Re: [PATCH 3/4] ALSA: hda/senary: Add dynamic EAPD control via playback hook

[Takashi Iwai]

On Thu, 05 Mar 2026 04:27:41 +0100,
wangdich9700@xxxxxxx wrote:
> 
> From: wangdicheng <wangdicheng@xxxxxxxxxx>
> 
> To reduce power consumption and eliminate static noise during idle,
> this patch introduces dynamic EAPD switching. It hooks into the PCM
> playback stream to turn EAPD on only when audio is playing and off
> when the stream stops.
> 
> Signed-off-by: wangdicheng <wangdicheng@xxxxxxxxxx>

Hmm, this is usually controlled via runtime PM.


Takashi

> ---
>  sound/hda/codecs/senarytech.c | 37 +++++++++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 
> diff --git a/sound/hda/codecs/senarytech.c b/sound/hda/codecs/senarytech.c
> index 8ebd974817ac..c589b3b01171 100644
> --- a/sound/hda/codecs/senarytech.c
> +++ b/sound/hda/codecs/senarytech.c
> @@ -132,6 +132,36 @@ static void senary_init_verb(struct hda_codec *codec)
>  	snd_hda_override_pin_caps(codec, 0x19, 0x2124);
>  }
>  
> +static void senary_set_port_eapd(struct hda_codec *codec, hda_nid_t nid, bool enable)
> +{
> +	unsigned char port_eapd = 0, eapd_value = enable << 1;
> +
> +	port_eapd = snd_hda_codec_read(codec, nid, 0, 0xf0c, 0x0);
> +	if (port_eapd != eapd_value)
> +		snd_hda_codec_write(codec, nid, 0, 0x70c, eapd_value);
> +}
> +
> +static void senary_playback_hook(struct hda_pcm_stream *hinfo,
> +		struct hda_codec *codec,
> +		struct snd_pcm_substream *substream,
> +		int action)
> +{
> +	struct senary_spec *spec = codec->spec;
> +	struct auto_pin_cfg *cfg = &spec->gen.autocfg;
> +	int i;
> +
> +	switch (action) {
> +	case HDA_GEN_PCM_ACT_PREPARE:
> +		for (i = 0; i < cfg->speaker_outs; i++)
> +			senary_set_port_eapd(codec, cfg->speaker_pins[i], true);
> +		break;
> +	case HDA_GEN_PCM_ACT_CLEANUP:
> +		for (i = 0; i < cfg->speaker_outs; i++)
> +			senary_set_port_eapd(codec, cfg->speaker_pins[i], false);
> +		break;
> +	}
> +}
> +
>  static void senary_auto_turn_eapd(struct hda_codec *codec, int num_pins,
>  			      const hda_nid_t *pins, bool on)
>  {
> @@ -270,6 +300,13 @@ static int senary_probe(struct hda_codec *codec, const struct hda_device_id *id)
>  	if (err < 0)
>  		goto error;
>  
> +	/* Register playback hook for dynamic EAPD control.
> +	 * Vendor driver applies this specifically for subsystem 0x14f10101,
> +	 * but we apply it broadly for SN6186 to fix noise issues.
> +	 */
> +	if (codec->core.vendor_id == 0x1fa86186)
> +		spec->gen.pcm_playback_hook = senary_playback_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
>