[lwip-users] tcpip_init(...) behavior when no Ethernet cable connected

[Dany Thiffeault]

Hi,

I'm using Atmel (AVR32) suggestion on how to configure the lwip stack. Here is a code sample:

[thread]

...

sys_sem_t sem;

sem = sys_sem_new(0);

// Initialize the lwIP stack.

tcpip_init(TcpIpInitDone, &sem);

// Block until the lwIP stack is initialized.

sys_sem_wait(sem);

...

// Callback executed when the TCP/IP init is done.

static void TcpIpInitDone(void *arg)

{

    sys_sem_t *sem;

    sem = (sys_sem_t *)arg;

    // Signal the waiting thread that the TCP/IP init is done.

    sys_sem_signal(*sem);

}

This is to be sure that the initialization is done when the function returns, because it's a multithread project using RTOS. So, when my network cable is connected, everything is fine. When it is not connected. I never unblock from the semaphore until I connect one. This is a little problematic for me since at that moment, my watchdog is active (and must be), so I get constant resets.

I know I can probably change my code to make this work, but I was curious to know if  there was a way to start the stack without a cable, successfully and be in a state like if I had a cable and I disconnected it after startup. At flag maybe, or another method?

Thanks a lot,

Dany