Re: [PATCH v2] ALSA: hda/realtek: Limit Line In boost and ADC gain on DECENTA MATX03
From: Takashi Iwai
Date: Thu Oct 15 2026 - 03:24:05 EST
On Thu, 15 Oct 2026 04:12:10 +0200,
wangdich9700@xxxxxxx wrote:
>
> From: wangdicheng <wangdicheng@xxxxxxxxxx>
>
> The DECENTA MATX03 (ALC897, SSID 1e0b:1297) exposes a high gain
> range on both the Line In pin boost and the ADC input amp. Pin 0x1a
> reports nsteps=0x03 with stepsize=0x27, that is 0, 9.75, 19.5 and
> 29.25 dB. ADC 0x08 reports nsteps=0x3f with stepsize=0x02, that is
> 0 to 31.5 dB in 0.5 dB steps, and defaults to 0x3f (maximum). The
> combined 60.75 dB analogue cascade overloads the front-end when the
> source level is high, producing audible noise during Line In
> monitoring.
>
> Add a new fixup alc897_fixup_limit_linein_boost that overrides the
> amp capabilities of pin 0x1a to nsteps=1 (max ~11.75 dB) and ADC
> 0x08 to nsteps=1 (max ~0.5 dB). The total gain drops from 60.75 dB
> to ~12.25 dB, eliminating the clipping.
>
> Signed-off-by: wangdicheng <wangdicheng@xxxxxxxxxx>
Applied to for-next branch. Thanks.
Takashi