Re: [PATCH] ASoC: rt722-sdca: add FU06 Playback Switch for speaker mute control

Aaron Ma
2026-04-24T03:53:02Z

On Thu, Apr 23, 2026 at 9:01 PM Pierre-Louis Bossart
<pierre-louis.bossart@linux.dev> wrote:
>
> On 4/23/26 12:13, Aaron Ma wrote:
> > The rt722-sdca codec driver exposes FU06 Playback Volume but no
> > corresponding mute switch. Without a user-facing ALSA switch, UCM
> > cannot attach the speaker mute LED via snd_ctl_led, and PipeWire
> > cannot drive hardware mute.
> >
> > Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
> > ---
> > sound/soc/codecs/rt722-sdca.c | 77 ++++++++++++++++++++++++++++-------
> > sound/soc/codecs/rt722-sdca.h | 4 ++
> > 2 files changed, 67 insertions(+), 14 deletions(-)
> >
> > diff --git a/sound/soc/codecs/rt722-sdca.c b/sound/soc/codecs/rt722-sdca.c
> > index 79b8b7e70a334..23d2f63d68ef3 100644
> > --- a/sound/soc/codecs/rt722-sdca.c
> > +++ b/sound/soc/codecs/rt722-sdca.c
> > @@ -517,6 +517,61 @@ static int rt722_sdca_fu1e_capture_put(struct snd_kcontrol *kcontrol,
> > return changed;
> > }
> >
> > +static int rt722_sdca_set_fu06_playback_ctl(struct rt722_sdca_priv *rt722)
> > +{
> > + int err;
> > + unsigned int ch_l, ch_r;
> > +
> > + ch_l = (rt722->fu06_dapm_mute || rt722->fu06_mixer_l_mute) ? 0x01 : 0x00;
> > + ch_r = (rt722->fu06_dapm_mute || rt722->fu06_mixer_r_mute) ? 0x01 : 0x00;
> > +
> > + err = regmap_write(rt722->regmap,
> > + SDW_SDCA_CTL(FUNC_NUM_AMP, RT722_SDCA_ENT_USER_FU06,
> > + RT722_SDCA_CTL_FU_MUTE, CH_L), ch_l);
> > + if (err < 0)
> > + return err;
> > +
> > + err = regmap_write(rt722->regmap,
> > + SDW_SDCA_CTL(FUNC_NUM_AMP, RT722_SDCA_ENT_USER_FU06,
> > + RT722_SDCA_CTL_FU_MUTE, CH_R), ch_r);
>
> IIRC you can mute all channels at once in a FU (Feature Unit) using Control Number 0.
>
> If both channels need to be muted/unmuted it's better to do so in a single command.
>

Thanks for the review.

The per-channel mute writes are unchanged from the existing DAPM
handler, just moved into a helper.
All rt711/rt712/rt722 drivers use per-channel writes for FU_MUTE — no
CN0 precedent exists.

Aaron