Bug#1136889: linux-image-6.12.88+deb13-amd64: Bluetooth broken after upgrade to 6.12.88

From	Waldemar Ladon <heos.magus@gmail.com>
Newsgroups	linux.debian.bugs.dist, linux.debian.kernel
Subject	Bug#1136889: linux-image-6.12.88+deb13-amd64: Bluetooth broken after upgrade to 6.12.88
Date	2026-05-17 11:10 +0200
Message-ID	<MVFFw-5MAJ-9@gated-at.bofh.it> (permalink)
References	<MVuqJ-5Eyc-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Cross-posted to 2 groups.

Show all headers | View raw

Source: linux
Version: 6.12.88+deb13-amd64
Followup-For: Bug #1136889
X-Debbugs-Cc: debian-amd64@lists.debian.org, heos.magus@gmail.com
User: debian-amd64@lists.debian.org
Usertags: amd64

Dear Maintainer,

*** Reporter, please consider answering these questions, where appropriate ***

   * What led up to the situation?
   * What exactly did you do (or not do) that was effective (or
     ineffective)?
   * What was the outcome of this action?
   * What outcome did you expect instead?

*** End of the template - remove these template lines ***


-- System Information:
Debian Release: 13.5
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 6.12.74+deb13+1-amd64 (SMP w/12 CPU threads; PREEMPT)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=pl_PL.UTF-8, LC_CTYPE=pl_PL.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled


Same issue reproduced here.

Hardware:
HP ProBook 465 G11
MediaTek MT7921 Bluetooth/Wi-Fi

Broken kernel:
6.12.88+deb13-amd64

Working kernel:
6.12.74+deb13+1-amd64

Symptoms:

* bluetoothctl: "No default controller available"
* btmgmt info: "Index list with 0 items"

Relevant dmesg output:
Bluetooth: hci0: Failed to send wmt func ctrl (-22)

Issue disappears completely after booting older kernel.

Firmware packages installed:

* firmware-mediatek
* firmware-linux
* firmware-linux-nonfree
* firmware-misc-nonfree

Troubleshooting attempted:

* restart bluetooth.service
* reload btusb/btmtk modules
* full poweroff
* unplugging USB hub/peripherals

Regression reproducible consistently on 6.12.88 only.

Back to linux.debian.kernel | Previous | Next | Find similar

Thread

Bug#1136889: linux-image-6.12.88+deb13-amd64: Bluetooth broken after upgrade to 6.12.88 Waldemar Ladon <heos.magus@gmail.com> - 2026-05-17 11:10 +0200

csiph-web