In a troubleshooting thread[1] I assisted with in the local Ubuntu community a user encountered an issue where bluetooth devices(e.g. HID mouse) no longer function after a certain update on a Xubuntu 22.04 system that uses a HWE kernel.
bluetoothd logs appear to have some error messages like:
```
Bluetooth management interfae 1.22 initialized
src/adapter.c:reset_adv_monitors_complete() Failed to reset Adv monitors: Failed (0x03)
Failed to clear UUIDs: Failed (0x03)
Failed to add UUID: Failed (0x03)
Failed to add UUID: Failed (0x03)
Failed to add UUID: Failed (0x03)
Endpoint registered: sender=1.32 path=/MediaEndpoint/A2DPSource/ldac
```
```
Endpoint registered: sender=1.46 path=/MediaEndpoint/A2DPSource/sbc_xq_552
src/device.c:load_gatt_db() no cache for D1:2B:38:RE:DA:CT
src/service.c:service_accept() input-hog profile accept failed for D1:2B:38:RE:DA:CT
src/device.c:load_gatt_db() no cache for D1:2B:38:RE:DA:CT
src/service.c:service_accept() input-hog profile accept failed for D1:2B:38:RE:DA:CT
src/device.c:load_gatt_db() no cache for D1:2B:38:RE:DA:CT
src/service.c:service_accept() input-hog profile accept failed for D1:2B:38:RE:DA:CT
```
```
Bluetooth: hci0: unexpected cc 0x0c7c length: 1 < 3
Bluetooth: hci0: unexpected SMP command 0x06 from D1:2B:38:RE:DA:CT
Bluetooth: hci0: unexpected SMP command 0x07 from D1:2B:38:RE:DA:CT
Bluetooth: hci0: unexpected SMP command 0x08 from D1:2B:38:RE:DA:CT
Bluetooth: hci0: unexpected SMP command 0x09 from D1:2B:38:RE:DA:CT
```
The Bluetooth controller seems to be manufactured by Realtek(VendorID=0bda), however I unable to find the exact model number of the hardware(ProductID=b00a).
Downgrade the linux-firmware package to 20220329.git681281e4-0ubuntu3.14 doesn't fix the issue, however when the kernel is downgraded from 6.5.0-17-generic to 5.15.0-94-generic the issue is no longer reproduced, which appears to be a regression in the kernel and/or the Bluetooth stack instead of the device firmware.
As I'm not really the one who reproduce this issue I can only document the gathered information here, though there are users in other distros encountered similar problems on 6.x kernel:
In a troubleshooting thread[1] I assisted with in the local Ubuntu community a user encountered an issue where bluetooth devices(e.g. HID mouse) no longer function after a certain update on a Xubuntu 22.04 system that uses a HWE kernel.
bluetoothd logs appear to have some error messages like:
``` c:reset_ adv_monitors_ complete( ) Failed to reset Adv monitors: Failed (0x03) oint/A2DPSource /ldac
Bluetooth management interfae 1.22 initialized
src/adapter.
Failed to clear UUIDs: Failed (0x03)
Failed to add UUID: Failed (0x03)
Failed to add UUID: Failed (0x03)
Failed to add UUID: Failed (0x03)
Endpoint registered: sender=1.32 path=/MediaEndp
```
``` oint/A2DPSource /sbc_xq_ 552 c:load_ gatt_db( ) no cache for D1:2B:38:RE:DA:CT c:service_ accept( ) input-hog profile accept failed for D1:2B:38:RE:DA:CT c:load_ gatt_db( ) no cache for D1:2B:38:RE:DA:CT c:service_ accept( ) input-hog profile accept failed for D1:2B:38:RE:DA:CT c:load_ gatt_db( ) no cache for D1:2B:38:RE:DA:CT c:service_ accept( ) input-hog profile accept failed for D1:2B:38:RE:DA:CT
Endpoint registered: sender=1.46 path=/MediaEndp
src/device.
src/service.
src/device.
src/service.
src/device.
src/service.
```
```
Bluetooth: hci0: unexpected cc 0x0c7c length: 1 < 3
Bluetooth: hci0: unexpected SMP command 0x06 from D1:2B:38:RE:DA:CT
Bluetooth: hci0: unexpected SMP command 0x07 from D1:2B:38:RE:DA:CT
Bluetooth: hci0: unexpected SMP command 0x08 from D1:2B:38:RE:DA:CT
Bluetooth: hci0: unexpected SMP command 0x09 from D1:2B:38:RE:DA:CT
```
The Bluetooth controller seems to be manufactured by Realtek( VendorID= 0bda), however I unable to find the exact model number of the hardware( ProductID= b00a).
Downgrade the linux-firmware package to 20220329. git681281e4- 0ubuntu3. 14 doesn't fix the issue, however when the kernel is downgraded from 6.5.0-17-generic to 5.15.0-94-generic the issue is no longer reproduced, which appears to be a regression in the kernel and/or the Bluetooth stack instead of the device firmware.
As I'm not really the one who reproduce this issue I can only document the gathered information here, though there are users in other distros encountered similar problems on 6.x kernel:
Bluetoothd errors since kernel 6.x : archlinux /www.reddit. com/r/archlinux /comments/ 16e9aks/ bluetoothd_ errors_ since_kernel_ 6x/
https:/
[1] https:/ /t.me/x_ ubuntu_ taiwan_ community/ 111326