Re: Ctrl-C interrupt problem.

[Fernando Nasser <fnasser@cygnus.com>]

Nice catch Fabrice.

Congratulations on your persistence.

Fernando



Mark Salter wrote:
> 
> >>>>> Fabrice Gautier writes:
> 
> > [eCos and RedBoot guys, I think this may concern you
> >  its about a ctrl-C problem which only happen when debugging via ethernet.
> >  full story in the gdb list archives ]
> 
> > I Got it!
> > Well, i hope....
> 
> > And it make sens why it only happens with TCP...
> 
> > The problem is that when gdb send the continue packet to the target, it wait
> > for the target to send the '+' Ack. During this time the SIGINT handler is
> > not set.
> 
> > My guess is that RedBoot intedn to send it BUT (tata) the ethernet driver
> > just wait to have a full packet before really sending! So this happen when a
> > O packet is sent.
> 
> > So i guess the only thing needed in RedBoot is to add a "flush" somewhere.
> > I'm not sure at what level, but i'll look at it tomorrow if nobody does it
> > before.
> 
> > Thanks
> 
> > --
> > Fabrice Gautier
> > fabrice_gautier@sdesigns.com
> 
> Yes, it appears that redboot only flushes the output stream when
> it sees the end of a packet. This causes the problem you see.
> 
> Look at .../redboot/current/src/net/net_io.c:net_io_putc().
> 
> A quick workaround would be to also flush if a '+' is seen. This
> has a downside as it may severely impact download speeds, but at
> least it is functionally correct. YMMV.
> 
> This needs to be fixed with a flush of the output stream prior
> to continuing or stepping the target. Its not clear to me right
> now how this can be done.
> 
> --Mark


-- 
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
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Toronto, Ontario   M4P 2C9