Man page 9 : usb_fill_int_urb

usb_fill_int_urb - macro to help initialize a interrupt urb

void usb_fill_int_urb(struct urb *  urb , struct usb_device *  dev , unsigned int  pipe , void *  transfer_buffer , int  buffer_length , usb_complete_t  complete_fn , void *  context , int  interval );

urb
    pointer to the urb to initialize.

dev
    pointer to the struct usb_device for this urb.

pipe
    the endpoint pipe

transfer_buffer
    pointer to the transfer buffer

buffer_length
    length of the transfer buffer

complete_fn
    pointer to the usb_complete_t function

context
    what to set the urb context to.

interval
    what to set the urb interval to, encoded like the endpoint descriptorAqs bInterval value.

Initializes a interrupt urb with the proper information needed to submit it to a device.

Note that High Speed and SuperSpeed interrupt endpoints use a logarithmic encoding of the endpoint interval, and express polling intervals in microframes (eight per millisecond) rather than in frames (one per millisecond).

Wireless USB also uses the logarithmic encoding, but specifies it in units of 128us instead of 125us. For Wireless USB devices, the interval is passed through to the host controller, rather than being translated into microframe units.