Full 32bit flowid from igb(4)

[Adrian Chadd]

Hi,

The main reason I didn't add it outside of RSS is that I didn't want
to impact the behaviour that was there before. Before, it wasn't using
the flowid - only the msix/queue id.

I read the intel datasheets about that particular field - I'm pretty
sure that by default we'll only see RSS hashed packets for IPv4/IPv6,
however non v4/v6 packets won't have a flowid. There are also cases of
the flow director or some hardware checksum config using the same
field as the flowid.

The /full/ solution would very carefully check the return status and
ensure what's in the flowid field is a flowid.

The "sometimes it may have a flowid, sometimes it won't" problem isn't
so bad with kernel RSS enabled - it'll just software hash it.


-adrian