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References: <20210325121250.133009-1-kai.heng.feng@canonical.com>
 <20210325121250.133009-2-kai.heng.feng@canonical.com> <s5hczvnmju0.wl-tiwai@suse.de>
In-Reply-To: <s5hczvnmju0.wl-tiwai@suse.de>
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
Date:   Thu, 25 Mar 2021 21:55:06 +0800
Message-ID: <CAAd53p79HSpNKu69ZM7vRGWQT+9ydf59hGH-yNMT=Ymbg2NebA@mail.gmail.com>
Subject: Re: [PATCH v2 2/2] ALSA: usb-audio: Check connector value on resume
To:     Takashi Iwai <tiwai@suse.de>
Cc:     Takashi Iwai <tiwai@suse.com>, Jaroslav Kysela <perex@perex.cz>,
        Pavel Skripkin <paskripkin@gmail.com>,
        Chris Chiu <chiu@endlessm.com>,
        Mark Brown <broonie@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Tom Yan <tom.ty89@gmail.com>, Joe Perches <joe@perches.com>,
        "moderated list:SOUND" <alsa-devel@alsa-project.org>,
        open list <linux-kernel@vger.kernel.org>
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On Thu, Mar 25, 2021 at 9:41 PM Takashi Iwai <tiwai@suse.de> wrote:
>
> On Thu, 25 Mar 2021 13:12:48 +0100,
> Kai-Heng Feng wrote:
> >
> > Rear Mic on Lenovo P620 cannot record after S3, despite that there's no
> > error and the other two functions of the USB audio, Line In and Line
> > Out, work just fine.
> >
> > The mic starts to work again after running userspace app like "alsactl
> > store". Following the lead, the evidence shows that as soon as connector
> > status is queried, the mic can work again.
> >
> > So also check connector value on resume to "wake up" the USB audio to
> > make it functional.
> >
> > This can be device specific, however I think this generic approach may
> > benefit more than one device.
> >
> > While at it, also remove reset-resume path to consolidate mixer resume
> > path.
> >
> > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > ---
> > v2:
> >  - Remove reset-resume.
> >  - Fold the connector checking to the mixer resume callback.
>
> That's not what I meant exactly...  I meant to put both into the
> single resume callback, but handle each part conditionally depending
> on reset_resume argument.

OK, I get what you mean now.

>
> But this turned out to need more changes in mixer_quirks.c
> unnecessarily.  Maybe adding the two resume functions is a better
> approach in the end, but not for the specific connection thing but
> generically both resume and reset_resume callbacks.  Something like
> below.

This approach looks good. Let me send another one.

Kai-Heng

>
>
> thanks,
>
> Takashi
>
>
> diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
> index b004b2e63a5d..1dab281bb269 100644
> --- a/sound/usb/mixer.c
> +++ b/sound/usb/mixer.c
> @@ -3615,20 +3615,43 @@ static int restore_mixer_value(struct usb_mixer_elem_list *list)
>         return 0;
>  }
>
> +static int default_mixer_resume(struct usb_mixer_elem_list *list)
> +{
> +       struct usb_mixer_elem_info *cval = mixer_elem_list_to_info(list);
> +
> +       /* get connector value to "wake up" the USB audio */
> +       if (cval->val_type == USB_MIXER_BOOLEAN && cval->channels == 1)
> +               get_connector_value(cval, NULL, NULL);
> +
> +       return 0;
> +}
> +
> +static int default_mixer_reset_resume(struct usb_mixer_elem_list *list)
> +{
> +       int err = default_mixer_resume(list);
> +
> +       if (err < 0)
> +               return err;
> +       return restore_mixer_value(list);
> +}
> +
>  int snd_usb_mixer_resume(struct usb_mixer_interface *mixer, bool reset_resume)
>  {
>         struct usb_mixer_elem_list *list;
> +       usb_mixer_elem_resume_func_t f;
>         int id, err;
>
> -       if (reset_resume) {
> -               /* restore cached mixer values */
> -               for (id = 0; id < MAX_ID_ELEMS; id++) {
> -                       for_each_mixer_elem(list, mixer, id) {
> -                               if (list->resume) {
> -                                       err = list->resume(list);
> -                                       if (err < 0)
> -                                               return err;
> -                               }
> +       /* restore cached mixer values */
> +       for (id = 0; id < MAX_ID_ELEMS; id++) {
> +               for_each_mixer_elem(list, mixer, id) {
> +                       if (reset_resume)
> +                               f = list->reset_resume;
> +                       else
> +                               f = list->resume;
> +                       if (f) {
> +                               err = list->resume(list);
> +                               if (err < 0)
> +                                       return err;
>                         }
>                 }
>         }
> @@ -3647,6 +3670,7 @@ void snd_usb_mixer_elem_init_std(struct usb_mixer_elem_list *list,
>         list->id = unitid;
>         list->dump = snd_usb_mixer_dump_cval;
>  #ifdef CONFIG_PM
> -       list->resume = restore_mixer_value;
> +       list->resume = default_mixer_resume;
> +       list->reset_resume = default_mixer_reset_resume;
>  #endif
>  }
> diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
> index c29e27ac43a7..e5a01f17bf3c 100644
> --- a/sound/usb/mixer.h
> +++ b/sound/usb/mixer.h
> @@ -69,6 +69,7 @@ struct usb_mixer_elem_list {
>         bool is_std_info;
>         usb_mixer_elem_dump_func_t dump;
>         usb_mixer_elem_resume_func_t resume;
> +       usb_mixer_elem_resume_func_t reset_resume;
>  };
>
>  /* iterate over mixer element list of the given unit id */
> diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c
> index ffd922327ae4..b7f9c2fded05 100644
> --- a/sound/usb/mixer_quirks.c
> +++ b/sound/usb/mixer_quirks.c
> @@ -151,7 +151,7 @@ static int add_single_ctl_with_resume(struct usb_mixer_interface *mixer,
>                 *listp = list;
>         list->mixer = mixer;
>         list->id = id;
> -       list->resume = resume;
> +       list->reset_resume = resume;
>         kctl = snd_ctl_new1(knew, list);
>         if (!kctl) {
>                 kfree(list);