms. It
> should help modem save power with "wake-on-ring" feature.

But you added only a function definition that is called from nowhere?


Takashi

> 
> thanks
> --xingchao
>