usb_for_each_dev (9)

int usb_for_each_dev(void * data, int (*fn) (struct usb_device *, void *));

data

data pointer that will be handed to the callback function

fn

callback function to be called for each USB device

Iterate over all USB devices and call fn for each, passing it data. If it returns anything other than 0, we break the iteration prematurely and return that value.