From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752024AbdANJ7S (ORCPT ); Sat, 14 Jan 2017 04:59:18 -0500 Received: from terminus.zytor.com ([198.137.202.10]:47184 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751947AbdANJ7I (ORCPT ); Sat, 14 Jan 2017 04:59:08 -0500 Date: Sat, 14 Jan 2017 01:58:35 -0800 From: tip-bot for Len Brown Message-ID: Cc: torvalds@linux-foundation.org, len.brown@intel.com, hpa@zytor.com, peterz@infradead.org, tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org Reply-To: hpa@zytor.com, peterz@infradead.org, len.brown@intel.com, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, mingo@kernel.org, tglx@linutronix.de In-Reply-To: <306899f94804aece6d8fa8b4223ede3b48dbb59c.1484287748.git.len.brown@intel.com> References: <306899f94804aece6d8fa8b4223ede3b48dbb59c.1484287748.git.len.brown@intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/tsc: Add the Intel Denverton Processor to native_calibrate_tsc() Git-Commit-ID: 695085b4bc7603551db0b3da897b8bf9893ca218 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 695085b4bc7603551db0b3da897b8bf9893ca218 Gitweb: http://git.kernel.org/tip/695085b4bc7603551db0b3da897b8bf9893ca218 Author: Len Brown AuthorDate: Fri, 13 Jan 2017 01:11:18 -0500 Committer: Ingo Molnar CommitDate: Sat, 14 Jan 2017 09:30:37 +0100 x86/tsc: Add the Intel Denverton Processor to native_calibrate_tsc() 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 --- arch/x86/kernel/tsc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index be3a49e..e41af59 100644 --- 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: