Re: [PATCH 0/5] ALSA: usb-audio: Audient iD14 MkI vendor controls

[Takashi Iwai <tiwai@suse.de>]

On Tue, 20 Oct 2026 01:01:54 +0200,
Will Porter wrote:
> 
> The Audient iD14 MkI (2708:0002) keeps its monitor section, output
> routing, mixer and input options on vendor extension units. It also
> uses feature units whose descriptors declare no controls. On Linux a
> user cannot change the routing. The device powers up with every output
> on DAW Thru, which bypasses the volume knob.
> 
> This series adds those controls in a new mixer_audient_id.c, one group
> per patch. A MkI-only name map hides the generic controls that each
> group replaces. The MkII keeps audient_id14_map.
> 
> Scope: only the iD14 MkI is supported, and only its USB ID reaches the
> new code. Other Audient iD models keep the generic driver. Their units
> may differ, and this series does not cover them. The file follows
> mixer_scarlett2.c, which began with one model and added others through
> per-model tables. Names with id14_ hold the MkI's unit IDs and tables. A
> later iD model can add its own tables to this file.
> 
> sound for-next also has mixer_evo.c for the Audient EVO 4 (2708:0006).
> EVO and iD are separate Audient product lines. The iD14 MkI uses other
> units and a larger control set: a monitor controller, output routing, a
> 14 x 4 mixer and write-only controls. So this series keeps the iD line
> in its own file.
> 
> At probe the driver writes only controls that it cannot read back: the
> write-only controls (patch 4) and FU 12 (patch 5). They get the launch
> values of Audient's iD application. If a probe write fails, the control
> shows the fallback value that those patches describe. The driver does
> not write the routing or the mix. User space (alsactl, an application)
> sets the rest of the iD application's launch state.
> 
> There is no resume code. Every write to a write-only control reaches
> the device, so alsactl restore also repairs a device that was reset.
> The state across a suspend depends on the power source:
> - On USB bus power, a system suspend re-enumerates the device.
> - With its mains adapter connected, the device keeps its state across a
>   system suspend. This is also true when the host controller resets the
>   device and the card stays. The sampled readable controls did not
>   change.
> - A runtime suspend left the readable controls unchanged on both power
>   sources, with no reset logged. A runtime suspend is possible only
>   after usbhid releases the HID interface.
> 
> Patch 5 replaces the generic "Monitor Mix Playback Volume" (FU 12) with
> one of the same name, count and range. FU 12 GET CUR returns stale data
> from other units. Its Main L channel ignores writes, but Main R applies
> them. audient_id14_map already notes this asymmetry. The new control
> holds Main at 0 dB. This is a deliberate change for existing users: a
> Main R attenuation set through the generic control no longer applies.
> 
> The protocol comes from Audient's iD application (version 4.4.5 for
> macOS). USB captures of the application confirmed it.
> 
> Test setup:
> - iD14 MkI, firmware 1.1.1
> - Bazzite 44, kernel 7.2.9-ogc3.1.fc44
> - snd-usb-audio built out of tree from the v7.2.9 sound/usb sources
>   with this series applied
> 
> Tests:
> - listening tests: routing, dim, talkback, Cue
> - a loopback cable: gain boost, polarity, FU 12 per channel
> - alsactl store and restore across a replug
> - an out-of-list routing value
> - a runtime suspend
> - three system suspends (S3) with control reads running at about 3000
>   per second: no read failed after a resume
> - the optical power-on mode, read on macOS 27.0.1 with no Audient
>   software running
> 
> The series is based on sound for-next a4ef328ce3b3. Each patch builds
> on its own there with make W=1 sound/usb/. The hardware tests used the
> complete series on 7.2.9 sources, where snd_usb_mixer_add_list() has no
> look_for_empty argument. The series passes true, which keeps that
> behaviour.
> 
> Will Porter (5):
>   ALSA: usb-audio: Give the Audient iD14 MkI its own mixer map
>   ALSA: usb-audio: Add Audient iD14 MkI monitor and routing controls
>   ALSA: usb-audio: Add Audient iD14 MkI mixer matrix
>   ALSA: usb-audio: Add Audient iD14 MkI write-only controls
>   ALSA: usb-audio: Replace the Audient iD14 MkI FU 12 control
> 
>  sound/usb/Makefile           |   1 +
>  sound/usb/mixer_audient_id.c | 790 +++++++++++++++++++++++++++++++++++
>  sound/usb/mixer_audient_id.h |   7 +
>  sound/usb/mixer_maps.c       |  10 +-
>  sound/usb/mixer_quirks.c     |   4 +
>  5 files changed, 811 insertions(+), 1 deletion(-)
>  create mode 100644 sound/usb/mixer_audient_id.c
>  create mode 100644 sound/usb/mixer_audient_id.h

FYI, I postpone this to 7.5, as 7.4 merge window was already opened
and this PR has too big changes as a last-minute fix.


thanks,

Takashi