From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261713AbVFGEVM (ORCPT ); Tue, 7 Jun 2005 00:21:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261715AbVFGEVM (ORCPT ); Tue, 7 Jun 2005 00:21:12 -0400 Received: from colo.lackof.org ([198.49.126.79]:64437 "EHLO colo.lackof.org") by vger.kernel.org with ESMTP id S261713AbVFGEVG (ORCPT ); Tue, 7 Jun 2005 00:21:06 -0400 Date: Mon, 6 Jun 2005 22:24:42 -0600 From: Grant Grundler To: Jeff Garzik Cc: Greg KH , "David S. Miller" , tom.l.nguyen@intel.com, linux-pci@atrey.karlin.mff.cuni.cz, linux-kernel@vger.kernel.org, roland@topspin.com Subject: Re: pci_enable_msi() for everyone? Message-ID: <20050607042442.GA12781@colo.lackof.org> References: <20050603224551.GA10014@kroah.com> <20050605.124612.63111065.davem@davemloft.net> <20050606225548.GA11184@suse.de> <42A4D771.7080400@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <42A4D771.7080400@pobox.com> X-Home-Page: http://www.parisc-linux.org/ User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 06, 2005 at 07:08:33PM -0400, Jeff Garzik wrote: > Not only the differences DaveM mentioned, but also simply that you may > assume your interrupt is not shared with anyone else. I had the impression the CPU vector could be shared. But PCI 2.3 spec says: | An MSI is by definition a non-shared interrupt that enforces data | consistency (ensures the iterrupt service routine accesses the most | recent data). The system guarantees that any data written by the | device prior to sending the MSI has reached its final destination | before the interrupt service routine accesses that data. Therefore, | a device driver is not required to read its device before servicing | its MSI. I guess that's pretty clear.... grant