I am communicating with a USB device (LED screen) serially, via ttyUSB0 (visible in /dev/ttyUSB0).
However, it will not power off on shutdown or on suspend. Only via the terminal command 'reboot' or if I close the software communicating with the device.
Does anyone know why? I've tried manipulating the settings in /sys/bus/usb/devices/usb1/power with little effect.
System: Debian 8 (Jessie)