Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753789AbZDRHYo (ORCPT ); Sat, 18 Apr 2009 03:24:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751646AbZDRHYg (ORCPT ); Sat, 18 Apr 2009 03:24:36 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:59103 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751310AbZDRHYf (ORCPT ); Sat, 18 Apr 2009 03:24:35 -0400 Date: Sat, 18 Apr 2009 09:24:14 +0200 From: Ingo Molnar To: Suresh Siddha Cc: "Han, Weidong" , Jesse Barnes , "dwmw2@infradead.org" , "Kay, Allen M" , "Yu, Fenghua" , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" Subject: Re: [PATCH 3/5] x86, intr-remap: enable interrupt remapping early Message-ID: <20090418072414.GF7678@elte.hu> References: <1239957736-6161-1-git-send-email-weidong.han@intel.com> <1239957736-6161-4-git-send-email-weidong.han@intel.com> <20090417141310.GD23493@elte.hu> <1240011743.27006.8496.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1240011743.27006.8496.camel@localhost.localdomain> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1850 Lines: 49 * Suresh Siddha wrote: > On Fri, 2009-04-17 at 07:13 -0700, Ingo Molnar wrote: > > * Weidong Han wrote: > > > > > --- a/arch/x86/kernel/apic/apic.c > > > +++ b/arch/x86/kernel/apic/apic.c > > > @@ -118,6 +118,8 @@ static int x2apic_preenabled; > > > static int disable_x2apic; > > > static __init int setup_nox2apic(char *str) > > > { > > > + if (x2apic_enabled()) > > > + panic("Bios already enabled x2apic, can't enforce nox2apic"); > > > > Could you please turn that into something like: > > I have couple of patches cleaning these up(including some > warnings). I will post them shortly. ok! > > > +ir_failed: > > > + if (x2apic_preenabled) > > > + panic("x2apic enabled by bios. But IR enabling failed"); > > > > What is the likelyhood that we can continue in compat mode? If > > there's some chance, we should rather print a KERN_WARNING and > > should try to continue. If IRQs are not coming we'll hang shortly > > afterwards anyway. > > Typically only on high end platforms we will see x2apic enabled by > BIOS before OS handover. And in these cases, BIOS should have > already enabled interrupt-remapping in extended interrupt mode, > before handing over control to OS. If the extended interrupt mode > is set, HW will block the compatibility format interrupts anyway. > And I think its better to panic rather than hanging at random > places(depending on which interrupts are already in remapped > format and which are not). This way, it will be easy for anyone to > figure out what is happening. fair enough. Ingo -- 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/