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Power OFF and ON USB device in linux (ubuntu)

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by

nsc
in

There are two methods of doing this. So first method is for kernels after 2.6.32, and second for older ones.

To view kernel version, simply enter:

> uname -r 
3.8.0-29-generic

 

find Your USB device, no mather what it is USB flash drive, Yubikey, USB disk drive:

> lsusb 
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
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 002 Device 005: ID 12d1:14db Huawei Technologies Co., Ltd. 
Bus 002 Device 006: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub

> lsusb -t
/:  Bus 02.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 1: Dev 5, If 0, Class=comm., Driver=cdc_ether, 480M
        |__ Port 1: Dev 5, If 1, Class=data, Driver=cdc_ether, 480M
        |__ Port 5: Dev 6, If 0, Class=hub, Driver=hub/4p, 480M
/:  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


Our target is:

Bus 002 Device 005: ID 12d1:14db Huawei Technologies Co., Ltd.

Which is located at 2-1.1 (tree part where device 5 is located)
First method (newer kernel)

To turn it off simply echo address:

echo '2-1.1' > /sys/bus/usb/drivers/usb/unbind

 

here is result from syslog:

Feb 20 12:03:27 vgsms6 kernel: [ 1734.993667] cdc_ether 2-1.1:1.0 eth2: unregister 'cdc_ether' usb-0000:00:1d.0-1.1, CDC Ethernet Device

Unfortunately this device was still visible in lsusb, so I turned off whole usb hub there (2-1), and voila, usb device gone.

To enable it, echo same address to “bind” part, for example:

echo '2-1.1' > /sys/bus/usb/drivers/usb/bind

 

Second method (older kernel)
You need to go to devices:

cd /sys/bus/usb/devices

 

Addressess will be listed similar:

/sys/bus/usb/devices# ls -alh
total 0
drwxr-xr-x 2 root root 0 Feb 20 11:34 .
drwxr-xr-x 4 root root 0 Feb 20 11:34 ..
lrwxrwxrwx 1 root root 0 Feb 20 11:34 1-0:1.0 -> ../../../devices/pci0000:00/0000:00:1a.0/usb1/1-0:1.0
lrwxrwxrwx 1 root root 0 Feb 20 11:34 1-1 -> ../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1
lrwxrwxrwx 1 root root 0 Feb 20 11:34 1-1:1.0 -> ../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1:1.0
lrwxrwxrwx 1 root root 0 Feb 20 11:34 2-0:1.0 -> ../../../devices/pci0000:00/0000:00:1d.0/usb2/2-0:1.0
lrwxrwxrwx 1 root root 0 Feb 20 11:34 2-1 -> ../../../devices/pci0000:00/0000:00:1d.0/usb2/2-1
lrwxrwxrwx 1 root root 0 Feb 20 12:34 2-1.1 -> ../../../devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1
lrwxrwxrwx 1 root root 0 Feb 20 12:34 2-1:1.0 -> ../../../devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1:1.0
lrwxrwxrwx 1 root root 0 Feb 20 12:34 2-1.1:1.0 -> ../../../devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.0
lrwxrwxrwx 1 root root 0 Feb 20 12:34 2-1.1:1.1 -> ../../../devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.1
lrwxrwxrwx 1 root root 0 Feb 20 12:34 2-1.5 -> ../../../devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5
lrwxrwxrwx 1 root root 0 Feb 20 12:34 2-1.5:1.0 -> ../../../devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5/2-1.5:1.0
lrwxrwxrwx 1 root root 0 Feb 20 11:34 usb1 -> ../../../devices/pci0000:00/0000:00:1a.0/usb1
lrwxrwxrwx 1 root root 0 Feb 20 11:34 usb2 -> ../../../devices/pci0000:00/0000:00:1d.0/usb2

 

So go to in our example 2-1.1/power (full path /sys/bus/usb/devices2-1.1/power)

cd /sys/bus/usb/devices2-1.1/power

 

to turn off device:

echo suspend > level

 

to turn on:

echo on > level

 

 

Comments

10 responses to “Power OFF and ON USB device in linux (ubuntu)”

  1. Anonymous Avatar
    Anonymous

    ~ $ sudo echo ‘1-1.2’ > /sys/bus/usb/drivers/usb/unbind
    -bash: /sys/bus/usb/drivers/usb/unbind: Permission denied

    Reply
  2. Nieko Avatar
    Nieko

    Thanks, finally got it working! :)

    Anonymous: your command executes “echo ‘1-1.2′” under sudo, and then tries to write that to /sys/bus/usb/drivers/usb/unbind as the normal user again. Try this: echo ‘1-1.2″ | sudo tee /sys/bus/usb/drivers/usb/unbind

    Reply
  3. Santos Avatar
    Santos

    You could also use a switchable USB hub.

    Something like this https://www.yepkit.com/products/ykush

    but it’s more expensive :)

    Reply
    1. nsc Avatar
      nsc

      Smart way of leaving a backlink.
      I encourage doing opensource projects :)

      Usually the budget depends on what are the requirements. For a simple “faulty” usb emergency device reset I would use my way (I wouldn’t expect something to break, would I?).

      But for day to day planned switch off/on I’d consider such device.
      Thanks for sharing Your product.
      That’s pretty useful thing, it should have more reliable switching capability and it’s more powerful than a server usb port.

      You should consider making a bigger hub, as it seems to be possible to use it as a powersource for usb devices (2Amps of current).
      For example external usb 2.5 hdd would already take 2 ports, leaving only one free.
      Or make an usb controlled power source switcher with relays, it would perfectly go as a combo with this usb hub device :)

      Reply
      1. Santos Avatar
        Santos

        Fully agree with you, the best approach depends of the requirements.

        Those are cool ideas for improving the product.

        Cheers

        Reply
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  6. Michael Avatar
    Michael

    I know the post is quite old, I just found it and trying to figure out how to make it work, this is the closest I got, but still not working (maybe due to my lack of deep Linux knowledge), I got an error “no such device”, is the error due to my device number in the echo command is wrong or I choose the wrong unbind?

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