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 5916CC55186 for ; Sun, 26 Apr 2020 01:35:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2698520706 for ; Sun, 26 Apr 2020 01:35:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="geKeVi1E" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726110AbgDZBfg (ORCPT ); Sat, 25 Apr 2020 21:35:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725931AbgDZBff (ORCPT ); Sat, 25 Apr 2020 21:35:35 -0400 Received: from mail-wm1-x343.google.com (mail-wm1-x343.google.com [IPv6:2a00:1450:4864:20::343]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A203C061A0C for ; Sat, 25 Apr 2020 18:35:35 -0700 (PDT) Received: by mail-wm1-x343.google.com with SMTP id 188so15598620wmc.2 for ; Sat, 25 Apr 2020 18:35:35 -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=zMJDJfeA5eXVGIqjbISZ5/ttz+CXriZ4CrIpCaO+pAs=; b=geKeVi1ESc3wgnvG5vOZQFy9X/ZWBsQpQi1t9jZr9fa0vHFfkz6AWIrjqd3uLqmbxs RhWMBBY26+jaaOpEjXO3cVWxGnX/o0uJ6ZHIw8Mw5eiolk6OkaHJ8t4oFj3K/jiJdgc3 fEnHYvia3Bqhj/CuJIFSJGRjwD5vtyAXP/MdZZzWVo7U3/UNXPwgTeviTxr3MUPzMTBy yMj36e94EeDUQg3heg7Ms4UM0bMhIiMBYV0opZFSeCYApmTPmCy0w82bwyPwmZwHoBoV 5ImB4NvrgtxXbN36xhVEE8haLDx4SfgRIaMa9eFRAbiohkkG0IcPP1ZUhfIlNBuy4yPF n10g== 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=zMJDJfeA5eXVGIqjbISZ5/ttz+CXriZ4CrIpCaO+pAs=; b=r80njAac7MTeIlHc51nLzHRd0hBr3YB6PhxjZUOnRg02B664mjYtBXC5u4cblSYaiu TlmvEluERgxyzQXBvCog2OZtuE4hlfJ5Lj3RHJ9tZcKWX7Uwr4UBEkJC9wDejB7u04vH prw6TisXfDOjaK+Q2Vh2TNNqLkoJW9yslZJZBH/LJMipqcaBIOwFu6ELV26FMpHqAuUu pnAq1IUdTg4tyxv2mj0msrxr1eVjssekZIUZcqEipLGlnzj9Ay1/sDm1oTohmJt6yOG5 jATu8dKjN5UA4wIXPq8DCydGrFpGJ2VwdX3vvAcFNGzdOwXt1Ew6PTJqO6ttOe6A8r7d 5nnw== X-Gm-Message-State: AGi0Puafj5VTpQ7XC9NkGsOcjjAwDlGNTsSMqbmJDGyZiNwXzyE+GQPg r8PXOl6kQp/B6FDqVOT9vBfVKnBE/+p0eQ== X-Google-Smtp-Source: APiQypJE7SFdAWoHbLgBRL511YDWby4053psGjZArCo2Zm03OZhAKVCRp5Bv1FwWzBHL5Am8ZDx6XA== X-Received: by 2002:a05:600c:441a:: with SMTP id u26mr19757889wmn.154.1587864933945; Sat, 25 Apr 2020 18:35:33 -0700 (PDT) Received: from localhost.localdomain ([89.208.134.182]) by smtp.gmail.com with ESMTPSA id e13sm5482885wrp.15.2020.04.25.18.35.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 25 Apr 2020 18:35:33 -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: Sun, 26 Apr 2020 04:35:21 +0300 Message-Id: <20200426013521.43087-1-lb.workbox@gmail.com> X-Mailer: git-send-email 2.26.2 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; -- 2.26.2