我在具有 4GB RAM 的 Rasberry Pi 4B 上安装了 64 位 Ubuntu Server 19.10。我还安装了 GUI 桌面。RP 4 使用蓝牙 5.0，Raspbian 操作系统可以使用该技术，但 Ubuntu 看不到已安装的蓝牙。是否有补丁可以让 Ubuntu 使用 RP 4 的板载蓝牙适配器？
tom@ubuntu:~$ lspci -knn | grep Net -A3; lsusb; dmesg | grep -i blue
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 413c:8505 Dell Computer Corp.
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
[ 12.336503] Bluetooth: Core ver 2.22
[ 12.336556] Bluetooth: HCI device and connection manager initialized
[ 12.336568] Bluetooth: HCI socket layer initialized
[ 12.336575] Bluetooth: L2CAP socket layer initialized
[ 12.336590] Bluetooth: SCO socket layer initialized
[ 41.499813] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 41.499819] Bluetooth: BNEP filters: protocol multicast
[ 41.499831] Bluetooth: BNEP socket layer initialized
tom@ubuntu:~$