Public bug reported:
1) Release:
Ubuntu 24.04.4 LTS (24.04)
2) Package version:
linux-image-generic-hwe-24.04
Installed: 7.0.0-28.28~24.04.1
Candidate: 7.0.0-28.28~24.04.1
3) Expected behavior:
Bluetooth should discover nearby devices when scanning (bluetoothctl scan on),
as it did before this kernel update, on the same hardware.
4) Actual behavior:
Bluetooth device discovery fails completely. No devices are ever found, even
devices in active pairing mode nearby.
Hardware: Realtek RTL8852BU (USB combo Wi-Fi/Bluetooth), modalias
usb:v1D6Bp0246d0548.
Details:
- Bluetooth adapter is detected and powered normally (hci0, rfkill shows not
blocked).
- bluetoothd starts and runs without errors.
- Firmware loads successfully (dmesg shows "RTL: fw version 0xdbc6b20f", "AOSP
extensions version v1.00", "MGMT ver 1.23").
- However, "bluetoothctl scan on", "hcitool lescan", and "hcitool inq" all run
without error but never discover any nearby device.
- rmmod/modprobe of btusb and a full system reboot do not fix it.
- Disabling Wi-Fi (nmcli radio wifi off) to rule out coexistence issues did not
help either.
- Reinstalling linux-firmware and manually replacing rtl_bt/rtl8852bu_fw.bin
with the latest upstream firmware did not fix it either.
Workaround confirmed: booting into kernel 6.17.0-40-generic (also
installed on this system) restores normal Bluetooth scanning and
discovery immediately, with no other changes. This strongly suggests a
regression introduced in kernel 7.0.0-28-generic affecting Bluetooth
device discovery specifically for the RTL8852BU chipset, since the
firmware loads without error but the radio effectively stops discovering
anything at the HCI level.
System: Positivo Bahia VAIO (AMD Ryzen 7 5825U), BIOS v1.24.X.
ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: linux-image-7.0.0-28-generic 7.0.0-28.28~24.04.1
ProcVersionSignature: Ubuntu 6.17.0-40.40~24.04.1-generic 6.17.13
Uname: Linux 6.17.0-40-generic x86_64
ApportVersion: 2.28.2-0ubuntu0.1
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: leonardo 3162 F.... wireplumber
/dev/snd/controlC0: leonardo 3162 F.... wireplumber
/dev/snd/seq: leonardo 3157 F.... pipewire
CRDA: N/A
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Tue Jul 21 23:00:17 2026
InstallationDate: Installed on 2026-02-11 (161 days ago)
InstallationMedia: Ubuntu 24.04.3 LTS "Noble Numbat" - Release amd64
(20250805.1)
MachineType: Positivo Bahia - VAIO VJFE69F11X-B0221H
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
ProcFB: 0 amdgpudrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.17.0-40-generic
root=UUID=ec9f80e4-ef2a-4bf4-90f6-8ff170aa141b ro quiet splash vt.handoff=7
RelatedPackageVersions:
linux-restricted-modules-6.17.0-40-generic N/A
linux-backports-modules-6.17.0-40-generic N/A
linux-firmware 20240318.git3b128b60-0ubuntu2.27
SourcePackage: linux-hwe-7.0
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/19/2025
dmi.bios.release: 0.24
dmi.bios.version: V1.24.X
dmi.board.asset.tag: Default string
dmi.board.name: VJFE69B
dmi.board.vendor: Positivo Tecnologia SA
dmi.board.version: 11212313
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 10
dmi.chassis.vendor: Positivo Tecnologia SA
dmi.chassis.version: Default string
dmi.ec.firmware.release: 1.18
dmi.modalias:
dmi:bvn:bvrV1.24.X:bd06/19/2025:br0.24:efr1.18:svnPositivoBahia-VAIO:pnVJFE69F11X-B0221H:pvrDefaultstring:rvnPositivoTecnologiaSA:rnVJFE69B:rvr11212313:cvnPositivoTecnologiaSA:ct10:cvrDefaultstring:sku3344212:
dmi.product.family: VJFE69B
dmi.product.name: VJFE69F11X-B0221H
dmi.product.sku: 3344212
dmi.product.version: Default string
dmi.sys.vendor: Positivo Bahia - VAIO
** Affects: linux-hwe-7.0 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug noble wayland-session
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2161483
Title:
Bluetooth device discovery fails on RTL8852BU with kernel
7.0.0-28-generic (works fine on 6.17.0-40-generic)
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-hwe-7.0/+bug/2161483/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
