On Wed, 24 Mar 2021 18:14:08 +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.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Just to be sure: this workaround is always needed no matter whether
reset_resume is set or not? If so, it's better to change the resume
callback to take reset_resume argument and call it always. The
resume_connector() can be folded into there.
thanks,
Takashi
> ---
> sound/usb/mixer.c | 18 ++++++++++++++++++
> sound/usb/mixer.h | 1 +
> 2 files changed, 19 insertions(+)
>
> diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
> index 98f5417a70e4..6a553d891b0f 100644
> --- a/sound/usb/mixer.c
> +++ b/sound/usb/mixer.c
> @@ -3631,11 +3631,28 @@ static int restore_mixer_value(struct usb_mixer_elem_list *list)
> return 0;
> }
>
> +static int resume_connector(struct usb_mixer_elem_list *list)
> +{
> + struct usb_mixer_elem_info *cval = mixer_elem_list_to_info(list);
> +
> + if (cval->val_type != USB_MIXER_BOOLEAN || cval->channels != 1)
> + return 0;
> +
> + return get_connector_value(cval, NULL, NULL);
> +}
> +
> int snd_usb_mixer_resume(struct usb_mixer_interface *mixer, bool reset_resume)
> {
> struct usb_mixer_elem_list *list;
> int id, err;
>
> + for (id = 0; id < MAX_ID_ELEMS; id++) {
> + for_each_mixer_elem(list, mixer, id) {
> + if (list->resume_connector)
> + list->resume_connector(list);
> + }
> + }
> +
> if (reset_resume) {
> /* restore cached mixer values */
> for (id = 0; id < MAX_ID_ELEMS; id++) {
> @@ -3664,5 +3681,6 @@ void snd_usb_mixer_elem_init_std(struct usb_mixer_elem_list *list,
> list->dump = snd_usb_mixer_dump_cval;
> #ifdef CONFIG_PM
> list->resume = restore_mixer_value;
> + list->resume_connector = resume_connector;
> #endif
> }
> diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
> index c29e27ac43a7..843ccff0eea3 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 resume_connector;
> };
>
> /* iterate over mixer element list of the given unit id */
> --
> 2.30.2
>
