Re: [lwip-users] Infinite hang in tcp_slowtmr()

[Sylvain Rochet]

Hi Stephen,

On Tue, Oct 13, 2015 at 10:15:42AM +0200, Sylvain Rochet wrote:
> On Mon, Oct 12, 2015 at 04:59:19PM -0500, Stephen Cowell wrote:
> > On 10/12/2015 3:41 PM, Sylvain Rochet wrote:
> > >
> > > On Mon, Oct 12, 2015 at 02:51:14PM -0500, Stephen Cowell wrote:
> > > > I find that I sometimes get an infinite loop when stepping to
> > > > pcb->next...
> > > I didn't have to read further. As usual, it looks like a broken port or
> > > usage which violate lwIP threading model.
> > >
> > > Summary:
> > >
> > > - Do *NOT* call anything in interrupt context, nothing, never,
> > > absolutely never, use your OS semaphore signaling to an
> > > Ethernet/serial/… RX thread
> > 
> > I don't think I'm doing that, Sylvain... this is non-OS, so there
> > are no 'threads'.   Atmel wrote the port.  I'm running sntp and ftpd, they
> > hook in using their own _init() routines that have not been
> > modified.
> 
> But there are probably interrupts, which is even worse. Could you first 
> check that no lwIP functions are called in interrupts contexts ? 
> Probably around the macb driver.
> 
> If I have time I will fetch the Atmel port for SAM4E/bare-metal and 
> take a short look at it.

It looks sane from a quick look. I don't really understand why there are 
not using sys_check_timeouts() and rewrote everything in the ethernet.c 
"static timers_info_t gs_timers_table[]" stuff. Since you are having 
issue in timers context could you check this part is ok ? Removing all 
the Atmel timers stuff and calling sys_check_timeouts() in the main loop 
could be an easy check.

Sylvain