Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755845AbdGCOWu (ORCPT ); Mon, 3 Jul 2017 10:22:50 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36624 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932825AbdGCNom (ORCPT ); Mon, 3 Jul 2017 09:44:42 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Len Brown , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Sasha Levin Subject: [PATCH 4.9 116/172] x86/tsc: Add the Intel Denverton Processor to native_calibrate_tsc() Date: Mon, 3 Jul 2017 15:34:56 +0200 Message-Id: <20170703133419.719251881@linuxfoundation.org> X-Mailer: git-send-email 2.13.2 In-Reply-To: <20170703133414.260777365@linuxfoundation.org> References: <20170703133414.260777365@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1306 Lines: 40 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Len Brown [ Upstream commit 695085b4bc7603551db0b3da897b8bf9893ca218 ] The Intel Denverton microserver uses a 25 MHz TSC crystal, so we can derive its exact [*] TSC frequency using CPUID and some arithmetic, eg.: TSC: 1800 MHz (25000000 Hz * 216 / 3 / 1000000) [*] 'exact' is only as good as the crystal, which should be +/- 20ppm Signed-off-by: Len Brown Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/306899f94804aece6d8fa8b4223ede3b48dbb59c.1484287748.git.len.brown@intel.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/tsc.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -694,6 +694,7 @@ unsigned long native_calibrate_tsc(void) crystal_khz = 24000; /* 24.0 MHz */ break; case INTEL_FAM6_SKYLAKE_X: + case INTEL_FAM6_ATOM_DENVERTON: crystal_khz = 25000; /* 25.0 MHz */ break; case INTEL_FAM6_ATOM_GOLDMONT: