Re: [PATCH 0/4] usb-audio: fix mixer write failure handling

Takashi Iwai
2026-04-21T08:09:22Z

On Sun, 19 Apr 2026 22:30:28 +0200,
Cássio Gabriel wrote:
>
> This series fixes usb-audio mixer put() paths that currently report
> success even when the underlying device write fails.
>
> The issue exists in the generic mixer core callbacks, the Scarlett
> Gen1 enum path, and several Tascam US-16x08 put() callbacks.
>
> The US-16x08 EQ and compressor callbacks have an additional bug: they
> update their software shadow state before sending the USB write, so a
> failed transfer can leave later get() results out of sync with the
> hardware state.
>
> The series is split into four patches:
> - propagate write failures in the generic mixer core callbacks
> - fix the Scarlett Gen1 enum callback
> - propagate write failures in the simple US-16x08 put() callbacks
> - commit the US-16x08 EQ and compressor shadow state only after a
> successful write
>
> Successful writes are unchanged. Failed writes are now reported
> correctly, and the US-16x08 shadow state remains coherent with the
> hardware after write errors.
>
> Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>

As this might influence on the actual device behavior significantly,
and it's in a merge window, I postpone the series for 7.2.

thanks,

Takashi