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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 034FBC433F5 for ; Sun, 7 Nov 2021 22:55:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE3836139E for ; Sun, 7 Nov 2021 22:55:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236695AbhKGW5r (ORCPT ); Sun, 7 Nov 2021 17:57:47 -0500 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:54461 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233191AbhKGW5r (ORCPT ); Sun, 7 Nov 2021 17:57:47 -0500 Received: (Authenticated sender: alexandre.belloni@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 25BAF20008; Sun, 7 Nov 2021 22:55:01 +0000 (UTC) From: Alexandre Belloni To: Alessandro Zummo , Alexandre Belloni Cc: linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 01/12] rtc: handle alarms with a minute resolution Date: Sun, 7 Nov 2021 23:54:46 +0100 Message-Id: <20211107225458.111068-1-alexandre.belloni@bootlin.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org Handle alarms with a minute resolution in the core. Until now drivers have been open coding the seconds part removal and have been doing that wrongly. Most of them are rounding up which means the allow the system to miss deadlines. So, round down and let __rtc_set_alarm return immediately if the time has already passed. Signed-off-by: Alexandre Belloni --- drivers/rtc/interface.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index d005623e6eb3..d8e835798153 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -423,6 +423,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) if (err) return err; now = rtc_tm_to_time64(&tm); + if (scheduled <= now) return -ETIME; /* @@ -447,6 +448,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { + ktime_t alarm_time; int err; if (!rtc->ops) @@ -468,7 +470,15 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) if (rtc->aie_timer.enabled) rtc_timer_remove(rtc, &rtc->aie_timer); - rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); + alarm_time = rtc_tm_to_ktime(alarm->time); + /* + * Round down so we never miss a deadline, checking for past deadline is + * done in __rtc_set_alarm + */ + if (test_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features)) + alarm_time = ktime_sub_ns(alarm_time, (u64)alarm->time.tm_sec * NSEC_PER_SEC); + + rtc->aie_timer.node.expires = alarm_time; rtc->aie_timer.period = 0; if (alarm->enabled) err = rtc_timer_enqueue(rtc, &rtc->aie_timer); -- 2.31.1