New: Bluetooth devices experience severe connection issues, frequent disconnections, and input lag in kernel 6.15.2, working fine in 6.15.1.

Bug 220398 [email protected] 1 participant 2 messages Aug 3, 2025 Bluetooth drivers

Share & tools

[email protected]

author

2025-08-03 00:16 UTC #0 lore raw

https://bugzilla.kernel.org/show_bug.cgi?id=220398

            Bug ID: 220398
           Summary: Bluetooth devices experience severe connection issues,
                    frequent disconnections, and input lag in kernel
                    6.15.2, working fine in 6.15.1.
           Product: Drivers
           Version: 2.5
          Hardware: AMD
                OS: Linux
            Status: NEW
          Severity: high
          Priority: P3
         Component: Bluetooth
          Assignee: [email protected]
          Reporter: [email protected]
        Regression: No

Bluetooth Regression Bug Report

Summary:
Bluetooth devices experience severe connection issues, frequent disconnections, and input lag in kernel 6.15.2, working fine in 6.15.1.

Kernel Versions:
- Last working: 6.15.1
- First broken: 6.15.2
- Confirmed broken through: 6.15.8 (latest tested)
- Distribution: Arch Linux (vanilla upstream kernel packages)

Hardware Information:

lsusb | grep -i bluetooth
Bus 003 Device 002: ID 0bda:2852 Realtek Semiconductor Corp. Bluetooth Radio

Tested bluetooth devices:
- Sony WH-1000XM5 headphones (audio cutoffs ~5 times every 3 seconds)
- Keychron K8 Pro keyboard (severe input lag, duplicate keystrokes)

Symptoms:
- Connection issues when pairing/connecting bluetooth devices
- Frequent disconnections even during active use
- Audio playback cuts off frequently with bluetooth headphones
- Severe input lag with bluetooth keyboards
- Multiple keystrokes being registered for single key presses
- Issues affect all bluetooth device types (keyboards, headphones, etc.)

Steps to Reproduce:
1. Connect any bluetooth device (keyboard, mouse, headphone)
2. Use device normally
3. Observe connection drops and input lag

Expected Behavior:
Stable bluetooth connections with normal input responsiveness (as seen in 6.15.1)

Actual Behavior:
Unreliable connections, frequent disconnects, severe input lag, duplicate keystrokes

Bisection Results:
Performed kernel bisection on Arch Linux:
- linux-6.15.1: Bluetooth works normally
- linux-6.15.2: Bluetooth exhibits all described issues
- Regression introduced between these exact versions

Error Logs:

dmesg output:

[    1.619605] usb 3-1: Product: Bluetooth Radio
[    6.641878] Bluetooth: Core ver 2.22
[    6.641900] NET: Registered PF_BLUETOOTH protocol family
[    6.641902] Bluetooth: HCI device and connection manager initialized
[    6.641905] Bluetooth: HCI socket layer initialized
[    6.641907] Bluetooth: L2CAP socket layer initialized
[    6.641912] Bluetooth: SCO socket layer initialized
[    6.761556] Bluetooth: hci0: RTL: examining hci_ver=0b hci_rev=000a
lmp_ver=0b lmp_subver=8852
[    6.763546] Bluetooth: hci0: RTL: rom_version status=0 version=1
[    6.763551] Bluetooth: hci0: RTL: loading rtl_bt/rtl8852au_fw.bin
[    6.764910] Bluetooth: hci0: RTL: loading rtl_bt/rtl8852au_config.bin
[    6.765011] Bluetooth: hci0: RTL: cfg_sz 6, total sz 64499
[    7.299548] Bluetooth: hci0: RTL: fw version 0xd9d617da
[    7.427557] Bluetooth: hci0: AOSP extensions version v1.00
[    7.427563] Bluetooth: hci0: AOSP quality report is supported
[    7.493922] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[    7.493926] Bluetooth: BNEP filters: protocol multicast
[    7.493930] Bluetooth: BNEP socket layer initialized
[    7.494833] Bluetooth: MGMT ver 1.23
[   24.601860] Bluetooth: RFCOMM TTY layer initialized
[   24.601867] Bluetooth: RFCOMM socket layer initialized
[   24.601871] Bluetooth: RFCOMM ver 1.11
[   51.185829] hid-sensor-hub 0005:054C:0DF0.0006: hidraw5: BLUETOOTH HID v2.41
Device [WH-1000XM5] on 10:6f:d9:24:c1:d2
[   71.308004] hid-generic 0005:3434:0280.0007: input,hidraw5: BLUETOOTH HID
v1.32 Keyboard [Keychron K8 Pro] on 10:6f:d9:24:c1:d2
[ 1577.292485] hid-generic 0005:3434:0280.0008: input,hidraw5: BLUETOOTH HID

v1.32 Keyboard [Keychron K8 Pro] on 10:6f:d9:24:c1:d2

journalctl output:

Aug 03 05:07:03 envy systemd[1]: Starting Bluetooth service...
Aug 03 05:07:03 envy (uetoothd)[564]: bluetooth.service: ConfigurationDirectory
'bluetooth' already exists but the mode is different. (File system: 755
ConfigurationDirectoryMode: 555)
Aug 03 05:07:03 envy bluetoothd[564]: Bluetooth daemon 5.83
Aug 03 05:07:03 envy systemd[1]: Started Bluetooth service.
Aug 03 05:07:03 envy bluetoothd[564]: Starting SDP server
Aug 03 05:07:03 envy bluetoothd[564]: Bluetooth management interface 1.23
initialized
Aug 03 05:07:03 envy bluetoothd[564]: Battery Provider Manager created
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/ldac
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSink/aptx_hd
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/aptx_hd
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSink/aptx
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/aptx
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSink/aac
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/aac
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSink/opus_g
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/opus_g
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSink/sbc
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/sbc
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/aptx_ll_1
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/aptx_ll_0
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/aptx_ll_duplex_1
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/aptx_ll_duplex_0
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/faststream
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/faststream_duplex
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSink/opus_05
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/opus_05
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSink/opus_05_duplex
Aug 03 05:07:20 envy bluetoothd[564]: Endpoint registered: sender=:1.28
path=/MediaEndpoint/A2DPSource/opus_05_duplex
Aug 03 05:07:54 envy bluetoothd[564]:
profiles/audio/avdtp.c:handle_unanswered_req() No reply to Close request
Aug 03 05:07:54 envy bluetoothd[564]: No matching connection for device

Additional Notes:
Issue is reproducible across different bluetooth devices and persists after:
- Bluetooth service restart
- Module reload (btusb)
- Clearing bluetooth cache
- Device re-pairing

Workaround: Using kernel 6.15.1 or linux-lts resolves all issues.

Signature · 4 lines

You may reply to this email to add a comment.

You are receiving this mail because:
You are the assignee for the bug.

[email protected]

author

2025-08-03 08:40 UTC #1 lore raw

[Bug 220398] Bluetooth devices experience severe connection issues, frequent disconnections, and input lag in kernel 6.15.2, working fine in 6.15.1.

https://bugzilla.kernel.org/show_bug.cgi?id=220398

Paul Menzel ([email protected]) changed:

What |Removed |Added
----------------------------------------------------------------------------

                 CC|                            |pmenzel+bugzilla.kernel.org
                   |                            |@molgen.mpg.de

--- Comment #1 from Paul Menzel ([email protected]) --- Thank you for the report. Looking through the commits between v6.15.1 and v6.15.2, the only Bluetooth change is related to Qualcomm:

    $ git log --oneline v6.15.1..v6.15.2 drivers/bluetooth/
    8b91e4b6b82b5 Bluetooth: hci_qca: move the SoC type check to the right
place

Too speed up fixing this, could you bisect the commit [1]?

https://docs.kernel.org/admin-guide/verify-bugs-and-bisect-regressions.html#v

Signature · 4 lines

You may reply to this email to add a comment.

You are receiving this mail because:
You are the assignee for the bug.