DC_TX_COALESCE
sc->dc_flags |= DC_TX_COALESCE | DC_TX_INTR_ALWAYS;
sc->dc_flags |= DC_TX_INTR_ALWAYS | DC_TX_COALESCE |
sc->dc_flags |= DC_TX_INTR_ALWAYS | DC_TX_COALESCE |
if (sc->dc_flags & DC_TX_COALESCE &&