EFX_CKSUM_IPV4
flags |= EFX_CKSUM_IPV4;
(*flagsp) &= ~EFX_CKSUM_IPV4;
flags |= EFX_PKT_IPV4 | EFX_CKSUM_IPV4;
flags |= EFX_PKT_IPV4 | EFX_CKSUM_IPV4;
flags = EFX_PKT_IPV4 | EFX_CKSUM_IPV4;
csum_flags = (flags & EFX_CKSUM_IPV4) ?
~(EFX_CKSUM_IPV4 | EFX_CKSUM_TCPUDP);