Jean Tourrilhes <[EMAIL PROTECTED]> writes:
> While waiting for my new dongle to arrive, I was playing a bit
> more with the old_belkin driver (by the way, Dag, any chance of having
> it in your patches ?).
Yes, I've applied it and fixed the Config.in and Makefile as well. But
could you write something for Documentation/Configure.help?
> I've discovered that the IrDA stack is very flaky at
> 9600. While with a normal dongle at slow speed (19200 for example)
> things are working OK, at 9600 things are really messy. I manage to
> connect (for example via IrComm or IrLan), but after a few second or
> when I try to do a bit of real stuff, then the connection freeze and
> no traffic goes through at all.
> irdadump show me still some LAP activity every second (cmd/rsp
> pairs), but no high level activity. In kernel messages, LAP claim that
> there is no longer any activity and that it has disconnected my
> connection.
>
> As far as I can tell, this has nothing to do with the dongle
> driver (I go through a few change speed without a sweat and packets
> are still flowing at the LAP layer). I feel that this is a weird
> interaction in the IrDA stack when at 9600.
> Dag, this one should be really easy for you to test out : take
> your favourite dongle driver and limit it to 9600...
Don't think I have to test it to figure out what's wrong. How much time
does the machine use to transmit a 2K frame (actually 2050 bytes + framing
and stuffing) over a 9600bps link? Remember that the max turn time is 500
ms. Yes, we need to make sure we don't allow such large frames at such a
low speed. I hasn't been fixed yet, since I don't think anybody has tried
this before ;-)
>From the IrLAP spec 6.6.5 (page 40):
... "The actual maximum frame size for the connection must be adjusted to
accommodate the baud rate and maximum turn around time." ...
-- Dag
--
/ Dag Brattli | The Linux-IrDA Project /
// University of Tromsoe, Norway | Infrared communication for Linux //
/// http://www.cs.uit.no/~dagb | http://www.cs.uit.no/linux-irda/ ///
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