Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765221AbXEYUf2 (ORCPT ); Fri, 25 May 2007 16:35:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757308AbXEYUfR (ORCPT ); Fri, 25 May 2007 16:35:17 -0400 Received: from mail.suse.de ([195.135.220.2]:56270 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756764AbXEYUfQ (ORCPT ); Fri, 25 May 2007 16:35:16 -0400 Date: Fri, 25 May 2007 13:35:01 -0700 From: Greg KH To: "Eric W. Biederman" Cc: Jay Cliburn , Grzegorz Krzystek , Andrew Morton , Andi Kleen , ninex@o2.pl, linux-kernel@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz, Michael Ellerman , David Miller , Tony Luck Subject: Re: [PATCH 1/2] msi: Invert the sense of the MSI enables. Message-ID: <20070525203501.GD5413@suse.de> References: <20070514160005.627435e3@osprey.hogchain.net> <20070515212200.517fcba2@osprey.hogchain.net> <20070516185225.3f3ac082@osprey.hogchain.net> <20070522204103.134bf5a2@osprey.hogchain.net> <20070525052032.GB9386@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.15 (2007-04-06) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2261 Lines: 53 On Fri, May 25, 2007 at 09:17:35AM -0600, Eric W. Biederman wrote: > Greg KH writes: > > > Originally I would have thought this would be a good idea, but now that > > Vista is out, which supports MSI, I don't think we are going to need > > this in the future. All new chipsets should support MSI fine and this > > table will only grow in the future, while the blacklist should not need > > to have many new entries added to it. > > > > So I don't think this is a good idea, sorry. > > - The current situation is broken > - In spec hardware does not require MSI to generate interrupts > Which leaves enabling MSI optional. > > Do you have a better idea to solve the current brokenness? > > MSI appears to have enough problems that enabling it in a kernel > that is supposed to run lots of different hardware (like a distro > kernel) is a recipe for disaster. Oh, I agree it's a major pain in the ass at times... But I'm real hesitant to change things this way. We'll get reports of people who used to have MSI working, and now it will not (like all AMD chipsets). That's a regression... Perhaps we can trigger off of the same flag that Vista uses like Andi suggested? That's one way to "know" that the hardware works, right? For non-x86 arches, they all seem to want to always enable MSI as they don't have to deal with as many broken chipsets, if any at all. So for them, we'd have to just whitelist the whole arch. Does that really make sense? And again, over time, like years, this list is going to grow way beyond a managable thing, especially as any new chipset that comes out in 2009 is going to have working MSI, right? I think our blacklist is easier to manage over time, while causing a problem for some users in trying to determine their broken hardware that they currently have. It's a trade off, and I'd like to choose the one that over the long term, causes the least ammount of work and maintaiblity. I think the current blacklist meets that goal. thanks, greg k-h - 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/