Ubuntu – Unplug and plug in again a USB device in the terminal

command linemouseusbwireless

For years, I have been dealing with this Ubuntu bug where my mouse freezes soon after booting and then periodically freezes after that. To fix it, I have to physically unplug the usb transceiver for the mouse and plug it back in. From my research, this bug happens with USB wireless Windows mice when dual booting Linux and Windows.

Is there a way I can programmatically (from the terminal) unplug the USB transceiver instead of doing it physically? I want to achieve this in my startup bash script.

I'm using Ubuntu 16.04

Edit: I solved my problem but it doesn't really relate to my question.

In the file..

/etc/laptop-mode/conf.d/runtime-pm.conf

I had to make 

CONTROL_RUNTIME_AUTOSUSPEND=0

This fixes the mouse bug I was experiencing for years.

Best Answer

I wrote a script to show how I’d do that:

#!/bin/bash

port="1-1.1" # as shown by lsusb -t: {bus}-{port}(.{subport})

bind_usb() {
  echo "$1" >/sys/bus/usb/drivers/usb/bind
}

unbind_usb() {
  echo "$1" >/sys/bus/usb/drivers/usb/unbind
}

unbind_usb "$port"
# sleep 1 # enable delay here
bind_usb "$port"

First you need to get the bus and port number of the usb port in question. You can do that with lsusb and any device you recognize in lsusb’s output, I use a Sandisk pendrive here:

$ lsusb
Bus 001 Device 005: ID 04f2:b39a Chicony Electronics Co., Ltd 
Bus 001 Device 112: ID 8087:07dc Intel Corp. 
Bus 001 Device 019: ID 04d9:1603 Holtek Semiconductor, Inc. Keyboard
Bus 001 Device 018: ID 0424:2504 Standard Microsystems Corp. USB 2.0 Hub
Bus 001 Device 022: ID 0781:5567 SanDisk Corp. Cruzer Blade
Bus 001 Device 002: ID 8087:8000 Intel Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
$ lsusb -t
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/3p, 480M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/8p, 480M
        |__ Port 1: Dev 22, If 0, Class=Mass Storage, Driver=usb-storage, 480M
        |__ Port 2: Dev 18, If 0, Class=Hub, Driver=hub/4p, 480M
            |__ Port 1: Dev 19, If 1, Class=Human Interface Device, Driver=usbhid, 1.5M
            |__ Port 1: Dev 19, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M
        |__ Port 7: Dev 112, If 0, Class=Wireless, Driver=btusb, 12M
        |__ Port 7: Dev 112, If 1, Class=Wireless, Driver=btusb, 12M
        |__ Port 8: Dev 5, If 1, Class=Video, Driver=uvcvideo, 480M
        |__ Port 8: Dev 5, If 0, Class=Video, Driver=uvcvideo, 480M

From the output of lsusb you get the bus and device number of the device, then search this device in the output of lsusb -t to get the bus and port number (sometimes with subports). The syntax is:

1-2.3 # for Bus 1 Port 2 Subport 3 – strip leading zeroes!

Use this as port in the script. Now you just need to make it executable with chmod +x /path/to/script and run it with root permissions:

sudo /path/to/script

I didn’t need one for my pendrive, but it may be necessary for you to add a delay between unbinding and binding again, that’s what the commented out sleep 1 line is for – you can experiment with the values, e.g. sleep 0.5 for half a second.

Note that this approach shows how to disable and enable again a certain USB port, if you want a specific device to be unbound and rebound again you’ll have to use the same USB port for this to work. One could think of a way to parse lsusb’s output to dynamically get the bus and port number of a specific device every time the script is called, this would allow you to use any USB port, but I feel that would be an overkill here.

Suggestions taken from this linux.com blog article.

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