From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750811AbWCVGT4 (ORCPT ); Wed, 22 Mar 2006 01:19:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750813AbWCVGT4 (ORCPT ); Wed, 22 Mar 2006 01:19:56 -0500 Received: from mail.gmx.de ([213.165.64.20]:29578 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S1750811AbWCVGTz (ORCPT ); Wed, 22 Mar 2006 01:19:55 -0500 X-Authenticated: #14349625 Subject: Re: p4-clockmod not working in 2.6.16 From: Mike Galbraith To: Edgar Toernig Cc: Dave Jones , linux-kernel@vger.kernel.org In-Reply-To: <20060322065714.169ce224.froese@gmx.de> References: <1142974528.3470.4.camel@localhost> <20060321210106.GA25370@redhat.com> <1142978230.3470.12.camel@localhost> <20060321220115.GA8583@redhat.com> <20060322065714.169ce224.froese@gmx.de> Content-Type: text/plain Date: Wed, 22 Mar 2006 07:20:05 +0100 Message-Id: <1143008405.13748.4.camel@homer> Mime-Version: 1.0 X-Mailer: Evolution 2.4.0 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2006-03-22 at 06:57 +0100, Edgar Toernig wrote: > And at last: reading Intel's errata it should be good enough to not go > below 25% instead limiting all below 2GHz. I'm not even sure whether > the 2GHz mentioned there is the reduced or the nominal clock. Running > 2GHz on 12.5% would be a really fast CPU. > > | N60. Processor May Hang under Certain Frequencies and 12.5% > | STPCLK# Duty Cycle > | > | Problem: If a system de-asserts STPCLK# at a 12.5% duty cycle, the > | processor is running below 2 GHz, and the processor thermal > | control circuit (TCC) on-demand clock modulation is active, > | the processor may hang. This erratum does not occur under > | the automatic mode of the TCC. > | > | Implication: When this erratum occurs, the processor will hang. > | > | Workaround: If use of the on-demand mode of the processor's TCC is desired > | in conjunction with STPCLK# modulation, then assure that STPCLK# > | is not asserted at a 12.5% duty cycle. Yeah, I read that too, and it looked to me like someone might have used a bit too mich blunt force. (not sure though) I disabled it so I could save a tree or two, and it seems to work fine. Of course, if it does ever have a seizure, I don't get to gripe ;-) -Mike