tcp_debug

[Richard M. Barry]

I'm debugging a network driver I wrote and I have the following problem:
 
In the network documentation, under the Testing the Driver, there are instructions on how to enable the IP stack to print state transitions (by defining TCPDEBUG and changeing the tcpconsdebug variable to 1 in tcp_debug.c).   I did this, but I see no output from the IP stack (I'm using netdemo as a test app).   I can see the driver enqueing the packets to the network stack, and it looks like the stack is dequeing them (I see the IF_ENQUEUE adn IF_DEQUEUE output) , but there's no output from tcp_trace().   It also looks like the stack then enques the (ping) reply and wakes up the transmit task in the driver to transmit it, but I don't receive anything at the receiving end (ie the ping times out).   How can the stack receive and answer without any debugging output from tcp_trace()?   I most probably have a problem with the message envelope (it arrives over HDLC, not ethernet) and my transmit task, but that still does not answer the question about why the stack seems to be active, but tcp_trace() isn't called.
 
My next step is to physically look what's happening on the line using a scope or a snooper, but I'd like to understand why I'm not getting debugging prints from the strack first.
 
Regards,
Richard