Re: [lwip-users] TCP Out-Of-Order/Retransmission/Connection closed issue

[Sergio R. Caprile]

David,
I hope you are also calling all other lwIP functions from the very same 
ISR you are calling tcp_tmr()... which you shouldn't be calling but 
sys_check_timeouts() instead; and as frequently as possible (like at the 
head of the main loop and no calls from ISRs...)
Unless you have the resources to avoid reentrancy on non-reentrant lwIP 
functions, of course.