Re: [PATCH 2/4] ALSA: usb-audio: Use fixed control index for us16x08 mixer elements

[Takashi Iwai]

On Tue, 13 Oct 2026 14:05:23 +0200,
Takashi Iwai wrote:
> 
> The callbacks for us16x08 mixer elements assume that id.index points
> to the channel to be operated, and the assumption is correct for now.
> However, since the kctls are added via snd_usb_mixer_add_control() and
> it looks for the empty slot if the same control name is already
> present, in theory, the index can become more than the channel numbers
> (if a conflicting name really happens).
> 
> Since the mixer code in us16x08 doesn't need the search for an empty
> slot but requires the fixed index, this patch changes slightly how to
> assign the kcontrols.  Now, a new argument is added to
> snd_usb_mixer_add_list() in order to disable the empty slot search,
> and use it in us16x08's add_new_ctl() helper function, instead.
> 
> Fixes: d2bb390a2081 ("ALSA: usb-audio: Tascam US-16x08 DSP mixer quirk")
> Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>

Obviously the main part to skip the empty-slot search was missing in
the patch :-<

Will resubmit v2 patch.


Takashi