This is a small modification on CHIP computer that allows to power off the USB port.
As seen in the schematics, U15 supplies power to the USB port. U15 is enabled by a pull-up resistor (R86) on pin 4.
By soldering a wire on U15 Pin4 and connecting it to a GPIO port like XIO_P0, USB power can be controlled by software.
fordsfords has a nice GPIO control library for bash on Github
git clone https://github.com/fordsfords/gpio_sh.git cd gpio_sh source gpio.sh
Set port direction
gpio_export XIO_P0 gpio_direction XIO_P0 out
and then use:
gpio_output XIO_P0 0
to power off USB
gpio_output XIO_P0 1
to bring power back.