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.

  • Which version of Ubuntu are you using? – User Aug 1 '10 at 20:15
  • i tried both solutions by Li Lo and ssokolow, all i get is permission denied, nomatter if i use the usbreset code or the command line "echo 0 > ..." i use sudo, also my usb devices are owned by root but i can use them without admin rights(cameras..) – user290672 Jun 8 '14 at 16:40
  • If you are getting read errors, you might have some data corruption. If your camera uses an external memory card (such as MicroSD), it might be wise to connect it to the computer and run fsck. – TSJNachos117 Jun 8 '14 at 18:47

16 Answers 16

up vote 98 down vote accepted

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");

    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:

  • I got errors like this: ./usbreset: command not found Dan 11.04 Natty – user24895 Sep 13 '11 at 4:33
  • Thank you so much! This will help me get a lot more life out of my dying Intellimouse. – Randall Ma Dec 15 '13 at 0:55
  • 3
    This works with ubuntu 13.10. The device ID can vary. TO get it for the mouse I have wrapped above code in few shell commands echo $(lsusb | grep Mouse) mouse=$( lsusb | grep Mouse | perl -nE "/\D+(\d+)\D+(\d+).+/; print qq(\$1/\$2)") sudo /path/to/c-program/usbreset /dev/bus/usb/$mouse – knb Dec 22 '13 at 11:04
  • 1
    If anyone reading this have a (usb) mouse freeze after logging in on Ubuntu 16.04 (with dmesg filled by "input irq status -75") , i can confirm that this is the only solution that worked for me. Thank you – Agustin Baez May 2 '16 at 12:31
  • 1
    @ Aquarius, I also get the same error "Error in ioctl: Is a directory". Is it resolved ? – ransh Feb 12 '17 at 13:21

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
  • sh: 1: cannot create /sys/bus/usb/devices/1-3.1:1.0/authorized: Directory nonexistent – Nicolas Marchildon May 31 '12 at 3:22
  • It looks like they've changed the layout of the usbfs filesystem. I'll try to figure out what the new way of doing things is on Ubuntu once I'm not so sleepy. – ssokolow Jun 2 '12 at 15:46
  • 6
    Thank you worked great! Maybe you should also mention to perform a echo 1 > /sys/bus/usb/devices/whatever/authorized inside a script to re-enable the device as soon as it has been disabled. I did it on both my mouse and usb keyboard and I ended up with a completely deaf system :) – Avio Apr 28 '13 at 8:43
  • Last time I used it, something in the system would reset it to 1 a second or two later without me having to do it manually. – ssokolow Apr 29 '13 at 20:33
  • 1
    A note for anyone who tries to switch to the | sudo tee ... approach to privileged /sys writes: That breaks badly if you don't already have your sudo credentials cached. sudo sh -c "..." works as expected when sudo needs to prompt for a password. – ssokolow Jun 5 '16 at 10:40

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"

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,_Firewire))

  • do you believe it may work to wakeup an usb storage? – Aquarius Power Jun 30 '14 at 5:53
  • 2
    Although I've received the following message: ls: cannot access /sys/bus/pci/drivers/ehci_hcd/: No such file or directory this has resolved the issue, the mouse has started working immediately. +1 – Attila Fulop Oct 10 '14 at 6:16
  • is it possible to add a check to skip mounted USB mass storage devices? – eadmaster Nov 1 '15 at 10:32
  • 2
    @Otheus OHCI and UHCI are the USB 1.1 host standards, EHCI is the USB 2.0 host standard, and XHCI is the USB 3.0 host standard. – ssokolow Jul 20 '16 at 19:02
  • 1
    This is a beautiful solution. However, on some later Kernels and other *nix distributions, you will find that you need to substitute *hci_hcd with *hci-pci, as the hci_hcd driver is already compiled into the Kernel. – not2qubit Mar 1 '17 at 17:14

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

    lsusb_out = Popen("lsusb | grep -i %s"%driver, shell=True, bufsize=64, stdin=PIPE, stdout=PIPE, close_fds=True)
    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 and then do this:

sudo python cp210x

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

  • worked for me on a Raspberry – webo80 Jun 23 '16 at 14:36
  • 1
    A few more words on your solution please. For example, something about the constant USBDEVFS_RESET. Is it always the same for all systems? – not2qubit Feb 28 '17 at 7:25
  • @not2qubit USBDEVFS_RESET is the same for all systems. For MIPS it is 536892692. – yegorich Apr 21 '17 at 9:09
  • Newer versions of lsusb seem to need the -t argument (tree mode) to show the driver info that this script is expecting, but the script then needs some updates to parse the different output lines this generates – Cheetah Oct 19 '17 at 18:56
  • See my answer here for a much improved version of this script. – mcarans Dec 21 '17 at 10:30

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


# 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 after my diplay manager has started:

Description=usbreset Service

  • Using the listpci option of my script here: will help identify which USB module to reload (eg. xhci_pci, ehci_pci). – mcarans Jan 24 at 15:14
  • Unfortunately on my system these kernel modules are not separate form the kernel, so this won't work: rmmod: ERROR: Module xhci_pci is builtin. – unfa Jun 28 at 13:00

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.

  • 1
    You need to run these commands as root/sudo, and it will not work on all systems (on some, you'll need to replace ehci_hcd with ehci-pci. More info on this solution (perhaps where it came from?):… – Lambart Nov 5 '15 at 17:43

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.

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


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


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

            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(' -d <device_number> \nThe device    number can be obtained from lsusb command result')


if __name__=='__main__':

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


set -euo pipefail


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
  • 1
    I found your script is useful. But what should I do if the $DIR disappears and device is not visible? – Eugen Konkov Oct 13 '17 at 7:36

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

Save the script below as or clone this repo:


python help : Show this help

sudo python list : List all USB devices

sudo python path /dev/bus/usb/XXX/YYY : Reset USB device using path /dev/bus/usb/XXX/YYY

sudo python search "search terms" : Search for USB device using the search terms within the search string returned by list and reset matching device

sudo python listpci : List all PCI USB devices

sudo python 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 searchpci "search terms" : Search for PCI USB device using the search terms within the search string returned by listpci and reset matching device

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

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

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

def create_pci_list():
    pci_usb_list = list()
        lspci_out = Popen('lspci -Dvmm', shell=True, bufsize=64, stdin=PIPE, stdout=PIPE, close_fds=True)'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']:
            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)
    except Exception as ex:
        print('Failed to list pci devices! Error: %s' % ex)
    return pci_usb_list

def create_usb_list():
    device_list = list()
        lsusb_out = Popen('lsusb -v', shell=True, bufsize=64, stdin=PIPE, stdout=PIPE, close_fds=True)'utf-8')
        usb_devices = lsusb_out.split('%s%s' % (os.linesep, os.linesep))
        for device_categories in usb_devices:
            if not device_categories:
            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:
                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

    except Exception as ex:
        print('Failed to list usb devices! Error: %s' % ex)
    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']))

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']))

if len(sys.argv) < 3:

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)
        fp = open(os.path.join(folder, 'unbind'), 'wt')
        fp = open(os.path.join(folder, 'bind'), 'wt')
        print('Successfully reset %s' % dev_path)
    except Exception as ex:
        print('Failed to reset device! Error: %s' % ex)

if 'pathpci' in option:

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:
    print('Failed to find device!')

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

if 'path' in option:

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:
    print('Failed to find device!')

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


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

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

        sleep 1

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

        modprobe "$d"


for d in ?hci_???; do
        echo " - $d"
        reinit "$d"
  • Mark, have you found that the unbinding is really necessary or is it here just to be on the safe side? – ndemou Nov 10 '16 at 14:27
  • This is a sledgehammer, it probably does a lot of unnecessary things – Mark K Cowan Nov 10 '16 at 14:37
  • @MarkKCowan , How do you use it? What are the command arguments needed/expected? – not2qubit Feb 28 '17 at 7:15
  • @not2qubit: No command-line arguments required. The $@ in the sudo proxy is just a force of habbit, having it prevents bugs if I later decide to add arguments (and forget to update the sudo proxy). – Mark K Cowan Nov 21 '17 at 14:54
  • 1
    @MarkKCowan Doh! Sorry mate! Oh yes of curse! I should not be commenting on this site while sleepy. Upvoted! – not2qubit Nov 21 '17 at 16:29

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_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;
      /*reset the device, if one was found*/
      resetStatus = libusb_reset_device(dev_handle);
    /*exit libusb*/
    return resetStatus;

(stolen from my personal TIL catalog:

  • 3
    Please can you show how this script is run. – George Udosen Dec 29 '16 at 14:28
  • Sure thing, let me update. – Marviel Dec 29 '16 at 20:31
  • 1
    @Marviel, we're still waiting for an update... – not2qubit Feb 28 '17 at 7:18
  • needs downvote as useless – Eugen Konkov Oct 13 '17 at 7:36

Perhaps this works for a camera, too:

Following revived a starved USB 3.0 HDD on a 3.4.42 ( 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.

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

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


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
cat /sys/bus/usb/drivers/usb/2-1.3/idProduct

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!

  • 9
    What if you can't plug it in again? (for example it's an internal sdcard reader) – aleb Jun 29 '14 at 20:57

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

USB Reset

Call as " <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 =[1], os.O_WRONLY)
    if fd < 0: sys.exit(1)
    fcntl.ioctl(fd, USBDEVFS_RESET, 0)
# end main

if __name__ == '__main__':

Maybe this guide can help you:

If you are pestered by the bug that doesn;t let you mount USB devices in Ubuntu Lucid Lynx, the issue is caused by the floppy module. Disable it with:

sudo modprobe -r floppy

After a reboot the module will likely reload.

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