From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751779AbbHRCUT (ORCPT ); Mon, 17 Aug 2015 22:20:19 -0400 Received: from mga01.intel.com ([192.55.52.88]:2229 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751118AbbHRCUR (ORCPT ); Mon, 17 Aug 2015 22:20:17 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,698,1432623600"; d="scan'208";a="750529892" Message-ID: <55D2972C.3030709@intel.com> Date: Tue, 18 Aug 2015 10:23:40 +0800 From: Yu Chen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Pavel Machek , Ingo Molnar CC: rjw@rjwysocki.net, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, rui.zhang@intel.com, x86@kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86, suspend: Save/restore THERM_CONTROL register for suspend References: <1439800192-3034-1-git-send-email-yu.c.chen@intel.com> <20150817101115.GA27204@gmail.com> <20150817132726.GA11047@amd> In-Reply-To: <20150817132726.GA11047@amd> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Pavel, thanks for your review, On 08/17/2015 09:27 PM, Pavel Machek wrote: > On Mon 2015-08-17 12:11:15, Ingo Molnar wrote: >> >> * Chen Yu wrote: >> >>> A bug is reported(https://bugzilla.redhat.com/show_bug.cgi?id=1227208) > > Access denied :-( > Might need to register for accessing. > > What HW is this on? > Intel Braswell and Broadwell, detail for Broadwell: Platform: MayanCity Processor: 2x BROADWELL BDX_EP A0 QHPR Chipset: Wellsburg B1 QR7E > > - So BIOS expects to control MSR_IA32_THERM_CONTROL . Now you suspend > in hot enironment but resume in cool one. BIOS sets up > MSR_IA32_THERM_CONTROL the right way, but you override it. > > As BIOS expects to control MSR_IA32_THERM_CONTROL and machine is > kept cool, BIOS will not write new value to it, and machine will > keep running slowly. > Sorry, I can not quite catch up, do you mean we should let BIOS modifying MSR_IA32_THERM_CONTROL and leverage linux to adjust this value at runtime(after S3)? > Doing this unconditionally is asking for trouble. Blacklist entry with > affected BIOS info might be acceptable, but... > Pavel > you mean a quirk here(accroding to dmi info ,etc)? Best Regards, Yu