[En-Nut-Discussion] Network Link state on at91_emac and others

[Harald Kipp]

Ole Reinhardt wrote:

> Sorry for me to insist on this... I checked it again and at least you
> are right in some way... At least I don't understand the real bahaviour
> right now...

Nice arguing, Ole: "I think the world is red, but I agree that you are 
right to some extend by saying it is blue, though I'm not able tell why 
it looks a bit blueish." :-)


> I will not getting tired to say sorry to not have tested enough before
> writing my mail :)

You want me fall asleep, don't you. ;-)


> No kidding! Keepalive seems to be the right way. But just implementing
> keepalive will not solve the problem either or at least just after a
> short time. I think if we enable keepalive we should also implement the
> link down detection.

There are two keepalive mechanisms I know of. One is system wide and 
very slow (typically a few minutes). The other one is enabled on a 
specific socket, is protocol specific and works within seconds.

As previously stated I'm aware, that some applications need to be 
informed about the link status. If we implement a callback registration, 
the application may decide about what to do in case of a link loss.

Harald