Re: [PATCH 0/9] ALSA: usb-audio: Add quirks for linear volume devices and deconflict VID

[Takashi Iwai <tiwai@suse.de>]

On Sun, 01 Mar 2026 22:37:16 +0100,
Rong Zhang wrote:
> 
> Some quirky devices tune their volume by linearly tuning the voltage
> level (linear volume). In other words, such devices has a linear TLV
> mapping of DECLARE_TLV_DB_LINEAR(scale, TLV_DB_GAIN_MUTE, 0).
> 
> The series mainly adds quirk flags MIXER_PLAYBACK_LINEAR_VOL and
> MIXER_CAPTURE_LINEAR_VOL to represent this case respectively for
> playback and capture mixers. Afterward, apply these quirk flags on them.
> 
> Some MV-SILICON devices with these quirks also have another quirk: VID
> conflicts with Focusrite Novation (0x1235). Hence, add support for
> string-descriptor-based quirk table entries and define an entry for MV-
> SILICON to deconflict them.
> 
> Some improvements to the logic of volume range checks is also included
> in the series to help identify quirky devices with linear volume.
> 
> Rong Zhang (9):
>   Revert "ALSA: usb: Increase volume range that triggers a warning"
>   ALSA: usb-audio: Add helper function for volume range checks
>   ALSA: usb-audio: Improve volume range checks
>   ALSA: usb-audio: Support string-descriptor-based quirk table entry
>   ALSA: usb-audio: Deconflict VID between Focusrite Novation &
>     MV-SILICON
>   ALSA: doc: Add doc for QUIRK_FLAG_SKIP_IFACE_SETUP of snd-usb-audio
>   ALSA: usb-audio: Add QUIRK_FLAG_MIXER_{PLAYBACK,CAPTURE}_LINEAR_VOL
>   ALSA: usb-audio: Add linear volume quirk for Hotone Audio Pulze Mini
>   ALSA: usb-audio: Apply linear volume quirk on MV-SILICON devices

Thanks for patches!  The logic looks good and the implementation
seems reasonable.  One slight concern was about the string matching
patch (I explained in another mail), but others look fine.

Maybe the patch to add the missing documentation for
QUIRK_FLAG_SKIP_IFACE_SETUP should be applied individually beforehand.
Could you send it a fix for 7.0?

The revert of volume range check makes sense, but maybe that should be
combined with your rest changes.


Takashi