USB : disable and reenable device on linux

Question

I have an USB device that sometimes hangs. Since it is really a pain to unplug/plug it (cables under desk, behind things...), is there a way to virtually unplug/plug the device ? For example by shutting down its power then bring it back again ?

Thanks

Answer 1

Try with the USBDEVFS_RESET ioctl.

If your system doesn't come with a usbreset utility as part of usbutils, you can compile the one from https://github.com/gregkh/usbutils/blob/master/usbreset.c with just cc usbreset.c -o usbreset.

On some devices (like my router) you'll have to reset the hub it's connected to instead of the device for it to have effect.

# ./usbreset
Usage:
  usbreset PPPP:VVVV - reset by product and vendor id
  usbreset BBB/DDD   - reset by bus and device number
  usbreset "Product" - reset by product name

Devices:
  Number 001/004  ID 062a:4101  2.4G Keyboard Mouse
  Number 001/006  ID 03f0:e111  DeskJet 2130 series
  Number 001/002  ID 05e3:0608  USB2.0 Hub
  Number 001/005  ID 248a:8514  Wireless Receiver
  Number 001/003  ID 05e3:0608  USB2.0 Hub
$ ./a.out 062a:4101

Answer 2

The accepted USBDEVFS_RESET solution is not as good as replugging (based on the kernel messages). Better use the "port" interface, e.g.:

echo 1 > /sys/bus/usb/devices/3-2.1/port/disable

See more on this on my other answer.