Hello,
I would like to report a Bluetooth discovery issue that appears to be related to the MediaTek MT7902 BMediaTek MT7902 Bluetooth Cannot Discover Logitech Pebble 2 M350s (BLE) on CachyOSluetooth adapter.
System Information
Distribution: CachyOS
Kernel: 7.1.1-2-cachyos
Desktop Environment: KDE Plasma 6 (Wayland)
BlueZ Version: 5.86
Hardware
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Motherboard: ASUS PRIME A620M-F GAMING WIFI
-
Bluetooth Adapter: MediaTek MT7902 (onboard)
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Test Mouse: Logitech Pebble 2 M350s
-
Comparison Adapter: ASUS USB Bluetooth Dongle (Realtek chipset)
PCI device:
MediaTek MT7902 [14c3:7902]
Problem Description
My Logitech Pebble 2 M350s Bluetooth mouse cannot be discovered by the onboard MediaTek MT7902 adapter.
The mouse is placed into pairing mode correctly, but it never appears during Bluetooth scans.
Comparison Tests
The same mouse is immediately detected by:
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Android phones
-
ASUS USB Bluetooth adapter with a Realtek chipset
This indicates that the mouse itself is functioning correctly.
In addition, the MT7902 adapter is able to discover and connect to other Bluetooth devices, including:
-
JBL Bluetooth speaker
-
LG Smart TV
Therefore, the issue appears to be specific to BLE device discovery rather than Bluetooth functionality in general.
Additional Context
MT7902 Bluetooth support was only recently integrated into the upstream Linux kernel and became available through recent kernel updates.
Because the Bluetooth support for this chipset is relatively new, I am wondering whether there are still unresolved compatibility issues affecting certain BLE devices.
Bluetooth Controller Status
The controller is detected correctly and appears fully operational:
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Powered: Yes
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Pairable: Yes
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Roles: Central and Peripheral
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BLE advertising capabilities detected correctly
Log Messages
The Bluetooth daemon repeatedly reports:
Failed to set default system config for hci0
and numerous messages similar to:
Unable to load key file from /var/lib/bluetooth/...
Unable set contents for /var/lib/bluetooth/...
I am not sure whether these messages are related to the discovery issue, but I am including them for completeness.
Results Summary
| Device | MT7902 Onboard | ASUS Realtek USB Dongle |
|---|---|---|
| Logitech Pebble 2 M350s | Not discovered | Discovered immediately |
| JBL Speaker | Works | Works |
| LG TV | Works | Works |
| Android Phone Test | Mouse discovered immediately | Mouse discovered immediately |
Additional Testing
I performed additional testing with other Bluetooth peripherals.
An Apple Magic Mouse is discovered and works correctly with the onboard MT7902 adapter.
This suggests that BLE functionality is not completely broken on the MT7902.
The issue currently appears to be specific to the Logitech Pebble 2 M350s, which is never discovered by the MT7902 adapter while being immediately discoverable by Android phones and an ASUS Realtek-based USB Bluetooth adapter.
Question
Has anyone using MT7902 hardware experienced similar BLE discovery issues?
Any suggestions for additional debugging or testing would be greatly appreciated.
Thank you.