Other Parts Discussed in Thread: LM3S6911
I am experiencing an issue with the lwip stack 1.4.1 on the TM4C1292NCPDT chip. After a variable amount of time, generally at least eight hours, of TCP communications and responses, the TCP port abruptly stops responding to TCP packets. Using debug code and wireshark, I can trace the incoming packets through the lwip stack and into the application layer, see that a response is generated in my application layer, but the response never exits the stack, and further TCP communication is impossible. Using lwip stats, I can see that on a failed unit the TCPmemerror counter gets to some huge numbers of events, many tens of thousands. Before failure, TCPmemerror does not report any events.
UDP communication is unaffeced, and TCP communication over a different connection is also possible.
For many years, and many thousands of devices, I had used the LM3S6911 TI's lwip 1.3.0 port, without a single occurrence of this issue. It would appear that this is an issue with the TCP send mechanism in lwip 1.4.1.
This post seemed promising, but implementing the fix outlined did not solve the problem: http://e2e.ti.com/support/microcontrollers/tiva_arm/f/908/p/374100/1316428#1316428