From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26E00C3A5A1 for ; Wed, 28 Aug 2019 08:50:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 03FD92189D for ; Wed, 28 Aug 2019 08:50:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726561AbfH1Iua (ORCPT ); Wed, 28 Aug 2019 04:50:30 -0400 Received: from mga11.intel.com ([192.55.52.93]:20784 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726232AbfH1Iu3 (ORCPT ); Wed, 28 Aug 2019 04:50:29 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Aug 2019 01:50:28 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,440,1559545200"; d="scan'208";a="171472029" Received: from chenyu-office.sh.intel.com ([10.239.158.163]) by orsmga007.jf.intel.com with ESMTP; 28 Aug 2019 01:50:27 -0700 Date: Wed, 28 Aug 2019 17:00:44 +0800 From: Yu Chen To: Greg KH Cc: Sasha Levin , linux-kernel@vger.kernel.org, stable-commits@vger.kernel.org Subject: Re: Patch "x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume" has been added to the 4.4-stable tree Message-ID: <20190828090043.GA7589@chenyu-office.sh.intel.com> References: <20190828041240.12F5221883@mail.kernel.org> <20190828084351.GC29927@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190828084351.GC29927@kroah.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 28, 2019 at 10:43:51AM +0200, Greg KH wrote: > On Wed, Aug 28, 2019 at 12:12:39AM -0400, Sasha Levin wrote: > > This is a note to let you know that I've just added the patch titled > > > > x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume > > > > to the 4.4-stable tree which can be found at: > > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary > > > > The filename of the patch is: > > x86-pm-introduce-quirk-framework-to-save-restore-ext.patch > > and it can be found in the queue-4.4 subdirectory. > > > > If you, or anyone else, feels it should not be added to the stable tree, > > please let know about it. > > > > > > > > commit d63273440aa0fdebc30d0c931f15f79beb213134 > > Author: Chen Yu > > Date: Wed Nov 25 01:03:41 2015 +0800 > > > > x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume > > > > A bug was reported that on certain Broadwell platforms, after > > resuming from S3, the CPU is running at an anomalously low > > speed. > > > > It turns out that the BIOS has modified the value of the > > THERM_CONTROL register during S3, and changed it from 0 to 0x10, > > thus enabled clock modulation(bit4), but with undefined CPU Duty > > Cycle(bit1:3) - which causes the problem. > > > > Here is a simple scenario to reproduce the issue: > > > > 1. Boot up the system > > 2. Get MSR 0x19a, it should be 0 > > 3. Put the system into sleep, then wake it up > > 4. Get MSR 0x19a, it shows 0x10, while it should be 0 > > > > Although some BIOSen want to change the CPU Duty Cycle during > > S3, in our case we don't want the BIOS to do any modification. > > > > Fix this issue by introducing a more generic x86 framework to > > save/restore specified MSR registers(THERM_CONTROL in this case) > > for suspend/resume. This allows us to fix similar bugs in a much > > simpler way in the future. > > > > When the kernel wants to protect certain MSRs during suspending, > > we simply add a quirk entry in msr_save_dmi_table, and customize > > the MSR registers inside the quirk callback, for example: > > > > u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; > > > > and the quirk mechanism ensures that, once resumed from suspend, > > the MSRs indicated by these IDs will be restored to their > > original, pre-suspend values. > > > > Since both 64-bit and 32-bit kernels are affected, this patch > > covers the common 64/32-bit suspend/resume code path. And > > because the MSRs specified by the user might not be available or > > readable in any situation, we use rdmsrl_safe() to safely save > > these MSRs. > > > > Reported-and-tested-by: Marcin Kaszewski > > Signed-off-by: Chen Yu > > Acked-by: Rafael J. Wysocki > > Acked-by: Pavel Machek > > Cc: Andy Lutomirski > > Cc: Borislav Petkov > > Cc: Brian Gerst > > Cc: Denys Vlasenko > > Cc: H. Peter Anvin > > Cc: Linus Torvalds > > Cc: Peter Zijlstra > > Cc: Thomas Gleixner > > Cc: bp@suse.de > > Cc: len.brown@intel.com > > Cc: linux@horizon.com > > Cc: luto@kernel.org > > Cc: rjw@rjwysocki.net > > Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com > > [ More edits to the naming of data structures. ] > > Signed-off-by: Ingo Molnar > > No git id of the patch in Linus's tree, or your signed-off-by? > I think the commit id in Linus'tree should be 7a9c2dd08eadd5c6943115dbbec040c38d2e0822 Thanks, Chenyu > Sasha, did your scripts trigger this unintentionally somehow? > > thanks, > > greg k-h