From owner-freebsd-hackers Fri Feb 9 11:57:40 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id LAA06119 for hackers-outgoing; Fri, 9 Feb 1996 11:57:40 -0800 (PST) Received: from phaeton.artisoft.com (phaeton.Artisoft.COM [198.17.250.211]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id LAA06114 for ; Fri, 9 Feb 1996 11:57:38 -0800 (PST) Received: (from terry@localhost) by phaeton.artisoft.com (8.6.11/8.6.9) id MAA10958; Fri, 9 Feb 1996 12:54:16 -0700 From: Terry Lambert Message-Id: <199602091954.MAA10958@phaeton.artisoft.com> Subject: Re: PCI problem To: luigi@labinfo.iet.unipi.it (Luigi Rizzo) Date: Fri, 9 Feb 1996 12:54:16 -0700 (MST) Cc: hackers@FreeBSD.ORG In-Reply-To: <199602091649.RAA02789@labinfo.iet.unipi.it> from "Luigi Rizzo" at Feb 9, 96 05:49:05 pm X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@FreeBSD.ORG Precedence: bulk > As you can see, the two network cards share the same int line, even > though the kernel believes they are at int 11 and 10 respectively. > > Any ideas on what can be going on ? The motherboard is an Intel Zappa. Yeah. The kernel is wrong. The PCI bus is right. By default, the kernel will have assigned "guesses" for devices. This derives from not having all devices in a "PlugNPlay" framework and/or probe registration mechanism. Windows95 calls this a "Resource Manager". The cards have the same interrupt assigned by the PCI BIOS. It is the responsibility of the OS to understand PCI interrrupt multiplexing and Deal With It(tm). Very few OS's currently do this because almost all motherboard manufacturers except the Intel OEM products division consider it a mistake to not have an interrupt per PCI slot. You will need to specifically override one of the cards idea of the "correct" interrupt (some PCI card hardware supports jumpering of ISA interrupts), you will need to override the single interrupt assignment on the motherboard (not possible on some Intel boards), or you will need to modify the interrupt handling mechanism (if it hasn't already been done) to support demuxxing the cards. In the last case, it is correct for the cards to have the same interrupt. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.