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=ham 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 DAA6DC2BB85 for ; Thu, 9 Apr 2020 20:46:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFB3920730 for ; Thu, 9 Apr 2020 20:46:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="vTO45h5q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727184AbgDIUqT (ORCPT ); Thu, 9 Apr 2020 16:46:19 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:46895 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726725AbgDIUqT (ORCPT ); Thu, 9 Apr 2020 16:46:19 -0400 Received: by mail-wr1-f67.google.com with SMTP id f13so7009352wrm.13 for ; Thu, 09 Apr 2020 13:46:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=lD1Rt/y2uoNW+nfIN7RZ4aTdLWF/Ni9UbL6zK1y9lCs=; b=vTO45h5qjxpUO0RZop+vt4zHCddVEsZg/knGJrQn7U+9DGy67NQQXrh5TsjLyQKFxk SVJ4ctNyC2RjMmwReBBiXEmv8qAjR3Axw/byAo3Pj/w49nw5+YMtL7twgpeAPoGbZCXz 0M02Fe5dDpE5jg4qlkoUgpj0CcHSn0dZMW+4a9LjQ08lCk/CqL7jcpvzC/MgKDixMzXI zhXzxMDFp9Sh8EKc30sXOVpooFDSWETY3fGnVyR4YswQIh47peeB/Dk0Dl0CGxVXN59v Bk9e5sMiVdKHPKW3NqBcvwElouV/WMgTem0s+CQZIvqdiBLGHj72A9ZM9/VBArivHXP3 vIuQ== 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:mime-version :content-transfer-encoding; bh=lD1Rt/y2uoNW+nfIN7RZ4aTdLWF/Ni9UbL6zK1y9lCs=; b=SJWtuAsJVxKYeUnRgmZeR+zaLivvm+58GVsKH5WOCyx68XuvdE/xeBo/wZFoKFKrxp OLRWyvRGc9HUtJq5JqUHd5rhxWXTFN/ljlTO5EVg2nOxvr0ZrdtrOsoqx5JiX20TxJlQ 3dVj0qA6Agt3UnX7UGNqC2IULAM3QDODCGULo2eYrwtDGaxsuPx7y5lDbIyOwfoWhiuA nutZTHXJaujRUSNdT2/2uud/Q5cAbQGU6VoUa+yUpC1fU4dqnSTYGmD8jQh+hVhD/XV9 zacqFqvh5cUlEX2P0fH7nHv2pf0iwSy4OeHkIG7rk3gIkmmi1uq7YBzbSqkvBq2y3tYd QOXg== X-Gm-Message-State: AGi0PuZPeYUtXHu1u/hXTSI7mVl8Hkm6/Uq+7huI8ABYuoHePc+LZjiB UMiqI1viS/HD9wrFh8qsSdC2Xak3jJY= X-Google-Smtp-Source: APiQypLKK0n4RrvpfsZv9DWiFKMNRxBOXEgwdl/5+7rT+wUMjrtPZmlVoDQbKd2WnWBKMbZfIRzE8w== X-Received: by 2002:a5d:5228:: with SMTP id i8mr1038315wra.156.1586465176507; Thu, 09 Apr 2020 13:46:16 -0700 (PDT) Received: from localhost.localdomain ([89.208.134.182]) by smtp.gmail.com with ESMTPSA id c18sm40639876wrx.5.2020.04.09.13.46.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Apr 2020 13:46:15 -0700 (PDT) From: Leonid Bloch To: linux-kernel@vger.kernel.org Cc: John Stultz , Thomas Gleixner , Stephen Boyd , Leonid Bloch Subject: [PATCH] rtc: Do not sync CMOS clock when CONFIG_RTC_SYSTOHC is not set Date: Thu, 9 Apr 2020 23:46:07 +0300 Message-Id: <20200409204607.8280-1-lb.workbox@gmail.com> X-Mailer: git-send-email 2.26.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org According to documentation in 'drivers/rtc/Kconfig', if 'CONFIG_RTC_SYSTOHC' is set, then: ''' The system time (wall clock) will be stored in the RTC specified by RTC_HCTOSYS_DEVICE approximately every 11 minutes if userspace reports synchronized NTP status. ''' However in reality, even if 'CONFIG_RTC_SYSTOHC' is not set, the RTC is still sometimes synced with the system time: at least when the RTC driver is 'rtc_cmos', in certain situations. This commit prevents that. Signed-off-by: Leonid Bloch --- kernel/time/ntp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 069ca78fb0bf..58260ca75c64 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -535,9 +535,6 @@ static void sync_rtc_clock(void) struct timespec64 adjust, now; int rc; - if (!IS_ENABLED(CONFIG_RTC_SYSTOHC)) - return; - ktime_get_real_ts64(&now); adjust = now; @@ -613,6 +610,9 @@ static bool sync_cmos_clock(void) */ static void sync_hw_clock(struct work_struct *work) { + if (!IS_ENABLED(CONFIG_RTC_SYSTOHC)) + return; + if (!ntp_synced()) return; -- 2.26.0