Re: [PATCH] USB Audio Class 2 Mixer unit support for GET_CUR, SET_CUR and RANGE

[Zipdox <zipdox@zipdox.net>]

On 9/28/26 12:59 PM, Takashi Iwai wrote:
>>  From a UX perspective, I would prefer if the lowest setting on the
>> control equals mute. This makes the most sense for a "mixer". Like I
>> mentioned before, extending the range down by 1 and making that
>> translate to -32768 seems like a convenient solution. When setting,
>> simply check if it's a mixer unit (UAC1 or UAC2, both do this) and if
>> the set value is equal to the minimum, and set the value to
>> -32768. For getting, check if it's a mixer unit and check if the
>> retrieved value is -32768, and then set the value to the minimum. The
>> only caveat is that the resolution might not align anymore with the
>> range. What do you think of this idea?
> 
> I thought of it, too.  OTOH, it'll be a bit tricky, because the range
> isn't usually covering -32767 but only a part.  So -32768 won't be
> reached continuously.
> 
> I'm inclined to have a simple mute switch in addition.
> 
> 
> thanks,
> 
> Takashi
> 
A mute switch could work if you add the necessary state management code. 
For now I think that's the most straightforward solution, seeing I don't 
know how ALSA would handle a misaligned range and resolution in the case 
of my proposal. Could you write a patch?