From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754496Ab1DUPKU (ORCPT ); Thu, 21 Apr 2011 11:10:20 -0400 Received: from mga02.intel.com ([134.134.136.20]:39151 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754444Ab1DUPKT (ORCPT ); Thu, 21 Apr 2011 11:10:19 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.64,251,1301900400"; d="scan'208";a="632092662" Date: Thu, 21 Apr 2011 23:12:50 -0400 From: Youquan Song To: Ingo Molnar Cc: Youquan Song , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, tglx@linutronix.de, hpa@zytor.com, hpa@linux.intel.com, suresh.b.siddha@intel.com, yong.y.wang@linux.intel.com, joe@perches.com, jbaron@redhat.com, trenn@suse.de, kent.liu@intel.com, chaohong.guo@intel.com, Youquan Song Subject: Re: [PATCH v4 1/2] apic: Fix error interrupt report at all APs Message-ID: <20110422031250.GA30016@linux-youquan.bj.intel.com> References: <1302762968-24380-1-git-send-email-youquan.song@intel.com> <20110419170121.GA6640@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110419170121.GA6640@elte.hu> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > I don't disagree with this change, but unfortunately the changelog is in > absolutely unreadable English. Please fix it or find someone who can fix it for > you. > > I decoded and fixed the changelog of the 2/2 patch of your series so no need to > do it for that patch. Thanks a lot Ingo! Here is the fixed changelog for 1/2 patch :Fix error interrupt report at all APs This patch fixes a bug reported from customer, who found many unreasonable error interrupts reported on all APs during the system boot stage. According to Chapter 10 of Intel Software Developer Manual Volume 3A, Local APIC may signal an illegal vector error when an LVT entry is set as an illegal vector value (0~15) under FIXED delivery mode (bits 8-11 is 0), regardless of whether the mask bit is set or an interrupt actually happen. These errors are seen as error interrupts. The initial value of thermal LVT entries on all APs always reads 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI sequence to them and LVT registers are reset to 0s except for the mask bits which are set to 1s when APs receive INIT IPI. When BIOS take over the thermal throttling interrupt, LVT thermal deliver mode should be SMI and it is required to restore AP's LVT thermal monitor register. This issue happens when BIOS do not take over thermal throttling interrupt, AP's LVT thermal monitor register will be restored to 0x10000 which means vector 0 and fixed deliver mode, so all APs will signal illegal vector error interrupt. This patch check if interrupt delivery mode is not fixed mode before restore AP's LVT thermal monitor register. -Youquan