我的主板后置 IO 面板上有 4 个 USB3 Gen1 端口，需要在 USB2 模式下运行才能在此机器上使用超过 32 个 USB 设备。
BIOS 设置似乎不起作用（设置XHCI Gen1为0），因为lsusb -tUbuntu 显示端口为5000M。
在 Ubuntu 中有没有办法将这些 USB3 端口设置为 USB2 来工作？
输出lsusb：
USB3 Gen1 端口仍显示为 USB3 Gen1 ( )，而 USB2 端口则按预期5000M被识别为 USB2 ( )。480M
$ lsusb -t
/: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 10000M
|__ Port 2: Dev 2, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 1: Dev 84, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 4: Dev 91, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 3: Dev 101, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 1: Dev 96, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 4: Dev 102, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 2: Dev 99, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 2: Dev 86, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 4: Dev 97, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 2: Dev 92, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 3: Dev 94, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 1: Dev 90, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 3: Dev 88, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 2: Dev 95, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 3: Dev 98, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 1: Dev 93, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 4: Dev 100, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 1: Dev 85, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 1: Dev 87, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 2: Dev 89, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 2: Dev 4, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 1: Dev 6, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 3: Dev 21, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 1: Dev 10, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 4: Dev 28, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 2: Dev 15, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 2: Dev 9, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 3: Dev 31, If 0, Class=Hub, Driver=hub/3p, 5000M
|__ Port 1: Dev 39, If 0, Class=Mass Storage, Driver=uas, 5000M
|__ Port 1: Dev 16, If 0, Class=Hub, Driver=hub/3p, 5000M
|__ Port 1: Dev 24, If 0, Class=Mass Storage, Driver=uas, 5000M
|__ Port 4: Dev 38, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 2: Dev 23, If 0, Class=Hub, Driver=hub/3p, 5000M
|__ Port 1: Dev 33, If 0, Class=Mass Storage, Driver=uas, 5000M
|__ Port 3: Dev 14, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 1: Dev 22, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 2: Dev 29, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 3: Dev 36, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 4: Dev 42, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 4: Dev 20, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 3: Dev 43, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 1: Dev 30, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 4: Dev 45, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 2: Dev 37, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 480M
|__ Port 2: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 31, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 32, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 36, If 0, Class=Mass Storage, Driver=usb-storage, 480M
|__ Port 2: Dev 33, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 35, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 4: Dev 37, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 2: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 12, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 7, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 4: Dev 15, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 2: Dev 10, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 2: Dev 16, If 0, Class=Hub, Driver=hub/3p, 480M
|__ Port 3: Dev 17, If 0, Class=Hub, Driver=hub/3p, 480M
|__ Port 1: Dev 13, If 0, Class=Hub, Driver=hub/3p, 480M
|__ Port 3: Dev 3, If 0, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 3: Dev 3, If 1, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 3: Dev 3, If 2, Class=Human Interface Device, Driver=usbhid, 12M
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 10000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 480M
|__ Port 5: Dev 42, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 46, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 43, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 4: Dev 51, If 0, Class=Mass Storage, Driver=usb-storage, 480M
|__ Port 2: Dev 47, If 0, Class=Mass Storage, Driver=usb-storage, 480M
|__ Port 3: Dev 49, If 0, Class=Mass Storage, Driver=usb-storage, 480M
|__ Port 1: Dev 45, If 0, Class=Mass Storage, Driver=usb-storage, 480M
|__ Port 4: Dev 48, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 4: Dev 54, If 0, Class=Mass Storage, Driver=usb-storage, 480M
|__ Port 2: Dev 52, If 0, Class=Mass Storage, Driver=usb-storage, 480M
|__ Port 3: Dev 53, If 0, Class=Mass Storage, Driver=usb-storage, 480M
|__ Port 1: Dev 50, If 0, Class=Mass Storage, Driver=usb-storage, 480M
|__ Port 2: Dev 44, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 7: Dev 3, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 8: Dev 5, If 0, Class=Human Interface Device, Driver=usbhid, 12M
但是，似乎lsusb显示 36 个 USB 存储驱动器，这是否意味着 USB3 端口已经作为 USB2 端口运行？
$ lsusb -t | grep storage -c
36