我花了一整天的时间来弄清楚为什么我的 Linux Mint 不再与我的蓝牙扬声器一起工作（几个月前还可以）。这个问题的好处是它让我终于更新了我的系统（即我运行的是 Linux Mint 19.3）。
felix@felix ~ $ bluetoothctl --version
bluetoothctl: 5.50
连接到我的扬声器可以正常工作，如果幸运的话，连接会保持几秒钟，我就可以听到声音。然而，在某些时候连接会中断。从日志来看，我认为整个蓝牙服务由于某种原因正在重新启动，因为这就是那一秒显示的内容：
Jun 1 22:42:43 felix kernel: [ 1358.725890] usb 3-7: USB disconnect, device number 11
Jun 1 22:42:43 felix acpid: input device has been disconnected, fd 18
Jun 1 22:42:43 felix bluetoothd[7507]: Endpoint unregistered: sender=:1.49 path=/MediaEndpoint/A2DPSource
Jun 1 22:42:43 felix bluetoothd[7507]: Endpoint unregistered: sender=:1.49 path=/MediaEndpoint/A2DPSink
Jun 1 22:42:44 felix NetworkManager[2472]: <info> [1591044163.9861] bluez5: NAP: removed interface AD:E9:25:D1:52:37
Jun 1 22:42:44 felix systemd[1]: Starting Load/Save RF Kill Switch Status...
Jun 1 22:42:44 felix systemd[1]: bluetooth.target: Unit not needed anymore. Stopping.
Jun 1 22:42:44 felix systemd[1]: Stopped target Bluetooth.
Jun 1 22:42:44 felix systemd-rfkill[7547]: Failed to open device rfkill9: No such device
Jun 1 22:42:44 felix systemd[1]: Started Load/Save RF Kill Switch Status.
Jun 1 22:42:44 felix kernel: [ 1359.001760] usb 3-7: new full-speed USB device number 12 using xhci_hcd
Jun 1 22:42:44 felix kernel: [ 1359.130692] usb 3-7: New USB device found, idVendor=8087, idProduct=07dc
Jun 1 22:42:44 felix kernel: [ 1359.130695] usb 3-7: New USB device strings: Mfr=0, Product=0, SerialNumber=0
Jun 1 22:42:44 felix kernel: [ 1359.144660] Bluetooth: hci0: read Intel version: 3707100180012d0d2a
Jun 1 22:42:44 felix kernel: [ 1359.144662] Bluetooth: hci0: Intel device is already patched. patch num: 2a
Jun 1 22:42:44 felix laptop-mode: enabled, not active
Jun 1 22:42:44 felix NetworkManager[2472]: <info> [1591044164.4263] bluez5: NAP: added interface AD:E9:25:D1:52:37
Jun 1 22:42:44 felix systemd[1]: Started Session c27 of user felix.
Jun 1 22:42:44 felix bluetoothd[7507]: Endpoint registered: sender=:1.49 path=/MediaEndpoint/A2DPSource
Jun 1 22:42:44 felix bluetoothd[7507]: Endpoint registered: sender=:1.49 path=/MediaEndpoint/A2DPSink
同样奇怪的是我没有连接或断开任何 USB 设备（如日志所示）。
蓝牙也不会被 rfkill 阻止：
felix@felix ~ $ rfkill list
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
2: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
有任何想法吗？