最後更新: 2021-09-19

目錄

• 情況 1 - USB Disk
• 情況 2 - 同一個 Hub 上有多個 Device

情況 1

Step 0: 查看 USB Disk Info

lsusb

Bus 004 Device 002: ID 152d:9561 JMicron Technology Corp. / JMicron USA Technology Corp. JMS56x Series
...

lsusb -t

/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 5000M
    |__ Port 1: Dev 2, If 0, Class=Mass Storage, Driver=uas, 5000M
...

Step 1: Verify hub info.

cd /sys/bus/usb/drivers/usb

ls -l

# Bus 04 的 Port 1
4-1 -> ../../../../devices/pci0000:00/0000:00:1c.3/0000:04:00.0/usb4/4-1/

cat 4-1/{idVendor,idProduct}

152d
9561

Step 2: To turn off power on all USB ports of a hub

# bind – enable the Root Hub

# unbind – disable the Root Hub

# 在 /sys/bus/usb/drivers/usb 內

# Format: Bus:Port

echo "4-1" > unbind

Step 3: To turn power back on - you may bind it back using

echo "4-1" > bind

情況 2 - 同一個 Hub 上有多個 Device

# 查看情況

lsusb -t

/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/6p, 480M
        |__ Port 4: Dev 8, If 0, Class=Mass Storage, Driver=uas, 480M
        |__ Port 6: Dev 9, If 0, Class=Hub, Driver=hub/6p, 480M

ls /sys/bus/usb/drivers/usb

lrwxrwxrwx 1 root root    0 Jun  9 13:25 1-1 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1
lrwxrwxrwx 1 root root    0 Jun  9 13:25 1-1.4 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.4
lrwxrwxrwx 1 root root    0 Jun  9 13:25 1-1.6 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.6

reset Hub 上其中一個 device

cd /sys/bus/usb/drivers/usb

# "1-1.4" 的 soft-link 會消失

echo "1-1.4" > unbind

整個 Hub reset

# "1-1", "1-1.4", "1-1.6" 的 soft-link 會消失

echo "1-1" > unbind