几个月来，我一直在笔记本电脑上运行 Ubuntu 19.10，连接 Bose Soundsport 耳机没有任何问题。然而，从几天前开始，我无法使用默认的 GNOME 设置连接耳机。我改用bluetoothctlv5.50 bluez：
[bluetooth]# pair 4C:87:5D:B7:90:31
Attempting to pair with 4C:87:5D:B7:90:31
[CHG] Device 4C:87:5D:B7:90:31 Connected: yes
[CHG] Device 4C:87:5D:B7:90:31 UUIDs: 00000000-deca-fade-deca-deafdecacaff
[CHG] Device 4C:87:5D:B7:90:31 UUIDs: 00001101-0000-1000-8000-00805f9b34fb
[CHG] Device 4C:87:5D:B7:90:31 UUIDs: 00001108-0000-1000-8000-00805f9b34fb
[CHG] Device 4C:87:5D:B7:90:31 UUIDs: 0000110b-0000-1000-8000-00805f9b34fb
[CHG] Device 4C:87:5D:B7:90:31 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
[CHG] Device 4C:87:5D:B7:90:31 UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
[CHG] Device 4C:87:5D:B7:90:31 UUIDs: 0000111e-0000-1000-8000-00805f9b34fb
[CHG] Device 4C:87:5D:B7:90:31 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
[CHG] Device 4C:87:5D:B7:90:31 ServicesResolved: yes
[CHG] Device 4C:87:5D:B7:90:31 Paired: yes
Pairing successful
[CHG] Device 4C:87:5D:B7:90:31 ServicesResolved: no
[CHG] Device 4C:87:5D:B7:90:31 Connected: no
该设备似乎已配对但无法连接。如果我特意尝试连接该设备，则会发生以下情况：
[bluetooth]# connect 4C:87:5D:B7:90:31
Attempting to connect to 4C:87:5D:B7:90:31
[CHG] Device A8:6B:AD:1B:97:2A RSSI: -84
Failed to connect: org.bluez.Error.Failed
我已经pulseaudio-module-bluetooth安装了。systemctl出现以下错误：
● bluetooth.service - Bluetooth service
Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2020-03-08 13:18:34 HKT; 1min 15s ago
Docs: man:bluetoothd(8)
Main PID: 18813 (bluetoothd)
Status: "Running"
Tasks: 1 (limit: 4915)
Memory: 1.8M
CGroup: /system.slice/bluetooth.service
└─18813 /usr/lib/bluetooth/bluetoothd
Mar 08 13:18:34 hwpang-ideapad-s540 systemd[1]: Starting Bluetooth service...
Mar 08 13:18:34 hwpang-ideapad-s540 bluetoothd[18813]: Bluetooth daemon 5.50
Mar 08 13:18:34 hwpang-ideapad-s540 systemd[1]: Started Bluetooth service.
Mar 08 13:18:34 hwpang-ideapad-s540 bluetoothd[18813]: Starting SDP server
Mar 08 13:18:34 hwpang-ideapad-s540 bluetoothd[18813]: Bluetooth management interface 1.14 initialized
Mar 08 13:18:34 hwpang-ideapad-s540 bluetoothd[18813]: Endpoint registered: sender=:1.204 path=/MediaEndpoint/A2DPSink/sbc
Mar 08 13:18:34 hwpang-ideapad-s540 bluetoothd[18813]: Endpoint registered: sender=:1.204 path=/MediaEndpoint/A2DPSource/sbc
Mar 08 13:19:33 hwpang-ideapad-s540 bluetoothd[18813]: Unable to get Headset Voice gateway SDP record: Device or resource busy
Mar 08 13:19:33 hwpang-ideapad-s540 bluetoothd[18813]: connect error: Device or resource busy (16)
Mar 08 13:19:35 hwpang-ideapad-s540 bluetoothd[18813]: connect error: Device or resource busy (16)
有任何想法吗？