From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751042AbcFOEP5 (ORCPT ); Wed, 15 Jun 2016 00:15:57 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:48865 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750741AbcFOEP4 (ORCPT ); Wed, 15 Jun 2016 00:15:56 -0400 Subject: Re: [PATCH] rtc: ds1307: Fix relying on reset value for weekday To: Alexandre Belloni References: <1464778147-22075-1-git-send-email-j-keerthy@ti.com> <20160601121802.GF4249@piout.net> <574ED6D1.70800@ti.com> <575693E1.2090302@ti.com> <20160614143948.GP3240@piout.net> CC: Keerthy , , , , From: Keerthy Message-ID: <5760D631.1050006@ti.com> Date: Wed, 15 Jun 2016 09:44:41 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20160614143948.GP3240@piout.net> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 14 June 2016 08:09 PM, Alexandre Belloni wrote: > On 07/06/2016 at 14:59:05 +0530, Keerthy wrote : >> Hi Alexandre, >> >> On Wednesday 01 June 2016 06:06 PM, Keerthy wrote: >>> >>> >>> On Wednesday 01 June 2016 05:48 PM, Alexandre Belloni wrote: >>>> Hi, >>>> >>>> On 01/06/2016 at 16:19:07 +0530, Keerthy wrote : >>>>> The reset value of weekday is 0x1. This is wrong since >>>>> the reset values of the day/month/year make up to Jan 1 2001. >>>>> When computed weekday comes out to be Monday. On a scale >>>>> of 1-7(Sunday - Saturday) it should be 0x2. So we should not >>>>> be relying on the reset value. >>>>> >>>> >>>> Hum, what are the chances that the reset value is actually the correct >>>> date/time? >>>> Won't that be corrected after the first call to set_time? Until then, >>>> the date is not correct so, do we care anyway? >>> >>> Yes if an alarm is programmed without set_time. >>> >>> ex: rtcwake -d /dev/rtc0 -s 5 >>> >>> Even the basic rtctest under tools/testing/selftests/timers/rtctest.c fails >>> as the wday is wrong and no alarm fires. >>> >>> Instead of relying on some one to call set_time before programming alarm >>> its better to fix the wday to reflect the current day right? >>> >>> >>>> >>>> Maybe I'm missing something here. >> >> Let me know if you feel this is a valid fix. >> > > Well, this is probably a valid fix and I'll take it as is if I don't > find the time to make something more generic. Okay Thanks. >