From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: linux-next: Tree for June 13: IO APIC breakage on HP nx6325 Date: Mon, 30 Jun 2008 02:45:44 +0200 Message-ID: <20080630004544.GB19093@one.firstfloor.org> References: <20080613232214.394fd6fd.sfr@canb.auug.org.au> <20080629200210.GB31633@elte.hu> <200806300106.38414.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from one.firstfloor.org ([213.235.205.2]:52131 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752966AbYF3AeA (ORCPT ); Sun, 29 Jun 2008 20:34:00 -0400 Content-Disposition: inline In-Reply-To: <200806300106.38414.rjw@sisk.pl> Sender: linux-next-owner@vger.kernel.org List-ID: To: "Rafael J. Wysocki" Cc: "Maciej W. Rozycki" , Ingo Molnar , Matthew Garrett , Stephen Rothwell , linux-next@vger.kernel.org, LKML , Thomas Gleixner , ACPI Devel Maling List , Len Brown , Andi Kleen , Andrew Morton , Linus Torvalds > > Otherwise you throw this burden onto users who > (1) don't expect things to stop working, > (2) may not be able to figure out themselves what the right workaround is, > (3) may not be able to make hardware manufacturers do anything. Right thing would be to revert the guilty patches until these problems are resolved. > > If there's a configuration that worked before your patch and doesn't work > after it, you're hurting the users of that configuration. ... also past experience is that DMI tables don't work well for this. We tried that early when ACPI was still very problematic and it turned out to be a flawed non-scalable strategy, Typically the configurations causing problems are in multiple motherboards with different DMI strings and it's very difficult to catch them all. Also sometimes BIOS behaviour changes over versions and that's tricky to catch with the standard DMI matches. One way that would half way scale is to check for specific configurations based on PCI-IDs and knowledge of the config space of these chipset, although it's also not ideal because often multiple chipset generations with different PCI-IDs have similar issues. -Andi