Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933151Ab2JSXCN (ORCPT ); Fri, 19 Oct 2012 19:02:13 -0400 Received: from mga02.intel.com ([134.134.136.20]:12627 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933108Ab2JSXCL (ORCPT ); Fri, 19 Oct 2012 19:02:11 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,617,1344236400"; d="scan'208";a="208308036" Subject: Re: x2apic boot failure on recent sandy bridge system From: Suresh Siddha Reply-To: Suresh Siddha To: rrl125@gmail.com Cc: fa.linux.kernel@googlegroups.com, "Berck E. Nash" , Yinghai Lu , "linux-kernel@vger.kernel.org" , "H. Peter Anvin" Date: Fri, 19 Oct 2012 16:03:58 -0700 In-Reply-To: References: Organization: Intel Corp Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.0.3 (3.0.3-1.fc15) Content-Transfer-Encoding: 7bit Message-ID: <1350687838.6017.10.camel@sbsiddha-desk.sc.intel.com> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1834 Lines: 41 On Fri, 2012-10-19 at 13:42 -0700, rrl125@gmail.com wrote: > Any update? The messages just seem to have stopped months ago. A > fallback would be nice, I have been booting the kernel with noa2xpic > for since kernel 3.2, and currently I am working with 3.6.2. > > If needed I can try to attempt modifying the patch to include > fallback, but I am probably not the best person to do it. > Are you referring to this commit that made into the mainline tree already? commit fb209bd891645bb87b9618b724f0b4928e0df3de Author: Yinghai Lu Date: Wed Dec 21 17:45:17 2011 -0800 x86, x2apic: Fallback to xapic when BIOS doesn't setup interrupt-remapping On some of the recent Intel SNB platforms, by default bios is pre-enabling x2apic mode in the cpu with out setting up interrupt-remapping. This case was resulting in the kernel to panic as the cpu is already in x2apic mode but the OS was not able to enable interrupt-remapping (which is a pre-req for using x2apic capability). On these platforms all the apic-ids are < 255 and the kernel can fallback to xapic mode if the bios has not enabled interrupt-remapping (which is mostly the case if the bios has not exported interrupt-remapping tables to the OS). Reported-by: Berck E. Nash Signed-off-by: Yinghai Lu Link: http://lkml.kernel.org/r/20111222014632.600418637@sbsiddha-desk.sc.intel.com Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin -- 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/