How do I reset a USB device using a script?

Question

I have a USB GSM modem that does not alwasys work property (Huawei E367u-2) Sometimes it gets reset (USB device disconnect/reconnect in logs) and when it comes back up, it's has different ttyUSB numbers. Sometimes on boot, usb_modswitch seems to just not get fired. The computer is a Raspberry Pi running Raspbian.

I have a simple solution to this, every minute CRON runs the following script:

If WVDIAL is not running:
    Run WVDIAL

I want to change the script to be this:

If /dev/ttyUSB0 is not present:
    If DevicePresent(12d1:1446):
        ResetDevice(12d1:1446)
    ElseIs DevicePresemt(12d1:1506)
        ResetUSB(12d1:1506)
If WVDIAL is not running:
    Run WVDIAL

Obviously this is pseudo code, but I have the following lines that I need to string together but I can't figure out how:

This loads wvdial if it is not running:

#! /bin/sh 
# /etc/init.d/wvdial

### BEGIN INIT INFO
# Provides:          TheInternet
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Simple script to start a program at boot
# Description:       A simple script from www.stuffaboutcode.com which will start / stop a program a boot / shutdown.
### END INIT INFO

# If you want a command to always run, put it here

# Carry out specific functions when asked to by the system
case "$1" in
  start)
    echo "Starting GPRS Internet"
    # run application you want to start
    /sbin/start-stop-daemon --start --background --quiet --exec /usr/bin/wvdial internet
    ;;
  stop)
    echo "Stopping GPRS Internet"
    # kill application you want to stop
    /sbin/start-stop-daemon --stop --exec /usr/bin/wvdial 
    ;;
  *)
    echo "Usage: /etc/init.d/noip {start|stop}"
    exit 1
    ;;
esac

exit 0

This lets me find the /sys path to a certain device:

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

And this resets a USB device if you know the correct /sys path:

echo 0 > /sys/bus/usb/devices/1-1.2.1.1/authorized
echo 1 > /sys/bus/usb/devices/1-1.2.1.1/authorized

So, I need to string the last 2 sections and a test to /dev/ttyUSB0 into a section that goes under the "If you want a command to always run. put it here" section

UPDATE 1

usbreset, although functioning, does not do the job. Only echo 0 the 1 into authroized correctly simulates a device disconnect/reconnect.
This is what does the trick of booting the device or usb_modeswitch back into life. As such I've managed to cobble together this:

echo "Searching for $1"
devPath=`lsusb | grep $1 | sed -r 's/Bus ([0-9]{3}) Device ([0-9]{3}).*/bus\/usb\/\1\/\2/g;'`
echo "Found $1 @ $devPath"
echo "Searching for sysPath"
for sysPath in /sys/bus/usb/devices/*; do
    echo "$sysPath/uevent"
    devName=`cat "$sysPath/uevent" | grep $devPath`
    #echo devName=$devName
    if [ ! -z $devName ] 
    then
        break
    fi
done
if [ ! -z  $devName ] 
then
    echo "Found $1 @ $sysPath, Resetting"
    echo "echo 0 > $sysPath/authorized"
    echo 0 > $sysPath/authorized
    echo "echo 1 > $sysPath/authorized"
    echo 1 > $sysPath/authorized
else
    echo "Could not find $1"
fi

I think therefore all I have to do now is put this in the init.d script:

if ttyUSB0 not present
    if 12d1:1446 present
        /usr/sbin/resetdevicebyauthorized 12d1:1446
    else if 12d1:1506 present
        /usr/sbin/resetdevicebyauthorized 12d1:1506
    fi
fi

Answer 1

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 tow 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 2

You can reset USB bus via this C program. https://gist.github.com/x2q/5124616

Download C code from github

wget -c --no-check-certificate https://gist.githubusercontent.com/x2q/5124616/raw/3f6e5f144efab2bc8e9d02b95b8301e1e0eab669/usbreset.c -O usbreset.c

Compile C code as usbreset

cc usbreset.c -o usbreset

Give execute permission to program

chmod +x usbreset

List your USB devices via lsusb command

lsusb

You should see USB device entries in your output and check device you want to reset for.

Bus 002 Device 003: ID 0fe9:9010 DVICO

Run usbreset program with arguments

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

Answer 3

You can use pyusb to reset a device:

First install pyusb:

sudo pip install pyusb

Then create this script and run it:

#!/usr/bin/python
from usb.core import find as finddev
dev = finddev(idVendor=0x1234, idProduct=0x5678)
dev.reset()

Adapt the idVendor and idProduct to the device you want to reset (you can find the id via lsusb)

Answer 4

Thank you so much! This C-Code works just great. This is the simple shell script I did to identify the USB device

#!/bin/bash
USBNAME=webcam
LSUSB=$(lsusb | grep --ignore-case $USBNAME)
FOLD="/dev/bus/usb/"$(echo $LSUSB | cut --delimiter=' ' --fields='2')"/"$(echo $LSUSB | cut --delimiter=' ' --fields='4' | tr --delete ":")
echo $LSUSB
echo $FOLD
sudo ./usbreset $FOLD

Answer 5

Resetting my Huawei modem does not always work. Since I'm dialing in with a systemd service anyways, I added some lines that fully unpower all USB devices and reboots the raspberry after 5 minutes :-)

[Unit]
Description=GSM Internet
Requires=network.target
# If unable to start within 12hrs, unpower all USB and reboot
StartLimitIntervalSec=43200
StartLimitBurst=300
OnFailure=unpower-usb-reboot.service

[Service]
Type=forking
User=root
ExecStartPre=/bin/ls /dev/serial/by-id/usb-HUAWEI_Technology_HUAWEI_Mobile-if00-port0
ExecStart=/usr/bin/pon
RemainAfterExit=yes
ExecStop=/usr/bin/poff
Restart=always
RestartSec=120

[Install]
WantedBy=multi-user.target

[Unit]
Description=Unpowers all USB and reboots
[Service]
User=root
ExecStart=/bin/sh -c 'echo 0 > /sys/devices/platform/soc/20980000.usb/buspower; sleep 5m; shutdown -r now'