[alsa-devel] Multiple speaker jacks (on an IDT codec)

[Takashi Iwai]

At Thu, 06 Sep 2012 00:59:15 +0200,
David Henningsson wrote:
> 
> Hi,
> 
> I'm having a problem with a machine where the parser creates indexed 
> speaker controls. For reference, codecs/idt92hd206-ecs-gf7100pvt shows 
> the same problem.
> 
> I could use some input on how to fix it in the best way.
> 
> My first thought was that "[Jack] Speaker" is stupid in itself, and 
> could be fixed like this:
> 
> diff --git a/sound/pci/hda/hda_auto_parser.c 
> b/sound/pci/hda/hda_auto_parser.c
> index 4f7d2df..8e32ee5 100644
> --- a/sound/pci/hda/hda_auto_parser.c
> +++ b/sound/pci/hda/hda_auto_parser.c
> @@ -171,6 +171,10 @@ int snd_hda_parse_pin_defcfg(struct hda_codec *codec,
>                          if (conn == AC_JACK_PORT_FIXED)
>                                  dev = AC_JACK_SPEAKER;
>                  }
> +               else if (dev == AC_JACK_SPEAKER) {
> +                       if (conn == AC_JACK_PORT_COMPLEX)
> +                               dev = AC_JACK_LINE_OUT;
> +               }
> 
>                  switch (dev) {
>                  case AC_JACK_LINE_OUT:
> 
> ...but changing generic code is always a bit scary and regression prone 
> (even though I could not think of a good counterexample where that would 
> happen), so not sure if that's the best idea.

Right.  I remember that there are more devices declaring the speakers
in that way.

> Next attempt is to modify the control creating function for IDT:
> 
> diff --git a/sound/pci/hda/patch_sigmatel.c b/sound/pci/hda/patch_sigmatel.c
> index 9db3056..c16d0f8 100644
> --- a/sound/pci/hda/patch_sigmatel.c
> +++ b/sound/pci/hda/patch_sigmatel.c
> @@ -3226,9 +3226,12 @@ static int create_multi_out_ctls(struct hda_codec 
> *codec, int num_outs,
>                                  idx = i;
>                                  break;
>                          case AUTO_PIN_SPEAKER_OUT:
> -                               name = "Speaker";
> -                               idx = i;
> -                               break;
> +                               if (num_outs <= 1) {
> +                                       name = "Speaker";
> +                                       idx = i;
> +                                       break;
> +                               }
> +                               /* Fall through in case of multi speaker 
> outs */
>                          default:
>                                  name = chname[i];
>                                  idx = 0;
> 
> 
> ...since the current behaviour is inconsistent anyway - you get indices 
> for 1 and 3, but "Center"/"LFE" for what should otherwise have been index 2.

Yeah, certainly something fishy there.
IIRC, the exception was introduced to handle the bass speaker.
But I guess it's already broken in some level, so we need to revisit
the implementation.

A concern for the change like above is whether it handles correctly
the case where machines has multiple built-in speakers with a single
headphone jack.  We need to check this.

> Another way would to just write a pin fix to turn these speakers into 
> line outs, which is what they really are anyway.
> 
> What do you think?

This might be a safer option.


Takashi