Re: [PATCH 0/2] ALSA: usb-audio: Fix stale quirk control caches after write failures

[Takashi Iwai]

On Wed, 29 Apr 2026 15:20:00 +0200,
Cássio Gabriel wrote:
> 
> This series fixes stale software cache handling in several usb-audio
> mixer quirks.
> 
> A number of quirk callbacks update kcontrol->private_value before
> issuing vendor or class writes. When such a write fails, the driver can
> keep reporting and later replaying a value the device never accepted,
> because the corresponding get and resume paths consume the cached state.
> 
> - Patch 1 fixes the simple single-write quirk callbacks by restoring the
>   previous cache on error.
> - Patch 2 fixes the RME Babyface Pro packed-state callbacks by updating
>   the cache only after a successful write, since those helpers already
>   take explicit arguments and do not need private_value to be updated
>   before the USB request.
> 
> The split keeps the generic quirk fixes separate from the Babyface Pro
> packed-state logic and keeps each patch tied to its own introducing bug.
> 
> Signed-off-by: Cássio Gabriel <cassiogabrielcontato@xxxxxxxxx>
> ---
> Cássio Gabriel (2):
>       ALSA: usb-audio: Roll back quirk control caches on write errors
>       ALSA: usb-audio: Update Babyface Pro control caches only after successful writes

Applied both to for-next branch.  Thanks.


Takashi