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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 4A781C35240 for ; Wed, 29 Jan 2020 15:14:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2233220716 for ; Wed, 29 Jan 2020 15:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726858AbgA2POD (ORCPT ); Wed, 29 Jan 2020 10:14:03 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:51538 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726358AbgA2POD (ORCPT ); Wed, 29 Jan 2020 10:14:03 -0500 Received: from 80-254-69-18.dynamic.monzoon.net ([80.254.69.18] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iwp2H-0002On-8y; Wed, 29 Jan 2020 16:13:45 +0100 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id DBEFC105CFD; Wed, 29 Jan 2020 16:13:39 +0100 (CET) From: Thomas Gleixner To: Hans de Goede , Andy Shevchenko Cc: vipul kumar , Daniel Lezcano , linux-kernel@vger.kernel.org, Stable , Srikanth Krishnakar , Cedric Hombourger , x86@kernel.org, Len Brown , Vipul Kumar Subject: Re: [v3] x86/tsc: Unset TSC_KNOWN_FREQ and TSC_RELIABLE flags on Intel Bay Trail SoC In-Reply-To: <91cdda7a-4194-ebe7-225d-854447b0436e@redhat.com> References: <20200123144108.GU32742@smile.fi.intel.com> <87iml11ccf.fsf@nanos.tec.linutronix.de> <87ftg5131x.fsf@nanos.tec.linutronix.de> <30d49be8-67ad-6f32-37a8-0cdd26f0852e@redhat.com> <87sgjz434v.fsf@nanos.tec.linutronix.de> <20200129130350.GD32742@smile.fi.intel.com> <0d361322-87aa-af48-492c-e8c4983bb35b@redhat.com> <20200129141444.GE32742@smile.fi.intel.com> <91cdda7a-4194-ebe7-225d-854447b0436e@redhat.com> Date: Wed, 29 Jan 2020 16:13:39 +0100 Message-ID: <87imku2t3w.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hans de Goede writes: > On 29-01-2020 15:14, Andy Shevchenko wrote: >>> The only one which is possibly suspicious here is this line: >>> >>> * 0111: 25 * 32 / 9 = 88.8889 MHz >>> >>> The SDM says 88.9 MHz for this one. I trust math more than the SDM :) >> Anyway it seems need to be fixed as well. >> >> Btw, why we are mentioning 20 / 6 and 28 / 6 when arithmetically >> it's the same as 10 / 3 and 14 / 3? > > I copied the BYT values from Thomas' email and I guess he did not > get around to simplifying them, I'll use the simplified versions > for my patch. Too tired, too lazy :) Andy, can you please make sure that people inside Intel who can look into the secrit documentation confirm what we are aiming for? Ideally they should provide the X-tal frequency and the mult/div pair themself :) Thanks, tglx