RMNET_FLAGS_EGRESS_MAP_CKSUMV4
if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4) {
csum_type = RMNET_FLAGS_EGRESS_MAP_CKSUMV4;
case RMNET_FLAGS_EGRESS_MAP_CKSUMV4:
if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4)