Re: [PATCH 0/2] ALSA: Don't share mixer->urb with the FCP/scarlett2 notification endpoint

[Takashi Iwai <tiwai@suse.de>]

On Sun, 09 Aug 2026 20:05:41 +0200,
Geoffrey D. Bennett wrote:
> 
> Hi Takashi,
> 
> Both the FCP and scarlett2 drivers used mixer->urb for their
> notification endpoint URB, but that field belongs to
> snd_usb_mixer_status_create() and is managed by mixer.c. Sharing it
> means the "already set up" check in the driver's init_notify() can be
> satisfied by the status endpoint's URB, so the driver's own URB is
> never submitted and the first command would crash in
> wait_for_completion_timeout() on the still-zeroed cmd_done. mixer.c
> can also kill, resubmit or free the URB from under the driver.
> 
> Give each driver its own URB in its private data. For scarlett2 this
> also means taking over the free/suspend/resume handling that mixer.c
> was doing for it.
> 
> Tested on an ISA C8X and a Scarlett 18i20 Gen 4 (FCP), and a Scarlett
> 4i4 Gen 3 and 4i4 Gen 4 (scarlett2) on 7.1.7, including suspend/resume
> and configuration save on suspend.
> 
> Thanks,
> Geoffrey
> 
> Geoffrey D. Bennett (2):
>   ALSA: FCP: Use a private URB for the notification endpoint
>   ALSA: scarlett2: Use a private URB for the notification endpoint

As those are no new regression, I applied both to for-next branch now.


thanks,

Takashi