From owner-freebsd-current Sat Oct 24 15:01:36 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA10820 for freebsd-current-outgoing; Sat, 24 Oct 1998 15:01:36 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from smtp04.primenet.com (smtp04.primenet.com [206.165.6.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA10812 for ; Sat, 24 Oct 1998 15:01:34 -0700 (PDT) (envelope-from tlambert@usr01.primenet.com) Received: (from daemon@localhost) by smtp04.primenet.com (8.8.8/8.8.8) id PAA05002; Sat, 24 Oct 1998 15:01:01 -0700 (MST) Received: from usr01.primenet.com(206.165.6.201) via SMTP by smtp04.primenet.com, id smtpd004980; Sat Oct 24 15:00:55 1998 Received: (from tlambert@localhost) by usr01.primenet.com (8.8.5/8.8.5) id PAA25750; Sat, 24 Oct 1998 15:00:52 -0700 (MST) From: Terry Lambert Message-Id: <199810242200.PAA25750@usr01.primenet.com> Subject: Re: 3.0 missing some docs? To: phk@critter.freebsd.dk (Poul-Henning Kamp) Date: Sat, 24 Oct 1998 22:00:52 +0000 (GMT) Cc: tlambert@primenet.com, dwhite@resnet.uoregon.edu, jeff-ml@mountin.net, freebsd-current@FreeBSD.ORG In-Reply-To: <6537.909182675@critter.freebsd.dk> from "Poul-Henning Kamp" at Oct 24, 98 00:44:35 am X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > >> It's a hardware-ism. IRQ 7 is the generic junk IRQ. > > > >I was under the impression that we had registered default handlers for > >all IRQ's, and thus 7 was no longer the grabage bin unless there > >was a deassert race that indicates a real problem? > > > >You should ask Bruce Evans for confirmation. > > IRQ is the i8259's garbage bin, regardless of config. If an IRQ is asserted > too short for classification by the i8259 it becomes irq7. Yeah; that's the race. I remember that when IRQ 2 was disabled in the interrupt controller, back before there were default handlers to catch and ack it if it were enabled, EGA cards with vertical retrace interrupt on IRQ 2 (for light pen support) used to get thrown onto 7 as "masked, unclassifiable". I think I remember something about unsupported portions of some sound cards throwing spurious interrupts with an open collector microphone input without a hold-down resistor, too. Anyway, my point is that it's much less "generic junk" now, and it probably indicates a real problem with some hardware that's asserting and then deasserting some other IRQ: in other words, there's some bad hardware on board that machine, it's not just an unexpected (but valid) interrupt from good hardware. 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