Re: [lwip-devel] Missing initialization somewhere?

[Kieran Mansley]

On Wed, 2011-10-12 at 18:22 -0700, Sergey Kubushyn wrote:
> The problem is it does not happen on every reset. Something like half
> of
> them result in a non-working system. On a connection attempt MCU sends
> ARP
> for the remote on the first SYN packet received, gets a response and
> then
> network is dead. No echo replies, no ARP requests/replies, nothing. It
> hangs
> on the very first SYN so tcp_accept() callback is not called etc. 

This doesn't sounds familiar, so I don't think anyone else has already
found and fixed your problem.   Do you have ARP_QUEUING turned on?  I
was just wondering if that could explain the difference between TCP and
ICMP, as without it you would be relying on the TCP retransmission
timers, whereas with ping another ICMP packet would come along a second
later.  I would certainly investigate whether the TCP timers are being
called correctly, although that doesn't explain why the stack wouldn't
respond to other packets.  For that to happen it sounds like a race
condition that has caused a list in lwIP to be corrupted and so
something that iterates the list to be in an infinite loop.  This is
usually because of not interfacing the application or driver to lwIP
correctly, resulting in concurrent access from more than one context.

Kieran