我刚刚在笔记本电脑 Dell Inspiron 3162 上安装了 Ubuntu 16.10（4.8.0-26-generic）。它有 2 个 USB 端口 - 2.0 和 3.0。
Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 5000M
Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/7p, 480M
另外，我有一个 WD 500 Gb usb 3.0 外置硬盘，格式化为一个 NTFS 分区。当我将其插入 usb 2.0 端口时，它工作正常，立即被识别和安装。但是当我将其插入 usb 3.0 端口时，什么也没发生。此端口仍可用于闪存驱动器、usb 鼠标，但不能用于此磁盘。lsusb 看到它：
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 5000M
|__ Port 1: Dev 3, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
和：
Bus 002 Device 003: ID 1058:074a Western Digital Technologies, Inc.
但是df看不到它。dmesg：
[ 5441.723330] usb 2-1: new SuperSpeed USB device number 3 using xhci_hcd
[ 5441.743845] usb 2-1: New USB device found, idVendor=1058, idProduct=074a
[ 5441.743855] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=5
[ 5441.743862] usb 2-1: Product: My Passport 074A
[ 5441.743869] usb 2-1: Manufacturer: Western Digital
[ 5441.743874] usb 2-1: SerialNumber: 575834314331323137333034
[ 5441.746816] usb-storage 2-1:1.0: USB Mass Storage device detected
[ 5441.751215] scsi host2: usb-storage 2-1:1.0
[ 5441.751406] scsi host2: runtime PM trying to activate child device host2 but parent (2-1:1.0) is not active
[ 5442.773507] scsi 2:0:0:0: Direct-Access WD My Passport 074A 1010 PQ: 0 ANSI: 6
[ 5442.774650] scsi 2:0:0:1: Enclosure WD SES Device 1010 PQ: 0 ANSI: 6
[ 5442.818861] sd 2:0:0:0: Attached scsi generic sg1 type 0
[ 5442.819781] ses 2:0:0:1: Attached Enclosure device
[ 5442.820437] ses 2:0:0:1: Attached scsi generic sg2 type 13
[ 5473.667703] usb 2-1: Disable of device-initiated U1 failed.
[ 5473.674129] usb 2-1: Disable of device-initiated U2 failed.
[ 5473.851619] usb 2-1: reset SuperSpeed USB device number 3 using xhci_hcd
[ 5473.872843] ses 2:0:0:1: Wrong diagnostic page; asked for 1 got 0
[ 5473.872852] ses 2:0:0:1: Failed to get diagnostic page 0xffffffea
[ 5473.872857] ses 2:0:0:1: Failed to bind enclosure -19
[ 5473.995525] usb 2-1: reset SuperSpeed USB device number 3 using xhci_hcd
[ 5504.504405] usb 2-1: reset SuperSpeed USB device number 3 using xhci_hcd
[ 5537.271975] usb 2-1: reset SuperSpeed USB device number 3 using xhci_hcd
[ 5570.040842] usb 2-1: reset SuperSpeed USB device number 3 using xhci_hcd