Re: [ECOS] network problem

[Andrew Lunn <andrew.lunn@ascom.ch>]

On Fri, Jan 11, 2002 at 05:27:33PM +0100, Andrea Acquaviva wrote:
> Hi,
> 
> I found a problem while using the CF ethernet interface on assabet
> board.
> After the network initialization made by init_all_network_interfaces(),
> I put the program in an idle state (while(1)) and I try to ping the
> interface. The interface reply to the ping request for a certain amount
> of time and then blocks.
> The strange thing is that this amount of time increase if I add some
> debugging output when the packet are received.
> 
> Someone can suggest me an explanation?

Remember that eCos is an RTOS. A high priority thread which is
runnable will always be run instead of a low priority thread. The
network stack is implemented as threads as well. So if your endless
loop is running at a higher priority then the network stack, don't
expect the network stack to work.

Now the strange thing. You say it works for a while. That i don't
understand. It should work, or it should not work. What are you
actually pinging. The application stack or the redboot stack? The
redboot stack may keep working under these conditions since its not
thread based. The debug output would also help since it gives redboot
more time to actually process network traffic for it. 

Also, some network drivers have a low priority tickle thread. This
thread is used to recover from hardware errors in some ethernet
devices. They lockup under some conditions and the tickle thread will
bring them back to life. Maybe your endless loop is stopping this
tickle thread and so you are seeing the hardware error.

       Andrew