def max_recv_data_size(self):
        """The maximum number of octets that can be received with the
        :meth:`exchange` method in the established operating mode.

        """
        with self.lock:
            if self.device is None:
                raise IOError(errno.ENODEV, os.strerror(errno.ENODEV))
            else:
                return self.device.get_max_recv_data_size(self.target)