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

[Rong Zhang]

Hi Takashi,

Thanks for your review.

On Mon, 2026-03-02 at 10:59 +0100, Takashi Iwai wrote:
> 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.
> 

Thanks. I will send a v2 addressing that.

> 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?
> 

Sure.

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

Yeah. Patch 1-3 as a whole targets 7.1, where patch 1 is also for
backporting (so that potential insane volume ranges can still trigger a
warning in LTS, which is better than nothing).

Thanks,
Rong

> 
> Takashi