HW_OWNER
PUTCTRL(ring, prod, len | OP_PACKET | HW_OWNER | EOP);
PUTCTRL(ring, cons, port->p_framesize | OP_PACKET | HW_OWNER);
if ((control & HW_OWNER) == 0) {
control &= ~HW_OWNER;
PUTCTRL(ring, prod, port->p_framesize | OP_PACKET | HW_OWNER);