Re: [PATCH 0/4] ALSA: caiaq: Kore controller fixes and LCD support

[Takashi Iwai <tiwai@suse.de>]

On Sun, 27 Sep 2026 02:35:28 +0200,
Niko Huuskonen wrote:
> 
> The Native Instruments Kore controllers (USB 17cc:4711 and 17cc:4712)
> work with snd-usb-caiaq, but a few things are wrong or missing:
> 
> - The EP1 command buffer is shared by all senders without locking.
>   Patch 1 adds a mutex. It is needed by patch 4, which adds a sender.
> 
> - Parts of the Kore key map do not match the hardware: softkeys 5-8
>   come in reverse order, and on the first Kore the knob touch sensors
>   are scrambled. Patch 2 fixes the map.
> 
> - The 128x64 LCD is not supported, and userspace cannot reach it while
>   the driver is bound. Patch 3 adds a hwdep interface ID, and patch 4
>   exposes the LCD as a hwdep device that takes whole frames, plus an
>   "LCD Contrast" control. The display protocol comes from USB captures
>   of the vendor software that the OpenKoreBridge project published.
> 
> Patch 2 changes the key codes userspace sees for softkeys 5-8 on both
> controllers, and for the touch sensors on the first Kore. Userspace
> that compensates for the old map, such as the OpenKoreBridge controller
> script, would have to follow. Userspace can read the map with
> EVIOCGKEYCODE to support kernels with and without the change. If
> changing the codes is a concern, patch 2 can be dropped; the rest of
> the series does not depend on it.
> 
> Testing: the series was tested on a Kore controller (17cc:4711), applied
> to v7.2.6 and built out of tree, with a userspace MIDI bridge that uses
> the LCD, the LEDs and all controls. Every patch builds with W=1, and
> checkpatch.pl --strict only asks whether MAINTAINERS needs updating for
> the new file, which the existing sound/usb/caiaq/ entry already covers.
> The locking problem in patch 1 was found by code review and has not
> been reproduced. A Kore 2 was not available for testing.
> 
> Tool use: the patches were written with an AI coding assistant (Claude,
> an LLM), as the Assisted-by tags say. It worked in an interactive
> session in which I asked it to make the Kore controller usable as a MIDI
> controller on Linux, to find out how its LCD is driven, to fix the
> button mapping I reported from testing the hardware, and to prepare the
> kernel changes for submission. It found the missing locking by code
> review, derived the key map from my tests on the controller, checked the
> LCD protocol on the device over raw USB, and tested each change on my
> controller.
> 
> Niko Huuskonen (4):
>   ALSA: caiaq: Serialize access to the EP1 command buffer
>   ALSA: caiaq: Fix the Kore controller key map
>   ALSA: uapi: Add hwdep interface ID for caiaq devices
>   ALSA: caiaq: Add LCD support for the Kore controllers

Applied all four patches to for-next branch.  Thanks.


Takashi