From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: Multiple MSI, take 3 Date: Fri, 11 Jul 2008 04:34:19 -0700 Message-ID: References: <20080711005719.GO14894@parisc-linux.org> <20080711102326.GR14894@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from out02.mta.xmission.com ([166.70.13.232]:33131 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751340AbYGKLmI (ORCPT ); Fri, 11 Jul 2008 07:42:08 -0400 In-Reply-To: <20080711102326.GR14894@parisc-linux.org> (Matthew Wilcox's message of "Fri, 11 Jul 2008 04:23:26 -0600") Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Matthew Wilcox Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, grundler@parisc-linux.org, mingo@elte.hu, tglx@linutronix.de, jgarzik@pobox.com, linux-ide@vger.kernel.org, suresh.b.siddha@intel.com, benh@kernel.crashing.org, jbarnes@virtuousgeek.org, rdunlap@xenotime.net, mtk.manpages@gmail.com There is one idea that seems to model this cleanly without breaking all kinds of expectations. That is an irq with a very small data payload. In that case we wire all of the vectors up to a single irq handler that computes the payload as: payload = vector - base-vector. And then we figure out how to pass that to the handler in irqaction. To most of the system it is a single irq so it avoids breaking expectations about what an irq is. To everything else it is a little odd, and has it's own unique set of rules (which is good as well). Eric