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aesdef

Member

Registered: 2024-01-07

Posts: 2

Mediatek MT7921 is unable to load the bluetooth kernel module

Hello, using a Thinkpad t14 gen 1, on a recent update, bluetooth stopped working within KDE, it does not allow me to `enable` bluetooth anymore within the settings.

All was working fine until yesterday when I updated the system and rebooted.

The card is the `MEDIATEK Corp. MT7921`

On further investigation, `linux-firmware` and `bluez` are installed, and `bluetooth.service` is running.

`rmmod btusb` followed by `modprobe btusb` and `dmesg` reveals:

```
[  233.618020] bluetooth hci0: Direct firmware load for mediatek/BT_RAM_CODE_MT7961_1a_2_hdr.bin failed with error -2
[  233.618037] Bluetooth: hci0: Failed to load firmware file (-2)
[  233.618047] Bluetooth: hci0: Failed to set up firmware (-2)
[  233.618055] Bluetooth: hci0: HCI Enhanced Setup Synchronous Connection command is advertised, but not supported.
```

looking within `/usr/lib/firmware/mediatek` I can see:

```
BT_RAM_CODE_MT7922_1_1_hdr.bin.zst
BT_RAM_CODE_MT7961_1_2_hdr.bin.zst
...
```

The name of the bin files do not exactly match the filename of the output from dmesg, but I'm not sure if that's the problem or not because I noticed in the wiki that it does say that the MT7921 does use the BT_RAM_CODE_MT7961_1_2_hdr file.

# bluetoothctl show
No default controller available

yet we see the card is there ...

lspci -k

03:00.0 Network controller: MEDIATEK Corp. MT7921 802.11ax PCI Express Wireless Network Adapter
    Subsystem: Lenovo Device e0bc
    Kernel driver in use: mt7921e
    Kernel modules: mt7921e

So I think the firmware just isn't loading, like dmesg says, but I have no idea how to fix this. Does anyone know how I can resolve this?

Thanks

Last edited by aesdef (2024-05-21 10:00:35)

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Tomorrow never knows...

just4arch

Member

Registered: 2023-01-07

Posts: 125

Re: Mediatek MT7921 is unable to load the bluetooth kernel module

https://bbs.archlinux.org/viewtopic.php … 1#p2172391?

aesdef

Member

Registered: 2024-01-07

Posts: 2

Re: Mediatek MT7921 is unable to load the bluetooth kernel module

Confirmed, downgrading linux and linux-headers to 6.8.9 avoids the issue, for now.

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Tomorrow never knows...