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ASoC: qcom: sm8250: Limit RX digital gain to 0 dB

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The RX macro interpolator gains ("RX_RXn Digital Volume") run from
-84 dB to +40 dB. PipeWire and PulseAudio map full volume to the top of
a hardware control's range, so a UCM device that uses one of them as
its volume control plays 40 dB hot at 100% and clips.

Set a platform limit of 84 (0 dB) on the RX0, RX1 and RX2 interpolator
gains when the RX codec DMA link is initialised, the way the sc8280xp
and x1e80100 machine drivers limit their WSA gains. 0 dB is the default
of these controls and the value alsa-ucm-conf's rx-macro init sets, so
existing configurations are unaffected. A control that does not exist
on a board is skipped.

Signed-off-by: Filippo Falezza <effeffe99@gmail.com>
Reviewed-by: Prasad Kumpatla <prasad.kumpatla@oss.qualcomm.com>
Link: https://patch.msgid.link/20261027-sm8250-rx-gain-v1-1-386ee6d971db@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Filippo Falezza 2026-10-27 01:33:56 +00:00 committed by Mark Brown
parent d34a818a33
commit 55df188774
1 changed files with 10 additions and 0 deletions
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10
sound/soc/qcom/sm8250.c
View File

@ -39,6 +39,16 @@ static int sm8250_snd_init(struct snd_soc_pcm_runtime *rtd)
case USB_RX:
return qcom_snd_usb_offload_jack_setup(rtd, &data->usb_offload_jack,
&data->usb_offload_jack_setup);
case RX_CODEC_DMA_RX_0:
/*
* The RX macro digital gain goes up to +40 dB. Userspace that
* maps full volume to the top of the range (PipeWire, PulseAudio)
* would clip there, so stop the interpolator gains at 0 dB.
*/
snd_soc_limit_volume(rtd->card, "RX_RX0 Digital Volume", 84);
snd_soc_limit_volume(rtd->card, "RX_RX1 Digital Volume", 84);
snd_soc_limit_volume(rtd->card, "RX_RX2 Digital Volume", 84);
fallthrough;
default:
return qcom_snd_wcd_jack_setup(rtd, &data->jack, &data->jack_setup);
}