I'm using a special USB device that is providing an interface to a field bus system. The device driver is creating a virtual network interface. In my software I connect to this virtual network and can read/write the field bus. This is working well as long as I do not reboot the armstone (warm boot e.g. by calling reboot in console). After reboot this USB device is not available anymore and cannot be seen when calling lsusb. When I power off/on the armstone everything is working well again. I'm also using other USB devices (e.g. capacitive USB Touch). These other devices are working after warm boot. On other platforms/kernel versions the field bus USB device was working after warm boot also.