int parport_wait_event (struct parport * port, signed long timeout);
This function waits for up to timeout jiffies for an interrupt to occur on a parallel port. If the port timeout is set to zero, it returns immediately.
If an interrupt occurs before the timeout period elapses, this function returns one immediately. If it times out, it returns a value greater than zero. An error code less than zero indicates an error (most likely a pending signal), and the calling code should finish what it's doing as soon as it can.