ELX_LOOPBACK_HEADER_SZ
bpl->tus.f.bdeSize = ELX_LOOPBACK_HEADER_SZ;
memset(ctreq, 0, ELX_LOOPBACK_HEADER_SZ);
full_size = size + ELX_LOOPBACK_HEADER_SZ; /* plus the header */
ptr += ELX_LOOPBACK_HEADER_SZ;
memset(ctreq, 0, ELX_LOOPBACK_HEADER_SZ);
segment_offset = ELX_LOOPBACK_HEADER_SZ;
rx_databuf += ELX_LOOPBACK_HEADER_SZ;