Jack detection is currently fully functional via the input
interface together with multimedia buttons, but is not exposed
as an ALSA control. Therefore, ALSA clients such as PulseAudio
do not pick up the jack detection events as they only support
one of the possible interface (ALSA control or input interface,
but not both). Expose the jack events as an ALSA control and input
interface to provide ALSA clients both interfaces.

Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>
---
 sound/soc/codecs/wcd-mbhc-v2.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sound/soc/codecs/wcd-mbhc-v2.c b/sound/soc/codecs/wcd-mbhc-v2.c
index 1911750f7445..1b75f49b2858 100644
--- a/sound/soc/codecs/wcd-mbhc-v2.c
+++ b/sound/soc/codecs/wcd-mbhc-v2.c
@@ -725,6 +725,10 @@ static int wcd_mbhc_initialise(struct wcd_mbhc *mbhc)
 
 	mutex_lock(&mbhc->lock);
 
+	ret = snd_jack_add_new_kctl(mbhc->jack->jack, "Headset Jack", WCD_MBHC_JACK_MASK);
+	if (ret)
+		dev_warn(component->dev, "failed creating Headset Jack kctl with err: %d\n", ret);
+
 	/* enable HS detection */
 	if (mbhc->mbhc_cb->hph_pull_up_control_v2)
 		mbhc->mbhc_cb->hph_pull_up_control_v2(component,
-- 
2.37.3

Tested on a OnePlus 6 running postmarketOS!

On 07/10/2022 16:57, Dylan Van Assche wrote:
> Jack detection is currently fully functional via the input
> interface together with multimedia buttons, but is not exposed
> as an ALSA control. Therefore, ALSA clients such as PulseAudio
> do not pick up the jack detection events as they only support
> one of the possible interface (ALSA control or input interface,
> but not both). Expose the jack events as an ALSA control and input
> interface to provide ALSA clients both interfaces.
>
> Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>

Tested-by: Caleb Connolly <caleb@connolly.tech>

> ---
>   sound/soc/codecs/wcd-mbhc-v2.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/sound/soc/codecs/wcd-mbhc-v2.c b/sound/soc/codecs/wcd-mbhc-v2.c
> index 1911750f7445..1b75f49b2858 100644
> --- a/sound/soc/codecs/wcd-mbhc-v2.c
> +++ b/sound/soc/codecs/wcd-mbhc-v2.c
> @@ -725,6 +725,10 @@ static int wcd_mbhc_initialise(struct wcd_mbhc *mbhc)
>
>   	mutex_lock(&mbhc->lock);
>
> +	ret = snd_jack_add_new_kctl(mbhc->jack->jack, "Headset Jack", WCD_MBHC_JACK_MASK);
> +	if (ret)
> +		dev_warn(component->dev, "failed creating Headset Jack kctl with err: %d\n", ret);
> +
>   	/* enable HS detection */
>   	if (mbhc->mbhc_cb->hph_pull_up_control_v2)
>   		mbhc->mbhc_cb->hph_pull_up_control_v2(component,
> --
> 2.37.3
>

--
Kind Regards,
Caleb

Can confirm that this is required for Pulseaudio to pick up the
headphones properly. I tested this in my Xiaomi Poco F1 running
postmarketOS (Phosh Mobile Desktop Environment). You can check the
following pulseaudio issue for some more info.

Link: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/issues/1377

Tested-by: Joel Selvaraj <joelselvaraj.oss@gmail.com>

On 07/10/22 10:57, Dylan Van Assche wrote:
> Jack detection is currently fully functional via the input
> interface together with multimedia buttons, but is not exposed
> as an ALSA control. Therefore, ALSA clients such as PulseAudio
> do not pick up the jack detection events as they only support
> one of the possible interface (ALSA control or input interface,
> but not both). Expose the jack events as an ALSA control and input
> interface to provide ALSA clients both interfaces.
> 
> Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>
> ---
>  sound/soc/codecs/wcd-mbhc-v2.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/sound/soc/codecs/wcd-mbhc-v2.c b/sound/soc/codecs/wcd-mbhc-v2.c
> index 1911750f7445..1b75f49b2858 100644
> --- a/sound/soc/codecs/wcd-mbhc-v2.c
> +++ b/sound/soc/codecs/wcd-mbhc-v2.c
> @@ -725,6 +725,10 @@ static int wcd_mbhc_initialise(struct wcd_mbhc *mbhc)
>  
>  	mutex_lock(&mbhc->lock);
>  
> +	ret = snd_jack_add_new_kctl(mbhc->jack->jack, "Headset Jack", WCD_MBHC_JACK_MASK);
> +	if (ret)
> +		dev_warn(component->dev, "failed creating Headset Jack kctl with err: %d\n", ret);
> +
>  	/* enable HS detection */
>  	if (mbhc->mbhc_cb->hph_pull_up_control_v2)
>  		mbhc->mbhc_cb->hph_pull_up_control_v2(component,