From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965245AbVKBVNw (ORCPT ); Wed, 2 Nov 2005 16:13:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965246AbVKBVNw (ORCPT ); Wed, 2 Nov 2005 16:13:52 -0500 Received: from perpugilliam.csclub.uwaterloo.ca ([129.97.134.31]:53665 "EHLO perpugilliam.csclub.uwaterloo.ca") by vger.kernel.org with ESMTP id S965245AbVKBVNv (ORCPT ); Wed, 2 Nov 2005 16:13:51 -0500 Date: Wed, 2 Nov 2005 16:13:50 -0500 To: tcrix@att.net Cc: Linux Kernel Mailing List Subject: Re: No sharing IRQ broken board problem Message-ID: <20051102211350.GD9488@csclub.uwaterloo.ca> References: <110220052106.23704.43692A6C000AA6AE00005C98215876675598079D0C9B@att.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <110220052106.23704.43692A6C000AA6AE00005C98215876675598079D0C9B@att.net> User-Agent: Mutt/1.5.9i From: lsorense@csclub.uwaterloo.ca (Lennart Sorensen) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 02, 2005 at 09:06:53PM +0000, tcrix@att.net wrote: > I have a pci board in development that works but.. > it can not share the interrupt line. > > Has someone hacked through the problem of reserving one of the inta, intb, .. 's for a single device? I would love to see how you did so I could continue on with my driver while I wait for the !@$#!@ hardware guys to fix the board. As far as I understand the PCI specs, your device is currently NOT a PCI device. Support for shared IRQs on PCI is as far as I can tell not optional. Short of designing your own mainboard there is no way to prevent the interrupt lines from being joined. One one board I use there are 6 PCI devices, with 3 on INT-A and 3 on INT-B (The SBC doesn't have INT-C and INT-D). On my desktop machine, INT A is the same on slot 1 and 5, 2, and 6 and onyl 3 and 4 have INT-A to themselves. Of course this doesn't prevent the bios from assigning the same IRQ to INT-A on multiple sets as well. I have run a PPro some years ago with a single IRQ shared among all the PCI devices in the system. Neither linux nor windows had a problem with that and neither did any of the many PCI devices. I think you are stuck waiting for the hardware guys to give you a PCI device that is really a PCI device. If you are lucky you can find one slot in your machine that doesn't share INT-A with any other PCI device, although on most modern machines there are so many PCI devices that it is imposible to find one that isn't shared. Len Sorensen