How do you reset a USB device from the command line?

Question

Is it possible to reset the connection of a USB device, without physically disconnecting/connecting from the PC?

Specifically, my device is a digital camera. I'm using gphoto2, but lately I get "device read errors", so I'd like to try to do a software-reset of the connection.

From what I can tell, there are no kernel modules being loaded for the camera. The only one that looks related is usbhid.

Answer 1

Save the following as usbreset.c

/* usbreset -- send a USB port reset to a USB device */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>

#include <linux/usbdevice_fs.h>


int main(int argc, char **argv)
{
    const char *filename;
    int fd;
    int rc;

    if (argc != 2) {
        fprintf(stderr, "Usage: usbreset device-filename\n");
        return 1;
    }
    filename = argv[1];

    fd = open(filename, O_WRONLY);
    if (fd < 0) {
        perror("Error opening output file");
        return 1;
    }

    printf("Resetting USB device %s\n", filename);
    rc = ioctl(fd, USBDEVFS_RESET, 0);
    if (rc < 0) {
        perror("Error in ioctl");
        return 1;
    }
    printf("Reset successful\n");

    close(fd);
    return 0;
}

The run the following commands in terminal:

1. Compile the program:

   $ cc usbreset.c -o usbreset
   

2. Get the Bus and Device ID of the USB device you want to reset:

   $ lsusb  
   Bus 002 Device 003: ID 0fe9:9010 DVICO  
   

3. Make our compiled program executable:

   $ chmod +x usbreset
   

4. Execute the program with sudo privilege; make necessary substitution for <Bus> and <Device> ids as found by running the lsusb command:

   $ sudo ./usbreset /dev/bus/usb/002/003  
   

---

Source of above program: http://marc.info/?l=linux-usb&m=121459435621262&w=2

Answer 2

I haven't found myself in your specific circumstances before, so I'm not sure if it'll do enough, but the simplest way I've found to reset a USB device is this command: (No external apps necessary)

sudo sh -c "echo 0 > /sys/bus/usb/devices/1-4.6/authorized"
sudo sh -c "echo 1 > /sys/bus/usb/devices/1-4.6/authorized"

That's the actual one I use to reset my Kinect since libfreenect seems to have no API for putting it back to sleep. It's on my Gentoo box, but the kernel should be new enough to use the same path structure for sysfs.

Yours obviously wouldn't be 1-4.6 but you can either pull that device path from your kernel log (dmesg) or you can use something like lsusb to get the vendor and product IDs and then use a quick command like this to list how the paths relate to different vendor/product ID pairs:

for X in /sys/bus/usb/devices/*; do 
    echo "$X"
    cat "$X/idVendor" 2>/dev/null 
    cat "$X/idProduct" 2>/dev/null
    echo
done

Answer 3

This will reset all of USB1/2/3 attached ports[1]:

for i in /sys/bus/pci/drivers/[uoex]hci_hcd/*:*; do
  [ -e "$i" ] || continue
  echo "${i##*/}" > "${i%/*}/unbind"
  echo "${i##*/}" > "${i%/*}/bind"
done

I believe this will solve your problem. If you do not want to reset all of the USB endpoints, you can use appropriate device ID from /sys/bus/pci/drivers/ehci_hcd

---

Notes: [1]: the *hci_hcd kernel drivers typically control the USB ports. ohci_hcd and uhci_hcd are for USB1.1 ports, ehci_hcd is for USB2 ports and xhci_hcd is for USB3 ports. (see https://en.wikipedia.org/wiki/Host_controller_interface_(USB,_Firewire))

Answer 4

Since the APT package usbutils provides the usbreset binary you can just reset the USB device by:

usbreset ${USB_ID}

e.g.
usbreset 0d8c:0102

Answer 5

I've created a Python script that simplifies the whole process based on answers here.

Save the script below as reset_usb.py or clone this repo.

Usage:

python reset_usb.py help  # Show this help
sudo python reset_usb.py list  # List all USB devices
sudo python reset_usb.py path /dev/bus/usb/XXX/YYY  # Reset USB device using path /dev/bus/usb/XXX/YYY
sudo python reset_usb.py search "search terms"  # Search for USB device using the search terms within the search string returned by list and reset matching device
sudo python reset_usb.py listpci  # List all PCI USB devices
sudo python reset_usb.py pathpci /sys/bus/pci/drivers/.../XXXX:XX:XX.X  # Reset PCI USB device using path /sys/bus/pci/drivers/.../XXXX:XX:XX.X
sudo python reset_usb.py searchpci "search terms"  # Search for PCI USB device using the search terms within the search string returned by listpci and reset matching device

Script:

#!/usr/bin/env python
import os
import sys
from subprocess import Popen, PIPE
import fcntl

instructions = '''
Usage: python reset_usb.py help : Show this help
       sudo python reset_usb.py list : List all USB devices
       sudo python reset_usb.py path /dev/bus/usb/XXX/YYY : Reset USB device using path /dev/bus/usb/XXX/YYY
       sudo python reset_usb.py search "search terms" : Search for USB device using the search terms within the search string returned by list and reset matching device
       sudo python reset_usb.py listpci : List all PCI USB devices
       sudo python reset_usb.py pathpci /sys/bus/pci/drivers/.../XXXX:XX:XX.X : Reset PCI USB device using path
       sudo python reset_usb.py searchpci "search terms" : Search for PCI USB device using the search terms within the search string returned by listpci and reset matching device       
       '''


if len(sys.argv) < 2:
    print(instructions)
    sys.exit(0)

option = sys.argv[1].lower()
if 'help' in option:
    print(instructions)
    sys.exit(0)


def create_pci_list():
    pci_usb_list = list()
    try:
        lspci_out = Popen('lspci -Dvmm', shell=True, bufsize=64, stdin=PIPE, stdout=PIPE, close_fds=True).stdout.read().strip().decode('utf-8')
        pci_devices = lspci_out.split('%s%s' % (os.linesep, os.linesep))
        for pci_device in pci_devices:
            device_dict = dict()
            categories = pci_device.split(os.linesep)
            for category in categories:
                key, value = category.split('\t')
                device_dict[key[:-1]] = value.strip()
            if 'USB' not in device_dict['Class']:
                continue
            for root, dirs, files in os.walk('/sys/bus/pci/drivers/'):
                slot = device_dict['Slot']
                if slot in dirs:
                    device_dict['path'] = os.path.join(root, slot)
                    break
            pci_usb_list.append(device_dict)
    except Exception as ex:
        print('Failed to list pci devices! Error: %s' % ex)
        sys.exit(-1)
    return pci_usb_list


def create_usb_list():
    device_list = list()
    try:
        lsusb_out = Popen('lsusb -v', shell=True, bufsize=64, stdin=PIPE, stdout=PIPE, close_fds=True).stdout.read().strip().decode('utf-8')
        usb_devices = lsusb_out.split('%s%s' % (os.linesep, os.linesep))
        for device_categories in usb_devices:
            if not device_categories:
                continue
            categories = device_categories.split(os.linesep)
            device_stuff = categories[0].strip().split()
            bus = device_stuff[1]
            device = device_stuff[3][:-1]
            device_dict = {'bus': bus, 'device': device}
            device_info = ' '.join(device_stuff[6:])
            device_dict['description'] = device_info
            for category in categories:
                if not category:
                    continue
                categoryinfo = category.strip().split()
                if categoryinfo[0] == 'iManufacturer':
                    manufacturer_info = ' '.join(categoryinfo[2:])
                    device_dict['manufacturer'] = manufacturer_info
                if categoryinfo[0] == 'iProduct':
                    device_info = ' '.join(categoryinfo[2:])
                    device_dict['device'] = device_info
            path = '/dev/bus/usb/%s/%s' % (bus, device)
            device_dict['path'] = path

            device_list.append(device_dict)
    except Exception as ex:
        print('Failed to list usb devices! Error: %s' % ex)
        sys.exit(-1)
    return device_list


if 'listpci' in option:
    pci_usb_list = create_pci_list()
    for device in pci_usb_list:
        print('path=%s' % device['path'])
        print('    manufacturer=%s' % device['SVendor'])
        print('    device=%s' % device['SDevice'])
        print('    search string=%s %s' % (device['SVendor'], device['SDevice']))
    sys.exit(0)

if 'list' in option:
    usb_list = create_usb_list()
    for device in usb_list:
        print('path=%s' % device['path'])
        print('    description=%s' % device['description'])
        print('    manufacturer=%s' % device['manufacturer'])
        print('    device=%s' % device['device'])
        print('    search string=%s %s %s' % (device['description'], device['manufacturer'], device['device']))
    sys.exit(0)

if len(sys.argv) < 3:
    print(instructions)
    sys.exit(0)

option2 = sys.argv[2]

print('Resetting device: %s' % option2)


# echo -n "0000:39:00.0" | tee /sys/bus/pci/drivers/xhci_hcd/unbind;echo -n "0000:39:00.0" | tee /sys/bus/pci/drivers/xhci_hcd/bind
def reset_pci_usb_device(dev_path):
    folder, slot = os.path.split(dev_path)
    try:
        fp = open(os.path.join(folder, 'unbind'), 'wt')
        fp.write(slot)
        fp.close()
        fp = open(os.path.join(folder, 'bind'), 'wt')
        fp.write(slot)
        fp.close()
        print('Successfully reset %s' % dev_path)
        sys.exit(0)
    except Exception as ex:
        print('Failed to reset device! Error: %s' % ex)
        sys.exit(-1)


if 'pathpci' in option:
    reset_pci_usb_device(option2)


if 'searchpci' in option:
    pci_usb_list = create_pci_list()
    for device in pci_usb_list:
        text = '%s %s' % (device['SVendor'], device['SDevice'])
        if option2 in text:
            reset_pci_usb_device(device['path'])
    print('Failed to find device!')
    sys.exit(-1)


def reset_usb_device(dev_path):
    USBDEVFS_RESET = 21780
    try:
        f = open(dev_path, 'w', os.O_WRONLY)
        fcntl.ioctl(f, USBDEVFS_RESET, 0)
        print('Successfully reset %s' % dev_path)
        sys.exit(0)
    except Exception as ex:
        print('Failed to reset device! Error: %s' % ex)
        sys.exit(-1)


if 'path' in option:
    reset_usb_device(option2)


if 'search' in option:
    usb_list = create_usb_list()
    for device in usb_list:
        text = '%s %s %s' % (device['description'], device['manufacturer'], device['device'])
        if option2 in text:
            reset_usb_device(device['path'])
    print('Failed to find device!')
    sys.exit(-1)

Answer 6

I needed to automate this in a python script, so I adapted LiLo's extremely helpful answer to the following:

#!/usr/bin/env python
import os
import sys
from subprocess import Popen, PIPE
import fcntl
driver = sys.argv[-1]
print "resetting driver:", driver
USBDEVFS_RESET= 21780

try:
    lsusb_out = Popen("lsusb | grep -i %s"%driver, shell=True, bufsize=64, stdin=PIPE, stdout=PIPE, close_fds=True).stdout.read().strip().split()
    bus = lsusb_out[1]
    device = lsusb_out[3][:-1]
    f = open("/dev/bus/usb/%s/%s"%(bus, device), 'w', os.O_WRONLY)
    fcntl.ioctl(f, USBDEVFS_RESET, 0)
except Exception, msg:
    print "failed to reset device:", msg

In my case it was the cp210x driver (which I could tell from lsmod | grep usbserial), so you could save the above snippet as reset_usb.py and then do this:

sudo python reset_usb.py cp210x

This might also be helpful if you don't already have a c compiler setup on your system, but you do have python.

Answer 7

Quickest way to reset will be to reset the USB controller itself. Doing so will enforce udev to unregister the device on disconnection, and register is back once you enable it.

echo -n "0000:00:1a.0" | tee /sys/bus/pci/drivers/ehci_hcd/unbind
echo -n "0000:00:1d.0" | tee /sys/bus/pci/drivers/ehci_hcd/unbind
echo -n "0000:00:1a.0" | tee /sys/bus/pci/drivers/ehci_hcd/bind
echo -n "0000:00:1d.0" | tee /sys/bus/pci/drivers/ehci_hcd/bind

This should work for most PC environment. However, if you are using some custom hardware you can simply iterate through the device names. With this method you don't need to find out the device name by lsusb. You can incorporate in a automated script as well.

Answer 8

I'm using kind of sledgehammer by reloading the modules. This is my usb_reset.sh script:

#!/bin/bash

# USB drivers
rmmod xhci_pci
rmmod ehci_pci

# uncomment if you have firewire
#rmmod ohci_pci

modprobe xhci_pci
modprobe ehci_pci

# uncomment if you have firewire
#modprobe ohci_pci

And this is my systemd service file /usr/lib/systemd/system/usbreset.service which runs usb_reset.sh after my diplay manager has started:

[Unit]
Description=usbreset Service
After=gdm.service
Wants=gdm.service

[Service]
Type=oneshot
ExecStart=/path/to/usb_reset.sh

Answer 9

As the special case of the question is a communication problem of gphoto2 with a camera on USB, there is an option in gphoto2 to reset its USB connection:

gphoto2 --reset

Maybe this option didn't exist in 2010 when the question was asked.

Answer 10

I made a python script which will reset a particular USB device based on the device number. You can find out the device number from command lsusb.

for example:

$ lsusb

Bus 002 Device 004: ID 046d:c312 Logitech, Inc. DeLuxe 250 Keyboard

In this string 004 is the device number

import os
import argparse
import subprocess

path='/sys/bus/usb/devices/'

def runbash(cmd):
    p = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE)
    out = p.stdout.read().strip()
    return out

def reset_device(dev_num):
    sub_dirs = []
    for root, dirs, files in os.walk(path):
            for name in dirs:
                    sub_dirs.append(os.path.join(root, name))

    dev_found = 0
    for sub_dir in sub_dirs:
            if True == os.path.isfile(sub_dir+'/devnum'):
                    fd = open(sub_dir+'/devnum','r')
                    line = fd.readline()
                    if int(dev_num) == int(line):
                            print ('Your device is at: '+sub_dir)
                            dev_found = 1
                            break

                    fd.close()

    if dev_found == 1:
            reset_file = sub_dir+'/authorized'
            runbash('echo 0 > '+reset_file) 
            runbash('echo 1 > '+reset_file) 
            print ('Device reset successful')

    else:
            print ("No such device")

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('-d', '--devnum', dest='devnum')
    args = parser.parse_args()

    if args.devnum is None:
            print('Usage:usb_reset.py -d <device_number> \nThe device    number can be obtained from lsusb command result')
            return

    reset_device(args.devnum)

if __name__=='__main__':
    main()

Answer 11

Here is script that will only reset a matching product/vendor ID.

#!/bin/bash

set -euo pipefail
IFS=$'\n\t'

VENDOR="045e"
PRODUCT="0719"

for DIR in $(find /sys/bus/usb/devices/ -maxdepth 1 -type l); do
  if [[ -f $DIR/idVendor && -f $DIR/idProduct &&
        $(cat $DIR/idVendor) == $VENDOR && $(cat $DIR/idProduct) == $PRODUCT ]]; then
    echo 0 > $DIR/authorized
    sleep 0.5
    echo 1 > $DIR/authorized
  fi
done

Answer 12

Try this, it's a software unplug (Eject).

Sometimes doesn't work simply unbind device for some devices.

Example:

I want to remove or eject my "Genius NetScroll 120".

Then i first Check my attached usb device

$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 003: ID 03f0:231d Hewlett-Packard 
Bus 001 Device 004: ID 138a:0007 Validity Sensors, Inc. VFS451 Fingerprint Reader
Bus 001 Device 005: ID 04f2:b163 Chicony Electronics Co., Ltd 
Bus 002 Device 009: ID 0458:003a KYE Systems Corp. (Mouse Systems) NetScroll+ Mini Traveler / Genius NetScroll 120  **<----This my Mouse! XDDD**

Ok, i found my mouse, it's has a Bus 002, Device 009, idVendor 0458 and idProduct 003a, so this is a reference device info about the mouse.

This is important, the Bus number is the begin name path to device and i will check the product Id and Vendor to ensure the correct device to remove.

$ ls /sys/bus/usb/drivers/usb/
1-1/    1-1.1/  1-1.3/  1-1.5/  2-1/    2-1.3/  bind    uevent  unbind  usb1/   usb2/

Pay atention on the folders, check the begining with folder number 2, i will check this one because my Bus is 002, and one by one i have check each folder containing the correct idVendor and idProduct about my mouse info.

In this case, i will retrieve the info with this command:

cat /sys/bus/usb/drivers/usb/2-1.3/idVendor
0458
cat /sys/bus/usb/drivers/usb/2-1.3/idProduct
003a

Ok, the path /sys/bus/usb/drivers/usb/2-1.3/ match with my info mouse! XDDD.

It's time to remove the device!

su -c "echo 1 > /sys/bus/usb/drivers/usb/2-1.3/remove"

Plug again the usb device and it's work again!

Answer 13

Did somebody order a sledgehammer? This is pieced together from various other answers here.

#!/bin/bash

# Root required
if (( UID )); then
        exec sudo "$0" "$@"
fi

cd /sys/bus/pci/drivers

function reinit {(
        local d="$1"
        test -e "$d" || return

        rmmod "$d"

        cd "$d"

        for i in $(ls | grep :); do
                echo "$i" > unbind
        done

        sleep 1

        for i in $(ls | grep :); do
                echo "$i" > bind
        done

        modprobe "$d"

)}

for d in ?hci_???; do
        echo " - $d"
        reinit "$d"
done

Answer 14

Sometimes I want to perform this operation on a particular device, as identified by VID (vendor id) and PID (product id). This is a script I've found useful for this purpose, that uses the nifty libusb library.

First run:

sudo apt-get install libusb-dev

Then, this c++ file's resetDeviceConnection should perform this task, of resetting a device connection as identified by vid and pid.

#include <libusb-1.0/libusb.h>

int resetDeviceConnection(UINT_16 vid, UINT_16 pid){
    /*Open libusb*/
    int resetStatus = 0;
    libusb_context * context;
    libusb_init(&context);

    libusb_device_handle * dev_handle = libusb_open_device_with_vid_pid(context,vid,pid);
    if (dev_handle == NULL){
      printf("usb resetting unsuccessful! No matching device found, or error encountered!\n");
      resetStatus = 1;
    }
    else{
      /*reset the device, if one was found*/
      resetStatus = libusb_reset_device(dev_handle);
    }
    /*exit libusb*/
    libusb_exit(context);
    return resetStatus;
}

(stolen from my personal TIL catalog: https://github.com/Marviel/TIL/blob/master/unix_tools/Reset_specific_USB_Device.md)

Answer 15

i made a simple bash script for reset particular USB device.

#!/bin/bash
#type lsusb to find "vendor" and "product" ID in terminal
set -euo pipefail
IFS=$'\n\t'

#edit the below two lines of vendor and product values using lsusb result
dev=$(lsusb -t | grep usbdevicename | grep 'If 1' | cut -d' ' -f13|cut -d"," -f1)
#VENDOR=05a3
#PRODUCT=9230
VENDOR=$(lsusb -s $dev | cut -d' ' -f6 | cut -d: -f1)
PRODUCT=$(lsusb -s $dev | cut -d' ' -f6 | cut -d: -f2)

for DIR in $(find /sys/bus/usb/devices/ -maxdepth 1 -type l); do
  if [[ -f $DIR/idVendor && -f $DIR/idProduct &&
        $(cat $DIR/idVendor) == $VENDOR && $(cat $DIR/idProduct) == $PRODUCT ]]; then
    echo 0 > $DIR/authorized
    sleep 0.5
    echo 1 > $DIR/authorized
  fi
done

Answer 16

If you know your device name, this python script will work:

#!/usr/bin/python
"""
USB Reset

Call as "usbreset.py <device_file_path>"

With device_file_path like "/dev/bus/usb/bus_number/device_number"
"""
import fcntl, sys, os

USBDEVFS_RESET = ord('U') << (4*2) | 20

def main():
    fd = os.open(sys.argv[1], os.O_WRONLY)
    if fd < 0: sys.exit(1)
    fcntl.ioctl(fd, USBDEVFS_RESET, 0)
    os.close(fd)
    sys.exit(0)
# end main

if __name__ == '__main__':
    main()

Answer 17

This is a very elegant and yet ugly way of doing it. I ran a shell line in cpp which uses python to reset the usb.

1. install the python usb library: sudo pip3 install pyusb

2. get the ID of the vendor and product so you can use it in the code: lsusb -v

3. copy-paste the follwing code but remember to replace <vendor_id> and <product_id> with the vendor ID and product ID that you found in the previous step:

#include <iostream>

int main()
{
    int res = system("echo \"from usb.core import find as finddev; dev=finddev(idVendor=<vendor_id>,idProduct=<product_id>); dev.reset()\" | python3");

    return res;
}

Answer 18

Pure bash script for finding which USB device and driver provide a given network interface, and then resetting the device by unbinding and rebinding that driver:

#!/usr/bin/env bash
DEV=${1-eth1}

DRIVER=$(readlink -f /sys/class/net/$DEV/device/driver) # E.g. /sys/bus/usb/drivers/ax88179_178a
DEVICE=$(find $DRIVER -name '*:*' -printf %f) # E.g. 4-2:1.0

echo $DEVICE > $DRIVER/unbind
echo $DEVICE > $DRIVER/bind

Answer 19

So far I came to the conclusion that you cannot control the power of a USB port. The 5V USB is always provided, and it's up to the device to use it or not. You can check this with a 5V fan or light.

So there's no perfect way to make a USB reset. Nevertheless,

I've tried various methods found on stackoverflow, stackexchange etc, (disconnect/reconnect/bind/unbind/reset signal). Best so far are bind/unbind as it forces a cold restart of the device (but no power cycle).

I came up with a solution to reset USB devices, ports and controllers in a python script, which supports all of the above methods. You can find the script at my Github page

Install with pip install usb_resetter

Usage:

usb_resetter --help

#Example:
usb_resetter -d 8086:1001 --reset-hub

The script uses among others the following solution to reset USB hubs/controllers:

Unbindind a USB port / controller works best via:

echo "myhub" > "/sys/bus/usb/drivers/usb/unbind"
echo "myhub" > "/sys/bus/usb/drivers/usb/bind"

Where myhub is found in /sys/bus/usb/devices/*

Or litteral controllers:

echo "mycontroller" > "/sys/bus/pci/drivers/unbind"
echo "mycontroller" > "/sys/bus/pci/drivers/bind"

Where mycontroller is found in /sys/bus/pci/drivers/[uoex]hci_hcd/*:*

Answer 20

Perhaps this works for a camera, too:

Following revived a starved USB 3.0 HDD on a 3.4.42 (kernel.org) Linux on my side. dmesg told, that it was timing out commands after 360s (sorry, I cannot copy the syslog here, not connected networks) and the drive hung completely. Processes accessing the device were blocked in the kernel, unkillable. NFS hung, ZFS hung, dd hung.

After doing this, everything worked again. dmesg told just a single line about the USB device found.

I really have no idea what following does in detail. But it worked.

The following example output is from Debian Squeeze with 2.6.32-5-686 kernel, so I think it works for 2.6 and above:

$ ls -al /dev/sdb
brw-rw---T 1 root floppy 8, 16 Jun  3 20:24 /dev/sdb

$ ls -al /sys/dev/block/8:16/device/rescan
--w------- 1 root root 4096 Jun  6 01:46 /sys/dev/block/8:16/device/rescan

$ echo 1 > /sys/dev/block/8:16/device/rescan

If this does not work, perhaps somebody else can figure out how to send a real reset to a device.