From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261983AbULKRhE (ORCPT ); Sat, 11 Dec 2004 12:37:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261984AbULKRg6 (ORCPT ); Sat, 11 Dec 2004 12:36:58 -0500 Received: from NEUROSIS.MIT.EDU ([18.95.3.133]:52963 "EHLO neurosis.jim.sh") by vger.kernel.org with ESMTP id S261983AbULKRfm (ORCPT ); Sat, 11 Dec 2004 12:35:42 -0500 Date: Sat, 11 Dec 2004 12:35:38 -0500 From: Jim Paris To: linux-kernel@vger.kernel.org Subject: PCI IRQ problems -- update Message-ID: <20041211173538.GA21216@jim.sh> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.6+20040722i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is an update on my laptop's IRQ problem I mentioned back in Oct: http://lkml.org/lkml/2004/10/15/20 In short, all PCI IRQs are routed via ACPI to PIC IRQ 9. When the PIIX IDE device is enabled, it pulls on that interrupt until it gets disabled ("nobody cared"). ide0 then continues to work on IRQ 14, but all other devices are broken since IRQ 9 is disabled. My previous solution was to use Alan Cox's "irqpoll" patch which allowed the other devices to still function. That's a hack and I wanted to find a real way to fix it. It turns out that IDE is the only device connected to LNKC. I changed the ACPI DSDT so that LNKC points to the unused IRQ 5, and all of my problems magically went away. This is still a hack, but seems to work. I'm not sure how to get to the root cause of the problem, though. For starters: where _should_ the INTA of the IDE card go, if anywhere? If my laptop's IDE is routed to and pulling on IRQ 9, how can it still be functioning on IRQ 14? Or, if the routing doesn't matter, is there anything I can do to prevent it from pulling on 9? -jim