Re: [PATCH] ASoC: sophgo: return 1 on volume change in cv1800b_adc_volume_set()

[Inochi Amaoto <inochiama@gmail.com>]

On Mon, Jul 27, 2026 at 11:08:04AM +0530, kr494167@gmail.com wrote:
> From: Surendra Singh Chouhan <kr494167@gmail.com>
> 
> cv1800b_adc_volume_set() serves as the .put callback for the "Internal
> I2S Capture Volume" control.
> 
> ALSA mixer control callbacks must return 1 when the register value is
> modified, 0 if unchanged, or a negative error code on failure. Returning
> 0 unconditionally causes ALSA core to assume the value was unchanged,
> suppressing SNDRV_CTL_EVENT_MASK_VALUE change notifications to userspace
> sound servers (e.g. PipeWire/PulseAudio).
> 
> Fix this by comparing the new register value with the existing register
> value. If unchanged, return 0; otherwise, write the updated value and
> return 1.
> 
> Fixes: 4cf8752a03e6 ("ASoC: sophgo: add CV1800B internal ADC codec driver")
> Signed-off-by: Surendra Singh Chouhan <kr494167@gmail.com>
> ---

LGTM

Reviewed-by: Inochi Amaoto <inochiama@gmail.com>

>  sound/soc/sophgo/cv1800b-sound-adc.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/soc/sophgo/cv1800b-sound-adc.c b/sound/soc/sophgo/cv1800b-sound-adc.c
> index b66761156b99..bd93e261bdd1 100644
> --- a/sound/soc/sophgo/cv1800b-sound-adc.c
> +++ b/sound/soc/sophgo/cv1800b-sound-adc.c
> @@ -251,16 +251,22 @@ static int cv1800b_adc_volume_set(struct snd_kcontrol *kcontrol,
>  
>  	u32 v_left = clamp_t(u32, ucontrol->value.integer.value[0], 0, 24);
>  	u32 v_right = clamp_t(u32, ucontrol->value.integer.value[1], 0, 24);
> -	u32 val;
> +	u32 val, old_val;
>  
>  	val = readl(priv->regs + CV1800B_RXADC_ANA0);
> +	old_val = val;
> +
>  	val = u32_replace_bits(val, cv1800b_gains[v_left],
>  			       REG_COMB_LEFT_VOLUME);
>  	val = u32_replace_bits(val, cv1800b_gains[v_right],
>  			       REG_COMB_RIGHT_VOLUME);
> +
> +	if (val == old_val)
> +		return 0;
> +
>  	writel(val, priv->regs + CV1800B_RXADC_ANA0);
>  
> -	return 0;
> +	return 1;
>  }
>  
>  static DECLARE_TLV_DB_SCALE(cv1800b_volume_tlv, 0, 200, 0);
> -- 
> 2.55.0
>