Re: Resetting a USB port in Debian 10

[Tixy <tixy@yxit.co.uk>]

On Wed, 2022-05-18 at 17:22 -0500, Jason wrote:
> What is the best way to power cycle or reset a USB port?

The method I use, which I found described online is to unbind the
driver then re-bind it like...

   echo "$ID" >/sys/bus/usb/drivers/usb/unbind
   sleep 1
   echo "$ID" >/sys/bus/usb/drivers/usb/bind

To find the device ID my bash script scans the USB serial numbers
looking for the one I'm interested in...

   pushd /sys/bus/usb/drivers/usb >/dev/null
   for f in **/serial
   do
   	if [ "$(cat $f)" = MY_SERIAL_NUMBER ]; then
   		ID=${f%%/*}
   	fi
   done
   popd >/dev/null
   
   if [ "$ID" = "" ]; then
   	echo "Can't find device"
   	exit 1
   fi
   
There's no doubt better ways of doing the above, but it works for me.
(Looking at it now I'd get rid of the pushd/popd by using an extra
string splice operation and that use of ** probably needs something
doing to it to cope with spaces in paths)

-- 
Tixy