Re: [PATCH 4/4] ALSA: hda/senary: Fix microphone boost stability

[Takashi Iwai]

On Thu, 05 Mar 2026 04:27:56 +0100,
wangdich9700@xxxxxxx wrote:
> 
> From: wangdicheng <wangdicheng@xxxxxxxxxx>
> 
> Some SN6186 platforms experience microphone gain fluctuation.

What does this mean actually...?

> This patch adds a capture sync hook to lock the microphone boost
> to a default value read during initialization, ensuring stable
> recording levels.

But it means that the mic boost value changed by users (via mixer)
won't be followed at all?  Sounds fishy.


thanks,

Takashi

> 
> Signed-off-by: wangdicheng <wangdicheng@xxxxxxxxxx>
> ---
>  sound/hda/codecs/senarytech.c | 33 +++++++++++++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/sound/hda/codecs/senarytech.c b/sound/hda/codecs/senarytech.c
> index c589b3b01171..9c6bad6e3866 100644
> --- a/sound/hda/codecs/senarytech.c
> +++ b/sound/hda/codecs/senarytech.c
> @@ -31,6 +31,7 @@ struct senary_spec {
>  	unsigned int parse_flags; /* flag for snd_hda_parse_pin_defcfg() */
>  
>  	int mute_led_polarity;
> +	unsigned char default_mic_boost[0x25];
>  	unsigned int gpio_led;
>  	unsigned int gpio_mute_led_mask;
>  	unsigned int gpio_mic_led_mask;
> @@ -162,6 +163,30 @@ static void senary_playback_hook(struct hda_pcm_stream *hinfo,
>  	}
>  }
>  
> +static void senary_fixed_mic_boost(struct hda_codec *codec, hda_nid_t nid)
> +{
> +	unsigned char value;
> +	struct senary_spec *spec = codec->spec;
> +
> +	if (!spec->default_mic_boost[nid])
> +		return;
> +
> +	value = snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_AMP_GAIN_MUTE, 0);
> +	if (value != spec->default_mic_boost[nid])
> +		snd_hda_codec_amp_stereo(codec, nid, HDA_INPUT, 0,
> +				HDA_AMP_VOLMASK, spec->default_mic_boost[nid]);
> +}
> +
> +static void senary_cap_sync_hook(struct hda_codec *codec,
> +		struct snd_kcontrol *kcontrol,
> +		struct snd_ctl_elem_value *ucontrol)
> +{
> +	struct senary_spec *spec = codec->spec;
> +	hda_nid_t nid = spec->gen.imux_pins[spec->gen.cur_mux[0]];
> +
> +	senary_fixed_mic_boost(codec, nid);
> +}
> +
>  static void senary_auto_turn_eapd(struct hda_codec *codec, int num_pins,
>  			      const hda_nid_t *pins, bool on)
>  {
> @@ -251,6 +276,7 @@ static int senary_probe(struct hda_codec *codec, const struct hda_device_id *id)
>  {
>  	struct senary_spec *spec;
>  	int err;
> +	int i;
>  
>  	codec_info(codec, "%s: BIOS auto-probing.\n", codec->core.chip_name);
>  
> @@ -307,6 +333,13 @@ static int senary_probe(struct hda_codec *codec, const struct hda_device_id *id)
>  	if (codec->core.vendor_id == 0x1fa86186)
>  		spec->gen.pcm_playback_hook = senary_playback_hook;
>  
> +	/* Initialize and fix mic boost */
> +	for (i = 0; i < ARRAY_SIZE(spec->default_mic_boost); i++) {
> +		spec->default_mic_boost[i] = snd_hda_codec_read(codec, i, 0,
> +				AC_VERB_GET_AMP_GAIN_MUTE, 0);
> +	}
> +	spec->gen.cap_sync_hook = senary_cap_sync_hook;
> +
>  	/* Some laptops with Senary chips show stalls in S3 resume,
>  	 * which falls into the single-cmd mode.
>  	 * Better to make reset, then.
> -- 
> 2.25.1
>