Re: [PATCH] rtc: ds1307: Fix relying on reset value for weekday

From	Keerthy <a0393675@ti.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] rtc: ds1307: Fix relying on reset value for weekday
Date	2016-06-15 06:20 +0200
Message-ID	<rKat3-5ZK-3@gated-at.bofh.it> (permalink)
References	<rFc2u-7m8-23@gated-at.bofh.it> <rFdhT-8iE-17@gated-at.bofh.it> <rFdBg-8pl-19@gated-at.bofh.it> <rHlEm-Wz-13@gated-at.bofh.it> <rJXPd-66e-49@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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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.

>

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Re: [PATCH] rtc: ds1307: Fix relying on reset value for weekday Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-06-14 16:50 +0200
  Re: [PATCH] rtc: ds1307: Fix relying on reset value for weekday Keerthy <a0393675@ti.com> - 2016-06-15 06:20 +0200

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