From: Keerthy <a0393675@ti.com>
To: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Keerthy <j-keerthy@ti.com>, <a.zummo@towertech.it>, <nm@ti.com>,
<rtc-linux@googlegroups.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] rtc: ds1307: Fix relying on reset value for weekday
Date: Wed, 15 Jun 2016 09:44:41 +0530 [thread overview]
Message-ID: <5760D631.1050006@ti.com> (raw)
In-Reply-To: <20160614143948.GP3240@piout.net>
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.
>
next prev parent reply other threads:[~2016-06-15 4:15 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-01 10:49 [PATCH] rtc: ds1307: Fix relying on reset value for weekday Keerthy
2016-06-01 12:18 ` Alexandre Belloni
2016-06-01 12:36 ` Keerthy
2016-06-07 9:29 ` Keerthy
2016-06-14 14:39 ` Alexandre Belloni
2016-06-15 4:14 ` Keerthy [this message]
2016-07-08 14:25 ` Alexandre Belloni
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