From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750936AbWFAX3E (ORCPT ); Thu, 1 Jun 2006 19:29:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750952AbWFAX3E (ORCPT ); Thu, 1 Jun 2006 19:29:04 -0400 Received: from shawidc-mo1.cg.shawcable.net ([24.71.223.10]:32600 "EHLO pd4mo2so.prod.shaw.ca") by vger.kernel.org with ESMTP id S1750936AbWFAX3C (ORCPT ); Thu, 1 Jun 2006 19:29:02 -0400 Date: Thu, 01 Jun 2006 17:28:52 -0600 From: Robert Hancock Subject: Re: io apic and shared irq questions In-reply-to: <6iROY-2Dc-17@gated-at.bofh.it> To: linux-kernel , sancelot@free.fr Message-id: <447F7834.50102@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit References: <6iROY-2Dc-17@gated-at.bofh.it> User-Agent: Thunderbird 1.5.0.2 (Windows/20060308) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org s.a. wrote: > Hi, > > Regarding an embedded realtime system, I have got a communication board > on pci bus . > > I would like it's interrupt not being shared (with usb) , because the > component receives an it every 100us and is realtime determinist. > I looked at how was routed IRQ's with the io apic , although it is able > to use 24 irq's, linux always share my PCI boards IRQ with another > component and do not use all the 24 irq's range capability of ioapic. > > Do you think it is possible to program the ioapic in order to have a > better irq mapping and avoid this problem and use all the range of > availbale vectors ? > > Best Regards > Steph This may depend on the hardware, but as far as I know, usually the IOAPIC interrupt mapping is the same as the physical wiring of the interrupt lines on the board. If the devices use the same physical interrupt line, there is no way to separate them. -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/