Re: [PATCH v4] ALSA: usb-audio: Add quirks for Arturia AF16Rig

[Takashi Iwai <tiwai@suse.de>]

On Sat, 28 Mar 2026 12:08:41 +0100,
Phil Willoughby wrote:
> 
> The AF16Rig supports 34 channels at 44.1k/48k, 18 channels at 88.2k/96k
> and 10 channels at 176.4k/192k.
> 
> This quirks is necessary because the automatic probing process we would
> otherwise use fails. The root cause of that is that the AF16Rig clock is
> not readable (its descriptor says that it is but the reads fail).
> 
> Except as described below, the values in the audio format quirks were
> copied from the USB descriptors of the device. The rate information is
> from the datasheet of the device. The clock is the internal clock of the
> AF16Rig.
> 
> Tested-By: Phil Willoughby <willerz@gmail.com>
> I have tested all the configurations enabled by this patch.
> 
> Cc: Jaroslav Kysela <perex@perex.cz>
> Cc: Takashi Iwai <tiwai@suse.com>
> Signed-off-by: Phil Willoughby <willerz@gmail.com>

Thanks, applied to for-next branch now.

> ---
> Thank you all for your time and considered feedback.
> 
> There are two other clock sources the AF16Rig can use: an ADAT clock and
> a BNC word clock. In theory the correct support for those would be
> copies of these audioformat quirks with the clock changed to 43 (ADAT)
> or 44 (BNC). The reason that I did not include those quirks in this
> patch is that I cannot test them (because I do not have any other device
> that can act as an ADAT or BNC clock source).
> 
> I think that what I want to do is:
> 1. Macro-ise these quirks so the common stuff isn't repeated as much.
> This will be v5 of this patch.

This could be a good cleanup, yes.  You can submit as an incremental
cleanup.

> Then a separate patch where I:
> 2. Add the external clock quirks and locally test that it doesn't break
> anything for people who don't have the external clocks
> 3. Wrap the external clock quirks in #if 0 and a comment that they are
> disabled because they haven't been tested.
> 4. This will be marked signed-off but not tested-by me.

Hm, a better approach would be rather a creation of a mixer element to
switch the clock source, I suppose.  But it'll be more complex, of
course.


thanks,

Takashi