Thinkpad E450 Ubuntu 24.04 蓝牙突然罢工，设置页面蓝牙无法激活(turn on失效）。
网上搜索诸多帖子试了一遍都没有解决，直到拜读到这篇[Solved] Bluetooth down and hciconfig hci0 up timeout / Kernel & Hardware / Arch Linux Forums
适用于我的问题，并完美解决我的问题。
andy@ThinkPad:~/Desktop$ sudo hciconfig hci0 down
andy@ThinkPad:~/Desktop$ sudo rmmod btusb
andy@ThinkPad:~/Desktop$ sudo modprobe btusb
andy@ThinkPad:~/Desktop$ sudo hciconfig hci0 up
andy@ThinkPad:~/Desktop$ sudo hcitool dev
Devices:
hci0 E4:F8:9C:74:B4:08
找回设备hci0信息之后，返回设置，蓝牙终于可以打开。
之前无论如何点击打开，始终返回提示蓝牙未打开，查询日志返回如下信息：
andy@ThinkPad:~/Desktop$ sudo dmesg | grep -i bluetooth
[ 3.768396] Bluetooth: Core ver 2.22
[ 3.768433] NET: Registered PF_BLUETOOTH protocol family
[ 3.768436] Bluetooth: HCI device and connection manager initialized
[ 3.768441] Bluetooth: HCI socket layer initialized
[ 3.768445] Bluetooth: L2CAP socket layer initialized
[ 3.768450] Bluetooth: SCO socket layer initialized
[ 3.945823] thinkpad_acpi: rfkill switch tpacpi_bluetooth_sw: radio is unblocked
[ 6.048395] Bluetooth: hci0: command 0x0c03 tx timeout
[ 6.048413] Bluetooth: hci0: sending initial HCI reset failed (-110)
[ 10.623611] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 10.623620] Bluetooth: BNEP filters: protocol multicast
[ 10.623627] Bluetooth: BNEP socket layer initialized