Subject: Re: [PATCH 3/3] ASoC: fsl-asoc-card: Support Headphone and Microphone Jack detection

From: Nicolin Chen <[email-masked]>
Date: Tue, 14 Jul 2020 23:40:58 -0700

On Wed, Jul 15, 2020 at 12:14:01PM +0800, Shengjiu Wang wrote:
> On Wed, Jul 15, 2020 at 5:16 AM Nicolin Chen <[email-masked]> wrote:
> >
> > Hi Shengjiu,
> >
> > The whole series looks good to me. Just a couple of small
> > questions inline:
> >
> > On Tue, Jul 14, 2020 at 05:05:36PM +0800, Shengjiu Wang wrote:
> > > Use asoc_simple_init_jack function from simple card to implement
> > > the Headphone and Microphone detection.
> > > Register notifier to disable Speaker when Headphone is plugged in
> > > and enable Speaker when Headphone is unplugged.
> > > Register notifier to disable Digital Microphone when Analog Microphone
> > > is plugged in and enable DMIC when Analog Microphone is unplugged.
> > >
> > > Signed-off-by: Shengjiu Wang <[email-masked]>
> > > ---
> > >  sound/soc/fsl/Kconfig         |  1 +
> > >  sound/soc/fsl/fsl-asoc-card.c | 69 ++++++++++++++++++++++++++++++++++-
> > >  2 files changed, 68 insertions(+), 2 deletions(-)
> >
> > >  static int fsl_asoc_card_late_probe(struct snd_soc_card *card)
> > >  {
> > >       struct fsl_asoc_card_priv *priv = snd_soc_card_get_drvdata(card);
> > > @@ -745,8 +789,29 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
> > >       snd_soc_card_set_drvdata(&priv->card, priv);
> > >
> > >       ret = devm_snd_soc_register_card(&pdev->dev, &priv->card);
> > > -     if (ret && ret != -EPROBE_DEFER)
> > > -             dev_err(&pdev->dev, "snd_soc_register_card failed (%d)\n", ret);
> > > +     if (ret) {
> > > +             if (ret != -EPROBE_DEFER)
> > > +                     dev_err(&pdev->dev, "snd_soc_register_card failed (%d)\n", ret);
> >
> > I think we may move this EPROBE_DEFER to the asrc_fail label.
> 
> If we move this to asrc_fail label, then it will be hard to define the
> error message.
> There are many places that goto asrc_fail.

Oh...good point...

> > > +             goto asrc_fail;
> > > +     }
> > > +
> > > +     if (of_property_read_bool(np, "hp-det-gpio")) {
> >
> > Could we move this check inside asoc_simple_init_jack? There's no
> > problem with doing it here though, yet I got a bit confused by it
> > as I thought it's a boolean type property, which would be against
> > the DT bindings until I saw asoc_simple_init_jack() uses the same
> > string to get the GPIO. Just it probably would be a bit tricky as
> > we need it to be optional here.
> >
> > Otherwise, I think we may add a line of comments to indicate that
> > the API would use the same string to get the GPIO.
> 
> In asoc_simple_init_jack, gpio_is_valid() will be invalid when there is
> no "hp-det-gpio" property, and asoc_simple_init_jack will return 0.
> 
> The reason why I add a check here is mostly for
> snd_soc_jack_notifier_register().
> when there is no jack created, there will be a kernel dump.
> 
> or I can use this code:
> 
> -       if (of_property_read_bool(np, "hp-det-gpio")) {
> -               ret = asoc_simple_init_jack(&priv->card, &priv->hp_jack,
> -                                           1, NULL, "Headphone Jack");
> -               if (ret)
> -                       goto asrc_fail;
> +       ret = asoc_simple_init_jack(&priv->card, &priv->hp_jack,
> +                                   1, NULL, "Headphone Jack");
> +       if (ret)
> +               goto asrc_fail;
> 
> +       if (priv->hp_jack.jack.jack)
>                 snd_soc_jack_notifier_register(&priv->hp_jack.jack,

It's pretty clean but not very obvious for the "optional" part.
So I think that it'd be slightly better to go for your previous
solution, but with a line of comments to show: these properties
are optional and asoc_simple_init_jack() uses the same strings.

Please add to all three changes once the comments being added:

Acked-by: Nicolin Chen <[email-masked]>

Thanks