Date: Tue, 12 May 1998 18:21:13 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: dg@root.com Cc: steve@visint.co.uk, tlambert@primenet.com, freebsd-current@FreeBSD.ORG Subject: Re: Intel Etherexpress PRO/100+ PCI Message-ID: <199805121821.LAA23722@usr04.primenet.com> In-Reply-To: <199805121212.FAA23850@implode.root.com> from "David Greenman" at May 12, 98 05:12:58 am
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> >% I find it unlikely that they are both on INT a. This may be a bug in > >% the probe routines, or in your motherboard BIOS. It could also account > >% for the start IRQ (say one was on 'INT b', but it wasn't seen). > > > >I think this is possibly probe related, although I can't be sure, but I've > >just checked another six machines none of which use are probed as using > >anything but int A. > > Terry just doesn't understand how interrupts work on the PCI bus, despite > providing a nice picture. :-) All of the PCI cards with a single interrupt > will use INT A - that's just how it works and is the reason for the interrupts > being cascaded the way they are on the bus. INT A on one slot is not the same > interrupt on another. ??? Uh, that's what I said. I think it's unlikely that cards in two different slots will have INT a assigned to them, unless the bus lines are *not* cascaded, which I also think is unlikely on a modern motherboard. Why are both cards reported on INT a? > That's not your goal. You want them to each use a different _irq_ not > a different INT letter. ...but none of this matters because it's not what > is causing your problem. :-) Well, you want them to use a different PCI input line, of which there are four on most chipsets not manufactured by DEC or Apple, and which are lettered a through d. Are we asking the card where it thinks it is? If so, how are we getting the INT b's from slot 2 to the interrupt handler? I think it's more useful to report the ID seen by the handler than the ID seen by the card, especially for something like a dual channel Adaptec controller leaching two interrupts (INT a from it's slot, and INT b from the adjacent slot -- wrapping around at the end of the bus). Am I just not understanding that what's being reported isn't what's being set up in the IRQ handler list? If so, this seems wrong... Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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