Bug#1137441: linux-image-6.12.88+deb13-amd64: Bluetooth won't load since updating to Linux 6.12.88-1

Package: linux-image-6.12.88+deb13-amd64
Version: 6.12.88-1
Severity: normal
X-Debbugs-Cc: [email protected]
User: [email protected]
Usertags: amd64

I updated one our our computers' Linux kernel (AFAICT, from
linux-image-6.12.73+deb13-amd64, but it's not impossible it was from
linux-image-6.12.86+deb13-amd64) to version
linux-image-6.12.88+deb13-amd64. Starting there, I started getting in the
boot messages:

    kernel: Bluetooth: hci0: Failed to send wmt func ctrl (-22)

Bluetooth cannot be enabled anymore; “bluetoothctl list” yields an empty
result.

Upgrading to kernel 7.0.7-1~bpo13+1 from Backports does not help;
downgrading to 6.12.73+deb13-amd64 restores functionality.

Thank you in advance!

 — Gunnar.

-- System Information:
Debian Release: forky/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 6.18.3+deb14-amd64 (SMP w/32 CPU threads; PREEMPT)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled