Date: Fri, 27 Jun 1997 02:59:46 -0700 From: David Greenman <dg@root.com> To: Stefan Esser <se@freebsd.org> Cc: Jon Inouye <jinouye@cse.ogi.edu>, freebsd-hardware@freebsd.org Subject: Re: IRQ assignment for PII motherboards Message-ID: <199706270959.CAA15026@implode.root.com> In-Reply-To: Your message of "Fri, 27 Jun 1997 11:40:22 %2B0200." <19970627114022.32725@mi.uni-koeln.de>
next in thread | previous in thread | raw e-mail | index | archive | help
>On Jun 26, David Greenman <dg@root.com> wrote: >> I was able to get the Pro/100B, in a system with a pair of ahc3940's, to >> get assigned to a non-shared interrupt by playing around with which slots >> the cards were plugged into. It took about 3 tries to find the right order >> (including leaving a slot empty), but I finally found an arrangement that >> worked. My understanding is that the shared irq assignment isn't a function >> of the BIOS, but rather a function of the slot the card is in and how it >> is wired compared to the others. The motherboard I did this in wasn't made >> by Intel, but the same principles should still apply. > >Interrupts should not be shared, unless at least one PCI card >in the system either: > >1) contains a PCI to PCI bridge, or >2) contains a multi-function PCI chip. Yes, the aha3940's are dual-channel SCSI adapters and have a bridge chip on each card to connect the two SCSI chips. This seems to make the determination of which interrupts will be shared on how they are shared very difficult or impossible. Is there a scheme to the sharing when bridge chips are involved? -DG David Greenman Core-team/Principal Architect, The FreeBSD Project
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199706270959.CAA15026>