Take a look here:

viewtopic.php?f=66&t=122760&p=827183#p827183

Depending on your kernel, one of those solutions might be what you're looking for.

Found the answer elsewhere; looks like the device ID is different and has moved. This worked: echo 0 > /sys/devices/platform/soc/3f980000.usb/buspower sleep 2 echo 1 > /sys/devices/platform/soc/3f980000.usb/buspower sleep 3 (specifics of sleep durations not finely tuned, so this may be optimizable f...

On an RPi2 Model B with Wheezy installed, I was able to reset the USB stack using: sleep 0.1 echo 0 > /sys/devices/platform/bcm2708_usb/buspower sleep 1 echo 1 > /sys/devices/platform/bcm2708_usb/buspower sleep 2 However, on a Jessie install, /sys/devices/platform/bcm2708_usb/ does not exist. Is the...