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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 7DDF6C2D0CD for ; Wed, 18 Dec 2019 15:31:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53831206CB for ; Wed, 18 Dec 2019 15:31:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QAZz+nnY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727274AbfLRPbJ (ORCPT ); Wed, 18 Dec 2019 10:31:09 -0500 Received: from mail-pl1-f196.google.com ([209.85.214.196]:36743 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726955AbfLRPbJ (ORCPT ); Wed, 18 Dec 2019 10:31:09 -0500 Received: by mail-pl1-f196.google.com with SMTP id a6so388348plm.3; Wed, 18 Dec 2019 07:31:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=Y1KOP5OdhQQyB92O19ghP7GuEEOHhGyvDRkY0vdHulg=; b=QAZz+nnYo72dbTCkCYKr5WIrsUo2K+fi/czRJIuuWn4sHAe4/7jxOWuWLK6Vj59ElA Bbop+G46vyQA65gHtBQ/rH8svkHVJCVdAXYrTKHoQhsPt2eOKJhDZ0Zc+idnCn0+AM/F +kKDfboSZVJQI9IFr5KRLnVQy8/hc7SfCb3+wIKBFeWHbrD91dTACIRXmF020DvansIm K/xV+hmfaXij6SW1KQNuWeFBf7qpHZspmjqyLZCqvIME32Uf8SAcgGu48yKfZWfRoBVF T7eIz+xK6VA7mr5vRLQMm/Aw7gSvbYTQh8SBJo09AbPMhWdVW2lUjeB493Kdz8ErfAMg gubw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=Y1KOP5OdhQQyB92O19ghP7GuEEOHhGyvDRkY0vdHulg=; b=Ub0ViT48k/4v9rYQWaYhDYeOHgQK78shgWBPdXSDOL8Mcq9E5PACD9+B2xhlw4fkIc riUnv/uGzokVZJSlVrk1PXO7C0f+G7Fr7Yj7OSDJUDI9F90zm54PkdcvsA932JKCB3v9 gkzureM+XgW5vJlNe9PmEjgLsrNNH9cPYxlg741iAm2wd9ecbLT7vlOInppU/sZtJxtl dRs3+Xaedg9JG6o1Dzh0q3apLZX9mvgA+n0RGwitTA6fTUvNybeGMXFFr9eGlrgeiQ9s NRmaa/PX7lhG8kwPUD2RX802wKDku1ANVAs6JQDdIEFZ1EIdITg5HoRMfdWVeY/quOMB nyug== X-Gm-Message-State: APjAAAW5LxvRY1QI0ghIHPHUEn3fDl3IV36l4CcDvksBE2UEdG9Z7eHc px4FSEMJbykzfjk5UciliF/2fnPHMew= X-Google-Smtp-Source: APXvYqx+xl9RXuXsfmgBpWu8fE6Hhzu1qaJGCb9BuOaMuG6F3yvwAyGBOYMX+O8vtkjgeZhvgfjsWA== X-Received: by 2002:a17:90a:e28e:: with SMTP id d14mr3659378pjz.56.1576683068374; Wed, 18 Dec 2019 07:31:08 -0800 (PST) Received: from localhost.localdomain ([27.59.35.166]) by smtp.googlemail.com with ESMTPSA id j125sm3741982pfg.160.2019.12.18.07.31.05 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 18 Dec 2019 07:31:07 -0800 (PST) From: Vipul Kumar To: Daniel Lezcano , Thomas Gleixner Cc: , Stable , Srikanth Krishnakar , Cedric Hombourger , Vipul Kumar , Vipul Kumar Subject: [PATCH] x86/tsc: Unset TSC_KNOWN_FREQ and TSC_RELIABLE flags on Intel Bay Trail SoC Date: Wed, 18 Dec 2019 21:00:39 +0530 Message-Id: <1576683039-5311-1-git-send-email-vipulk0511@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vipul Kumar 'commit f3a02ecebed7 ("x86/tsc: Set TSC_KNOWN_FREQ and TSC_RELIABLE flags on Intel Atom SoCs")', causing time drift for Bay trail SoC. These flags are set for SoCs having cpuid_level 0x15 or more. Bay trail is having cpuid_level 0xb. So, unset both flags to make sure the clocksource calibration can be done. Signed-off-by: Vipul Kumar --- arch/x86/kernel/tsc_msr.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c index e0cbe4f2af49..1ca27c28db98 100644 --- a/arch/x86/kernel/tsc_msr.c +++ b/arch/x86/kernel/tsc_msr.c @@ -112,6 +112,9 @@ unsigned long cpu_khz_from_msr(void) lapic_timer_period = (freq * 1000) / HZ; #endif + if (boot_cpu_data.cpuid_level < 0x15) + return res; + /* * TSC frequency determined by MSR is always considered "known" * because it is reported by HW. -- 2.20.1