RDT              2430 dev/pci/if_em.c 	E1000_WRITE_REG(&sc->hw, RDT, sc->num_rx_desc - 1);
RDT              2701 dev/pci/if_em.c 	E1000_WRITE_REG(&sc->hw, RDT, i);
RDT              1628 dev/pci/if_ixgb.c 	IXGB_WRITE_REG(&sc->hw, RDT, sc->num_rx_desc - 1);
RDT              1889 dev/pci/if_ixgb.c         IXGB_WRITE_REG(&sc->hw, RDT, next_to_use);