Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755848Ab0HaVKv (ORCPT ); Tue, 31 Aug 2010 17:10:51 -0400 Received: from mga03.intel.com ([143.182.124.21]:50521 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753970Ab0HaVKt (ORCPT ); Tue, 31 Aug 2010 17:10:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.56,300,1280732400"; d="scan'208";a="319342982" Date: Tue, 31 Aug 2010 14:01:13 -0700 From: Fenghua Yu To: Huaxu Wan Cc: Maxim Levitsky , "Yu, Fenghua" , "Wan, Huaxu" , "'linux-kernel@vger.kernel.org'" , "'lm-sensors@lm-sensors.org'" , "'khali@linux-fr.org'" Subject: Re: [PATCH 2/2] hwmon: (coretemp) Get TjMax value from MSR Message-ID: <20100831210113.GA30682@fenghua-desk.sc.intel.com> References: <20100507095945.GB12190@owl> <1275111551.3427.4.camel@maxim-laptop> <20100531013950.GA8265@owl> <1275496456.32562.4.camel@maxim-laptop> <1275509416.6277.2.camel@maxim-laptop> <1276347839.4481.22.camel@maxim-laptop> <625BA99ED14B2D499DC4E29D8138F1502C5405FCB0@shsmsx502.ccr.corp.intel.com> <1280132188.22558.0.camel@maxim-laptop> <1283132556.2159.9.camel@owl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1283132556.2159.9.camel@owl> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3249 Lines: 79 On Sun, Aug 29, 2010 at 06:42:36PM -0700, Huaxu Wan wrote: > On Mon, 2010-07-26 at 11:16 +0300, Maxim Levitsky wrote: > > On Sun, 2010-06-13 at 10:27 +0800, Wan, Huaxu wrote: > > > >On Wed, 2010-06-02 at 23:10 +0300, Maxim Levitsky wrote: > > > >> On Wed, 2010-06-02 at 19:34 +0300, Maxim Levitsky wrote: > > > >> > On Mon, 2010-05-31 at 09:39 +0800, Huaxu Wan wrote: > > > >> > > On 08:39 Sat 29 May, Maxim Levitsky wrote: > > > >> > > > On Fri, 2010-05-07 at 17:59 +0800, Huaxu Wan wrote: > > > >> > > > > The MSR IA32_TEMPERATURE_TARGET contains the TjMax > > > >value in the newer > > > >> > > > > processers. > > > >> > > > > > > >> > > > I know that TjMax on my system is 85, and now coretemp > > > >reports wrong > > > >> > > > temperatures. > > > >> > > > First of all BIOS using stupid tricks actualy reports > > > >CPU temperature > > > >> > > > through ACPI, and assuming it was correct TjMax is 85. > > > >> > > > It also shuts down the system if I 'lie' to it that > > > >cpu temperature is > > > >> > > > 85C. > > > >> > > > > > >> > > From the list at [1], the TjMax(Tjunction) of T5450 is > > > >100C. Does anyone > > > >> > > here can make a double check? > > > >> > > > > > >> > > [1] > > > >http://ark.intel.com/Product.aspx?id=30787&processor=T5450&spec > > > >-codes=SLA4F > > > >> > > > > >> > This is very interesting. > > > >> > > > > >> > With TjMax 85C, the CPUs idle temperature is reported at > > > >around 45~50C > > > >> > GPU temperature that is around 50C > > > >> > > > > >> > BIOS also reports 45~50C. > > > >> > > > > >> > BIOS hooks an SMI to CPU thermal report, and stores the > > > >temperature it > > > >> > read in ram, then ACPI code reads it, reports and passes to the EC > > > >> > (embedded controller). > > > >> > > > > >> > If I write myself 85 to embedded controller, systems shuts down. > > > >> > (values less that 85, eg 84 don't shut system). > > > >> > > > >> > > > >> Another clue is that right after resume from ram, after long delay > > > >> (~hour) the displayed temperature with TjMax 85 is 33C. Since room > > > >> temperature here is around 27C, this seems more plausible that > > > >> 33 + 15 = 48C > > > > > > > > > > > >Any update? > > > > > > I'm occupied by other things, sorry for slow response. But, as said in a > > > spec, I can't remember which one now, there are too many, the relative > > > value read from DTS is accurate approaching to TjMax. The accuracy > > > deteriorates to +-10C at 50C. Any DTS reading below 50C should be > > > considered to indicate only a temperature below 50C and not a specific > > > temperature. > > > > > > So, the value around 50C can't be taken as real chip temperature. I > > > would like this issue could be confirmed by more users to avoid it as a > > > particular case. At the meantime, I still looking for a laptop with T5450, > > > this may take some time. Hi, Maxim, Could you send out thermal zone info under /proc/acpi/thermal_zone/TZ*? Thanks. -Fenghua -- 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/