Dear Maintainer,

I am experiencing a reproducible USB audio regression with a MOTU M4 interface
on current Debian 13.

The interface has worked reliably for years. After rebooting into kernel
6.12.115+deb13.1-amd64, audio playback stopped working.

Booting the same system with kernel 6.12.113 restores normal operation. No
other configuration changes were made.

Hardware:
- CPU: AMD Ryzen 7 3700X
- USB controller: AMD Matisse USB 3.0 Host Controller [1022:149c]
- PCI address: 0000:0d:00.3
- Audio interface: MOTU M4 [07fd:000b]
- Device firmware: 2.05

Reproduction:

With PipeWire stopped, run:

speaker-test -D hw:0,0 -c 4 -r 48000 -F S32_LE -t sine

On kernel 6.12.115, playback fails with:

Write error: -5, Input/output error
xrun_recovery failed: -5
Write error: Input/output error

No audio is heard, and the MOTU M4 level meters show no activity.

The USB device enumerates normally, and ALSA recognizes the playback device. No
obvious USB errors appear in the kernel journal.

Kernel comparison:
- 6.12.111: working
- 6.12.113: working
- 6.12.115: broken
- 6.12.114: not tested

The problem occurs with direct ALSA playback, independently of PipeWire.

Best regards