Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264117AbUD0Opb (ORCPT ); Tue, 27 Apr 2004 10:45:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264147AbUD0Opb (ORCPT ); Tue, 27 Apr 2004 10:45:31 -0400 Received: from chaos.analogic.com ([204.178.40.224]:31617 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id S264117AbUD0Op3 (ORCPT ); Tue, 27 Apr 2004 10:45:29 -0400 Date: Tue, 27 Apr 2004 10:47:23 -0400 (EDT) From: "Richard B. Johnson" X-X-Sender: root@chaos Reply-To: root@chaos.analogic.com To: "Srinivas G." cc: linux-kernel@vger.kernel.org Subject: Re: How to handle interrupts on SMP systems In-Reply-To: <1118873EE1755348B4812EA29C55A9721D6CC7@esnmail.esntechnologies.co.in> Message-ID: References: <1118873EE1755348B4812EA29C55A9721D6CC7@esnmail.esntechnologies.co.in> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1601 Lines: 44 On Tue, 27 Apr 2004, Srinivas G. wrote: > > Hi, > > We developed a driver for PCIHOTLINK card under linux kernel 2.4.18-3. > It was working fine under it. Now our idea is to port it SMP system with > the same kernel. We ported. It was compiled without any problem under > SMP system. But it is not generating any interrupts. We have changed the > Makefile also. We added -D__SMP__ macro and -DCONFIG_SMP macro in > Makefile. No compilation errors. But interrupts are not generating. > > If anybody will have any idea please let me know. > > Thanks in advance, > > Regards, > > Srinivas G There is no difference between SMP and non-SMP systems as far as interrupt generation is concerned. You might have a hardware- initialization bug that shows up only when you use some SMP macros. Make sure you are using the proper macros to access your hardware and not just pretending the return value of ioremap_nocache() is a pointer (it's not, it's a cookie). Also SMP adds some additional code. So, it might change the degree of optimization that the compiler performs. You need to use the 'volatile' key-word in cases where the compiler might not otherwise know that something could get changed in an interrupt. Cheers, Dick Johnson Penguin : Linux version 2.4.26 on an i686 machine (5557.45 BogoMips). Note 96.31% of all statistics are fiction. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/