Hi Richard,
> It would seem buffers get overloaded, or something to that effect, ie, the
> 9k6 interface works twice as fast as the data can be retransimited on the
> 4k8 interface causing buffer/memory problems.
Assuming that you are using either z8530drv-2.4c in its network
driver mode or z8530drv-3.0 it is most likely not a buffer problem.
What seems to happen is that the driver looses not only one TX
interrupt but also the "exception" interrupt that notifies the
driver of the TX underrun. Even worse, it seems that in some cases
(probably depending on the mask version) the Z8530 needs a complete
re-initialization of that channel to be able to transmit again.
> There is no need to reboot to get over the problem a small script i have
> running via cron, checks the interface with pings every 15 minutes, no pings
> returned will cause ifconfig to restart the interface and all is well again.
I'd recommend a DMA capable SCC card instead.
> There are never any signs or messages anywhere which could give even the
> smallest hint of where to start looking for the problem.
Seems that I'll have to add yet another timer to monitor transmit
interrupts, sigh.
> I have explaned this problem to this list at least TWICE in the past, it is
> NOT only me that has this problem, a look at the archives will produce quite
> a few callsigns who all say they have the same symptoms in one way or
> another.
Yes, but messages with little more information than "it does not work under
high load" don't help much when trying to find the exact condition
causing it.
> Joreg DK1BKE has never responded to any of the comments, hints or kinks,
> made about this problem,
This is not true. I've responded to several of your mails, asked for
more information and never got any answers or replies afterwards. Seems
that the path to your mailbox is not very reliable.
> i have tryed many things different timings, MTU's,
> window sizes, buffsize in /etc/z8530drv.conf, parms settings, realy you name
> it i've tryed it, all to no avail, there is a problem with the SCC driver
> but as finding out what it is, is like banging your head against a wall.
Has it ever occured to you that the fault may not be a more or less
"buggy" SCC driver but rather broken SCC board design equiped with
broken second-source versions of Zilog's Z8530 on a broken PC
architecture?
> If there are others with this problem please speak now.
...and perhaps pass me copy when this happens, with the version of
the z8530drv you are using and the output of cat /proc/net/z8530drv.
73,
Joerg Reuter http://poboxes.com/jreuter/
And I make my way to where the warm scent of soil fills the evening air.
Everything is waiting quietly out there.... (Anne Clark)
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