Package: linux
Version: 6.12.88+deb13-amd64
Bluetooth USB adapter (Foxconn/MediaTek, 0489:e0cd) stops working
on kernels 6.12.86 and 6.12.88. Booting with 6.12.38 restores
functionality, confirming a regression.
Symptoms:
hciconfig hci0 shows DOWN and BD Address: 00:00:00:00:00:00
hciconfig hci0 up returns: Can't init device hci0: Invalid argument (22)
dmesg output (6.12.88):
Bluetooth: hci0: HW/SW Version: 0x008a008a, Build Time: 20241106151414
Bluetooth: hci0: Failed to send wmt func ctrl (-22)
Bluetooth: hci0: HCI Enhanced Setup Synchronous Connection command is
advertised, but not supported.
Hardware:
Bus 003 Device 003: ID 0489:e0cd Foxconn / Hon Hai MediaTek Bluetooth
Adapter
Driver: btmtkusb
WiFi: mt7921e (MediaTek combo chip, PCIe)
System: Debian 13.5, amd64
Kernels tested:
6.12.38+deb13-amd64 -- WORKS
6.12.86+deb13-amd64 -- FAILS
6.12.88+deb13-amd64 -- FAILS
Workaround: booting with 6.12.38 and pinning with apt-mark hold.
