From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261717AbVFGFQH (ORCPT ); Tue, 7 Jun 2005 01:16:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261719AbVFGFQH (ORCPT ); Tue, 7 Jun 2005 01:16:07 -0400 Received: from lyle.provo.novell.com ([137.65.81.174]:45157 "EHLO lyle.provo.novell.com") by vger.kernel.org with ESMTP id S261717AbVFGFQD (ORCPT ); Tue, 7 Jun 2005 01:16:03 -0400 Date: Mon, 6 Jun 2005 22:15:51 -0700 From: Greg KH To: Andrew Vasquez Cc: Jeff Garzik , "David S. Miller" , tom.l.nguyen@intel.com, roland@topspin.com, linux-pci@atrey.karlin.mff.cuni.cz, linux-kernel@vger.kernel.org, ak@suse.de Subject: Re: [RFC PATCH] PCI: remove access to pci_[enable|disable]_msi() for drivers Message-ID: <20050607051551.GA17734@suse.de> References: <20050607002045.GA12849@suse.de> <20050607010911.GA9869@plap.qlogic.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050607010911.GA9869@plap.qlogic.org> User-Agent: Mutt/1.5.8i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 06, 2005 at 06:09:11PM -0700, Andrew Vasquez wrote: > On Mon, 06 Jun 2005, Greg KH wrote: > > > > > Ok, as it seems there is a bit of confusion, here's real code that > > should help explain what I am proposing. This works on my desktop, but > > I don't think it supports MSI :) > > > > I'll go dig out an old 4-way AMD box that has MSI to see if this still > > works properly, but comments are welcome. > > > Thanks for posting some sample code. Some comments though: > > * What if the driver writer does not want MSI enabled for their > hardware (even though there is an MSI capabilities entry)? Reasons > include: overhead involved in initiating the MSI; no support in some > versions of firmware (QLogic hardware). Yes, a very good point. I guess I should keep the pci_enable_msi() and pci_disable_msi() functions exported for this reason. > * A device (notably, our 4gb PCIe fibre-channel products) can support > both MSI and MSI-X. Since the driver has no way of 'disabling' MSI, > how would it enable MSI-X? Agreed, let me respin the patches again, because I think I got the logic wrong on some of these drivers because of this... thanks, greg k-h