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From: Luigi Rizzo <luigi@labinfo.iet.unipi.it>
Message-Id: <199602091746.SAA02888@labinfo.iet.unipi.it>
Subject: Re: scanpci.c and pci-related stuff
To: terry@lambert.org (Terry Lambert)
Date: Fri, 9 Feb 1996 18:46:09 +0100 (MET)
Cc: se@zpr.uni-koeln.de, hackers@FreeBSD.org
In-Reply-To: <199602091713.KAA10691@phaeton.artisoft.com> from "Terry Lambert" at Feb 9, 96 10:13:00 am
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Thanks Terry for the interesting description.

BTW: a hint on how to fill up the handbook: just post a question for
every missing section, and hope someone will respond...


> > I have two identical PC-net PCI boards, plugged in adjacent slots.
> > On one particular motherboard they are both configured with IRQ10, on a
> > similar motherboard one gets IRQ10, the other IRQ11
> 
> Apparantly, the motherboards are not that similar...

Or maybe I am mistaken and they both gets assigned the same IRQ but
different from the first case...

...
> Make sure the ISA portion of your motherboard is PlugNPlay capable
> and that *all* your ISA cards are PlugNPlay cards, and you won't
> have this problem.

i.e. "avoid the problem and you won't have the problem". I'll keep in
mind next time... :)

> I'd guess that the board where multiple PCI's are getting assigned the
> same interrupt is a "Genuine Intel" motherboard, probably a Zappa.

good guess

> The PCI motherboards from the Intel OEM products division assign the
> same interrupt to all PCI slots.  It is up to the interrupt handling

isn't it "the same interrupt to all boards with the same PCI id ?"
otherwise why the meteor and the ethernet get different IRQs ?

> in your OS software to realize that this is allowable (but never
> desirable, Intel, if you are listening) under the spec to require the
> OS to demux PCI interrupts.
> 
> In general, there are Intel motherboards that "Do The Right Thing", but
> Intel typically does not sell them (as Rod Grimes about this one).  I
> recommend against Intel OEM Products Division boards.

so what are your recommendations ? For comparable prices, of course.

	Thanks
	Luigi
====================================================================
Luigi Rizzo                     Dip. di Ingegneria dell'Informazione
email: luigi@iet.unipi.it       Universita' di Pisa
tel: +39-50-568533              via Diotisalvi 2, 56126 PISA (Italy)
fax: +39-50-568522              http://www.iet.unipi.it/~luigi/
====================================================================