From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH][v5] x86, suspend: Save/restore extra MSR registers for suspend Date: Mon, 12 Oct 2015 21:15:44 +0200 Message-ID: <8500000.DY8G18orHR@vostro.rjw.lan> References: <1444533601-12330-1-git-send-email-yu.c.chen@intel.com> <20151012163750.GA4539@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20151012163750.GA4539@pd.tnic> Sender: linux-kernel-owner@vger.kernel.org To: Borislav Petkov Cc: Chen Yu , mingo@redhat.com, pavel@ucw.cz, tglx@linutronix.de, hpa@zytor.com, rui.zhang@intel.com, luto@kernel.org, linux@horizon.com, dsmythies@telus.net, linux-pm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, marcin.kaszewski@intel.com List-Id: linux-pm@vger.kernel.org On Monday, October 12, 2015 06:37:50 PM Borislav Petkov wrote: > On Sun, Oct 11, 2015 at 11:20:01AM +0800, Chen Yu wrote: > > A bug is reported(https://bugzilla.redhat.com/show_bug.cgi?id=1227208) > > I get: > > "You are not authorized to access bug #1227208. > > Most likely the bug has been restricted for internal development > processes and we cannot grant access." > > > that, after resumed from S3, CPU is running at a low speed. > > After investigation, it is found that, BIOS has modified the value > > of THERM_CONTROL register during S3, and changes it from 0 to 0x10 > > (thus changes the clock modulation from reserved to enabled), > > since value of 0x10 means CPU can only get 25% of the Duty Cycle, > > this triggers the problem. > > Is this what the bug described above is? In any case, please remove the > private bugzilla link and describe the bug in text here. > > Also, from reading the other thread about the v4 patch, it sounds like > intel_pstate can't handle the clock modulation properly, according to > what Doug says. > > So let's have this aspect sorted out properly first please before adding > yet another ugly BIOS workaround. > > Btw, why can't that BIOS be fixed instead? Because it's been shipped to users. Thanks, Rafael