Re: [PATCH 00/51] rtc: stop using rtc deprecated functions

From	Pavel Machek <pavel@ucw.cz>
Newsgroups	linux.kernel
Subject	Re: [PATCH 00/51] rtc: stop using rtc deprecated functions
Date	2017-06-20 15:50 +0200
Message-ID	<tUrHA-Q2-25@gated-at.bofh.it> (permalink)
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On Tue 2017-06-20 13:37:22, Steve Twiss wrote:
> Hi Pavel,
> 
> On 20 June 2017 14:26, Pavel Machek wrote:
> 
> > Subject: Re: [PATCH 00/51] rtc: stop using rtc deprecated functions
> > 
> > On Tue 2017-06-20 14:24:00, Alexandre Belloni wrote:
> > > On 20/06/2017 at 14:10:11 +0200, Pavel Machek wrote:
> > > > On Tue 2017-06-20 12:03:48, Alexandre Belloni wrote:
> > > > > On 20/06/2017 at 11:35:08 +0200, Benjamin Gaignard wrote:
> > > > > > rtc_time_to_tm() and rtc_tm_to_time() are deprecated because they
> > > > > > rely on 32bits variables and that will make rtc break in y2038/2016.
> > > > >
> > > > > Please don't, because this hide the fact that the hardware will not
> > > > > handle dates in y2038 anyway and as pointed by Russell a few month ago,
> > > > > rtc_time_to_tm will be able to catch it but the 64 bit version will
> > > > > silently ignore it.
> > > >
> > > > Reference? Because rtc on PCs stores date in binary coded decimal, so
> > > > it is likely to break in 2100, not 2038...
> > >
> > > I'm not saying it should be done but clearly, that is not the correct
> > > thing to do for RTCs that are using a single 32 bits register to store
> > > the time.
> > > You give one example, I can give you three: armada38x, at91sam9,
> > > at32ap700x and that just in the beginning of the series.
> > 
> > I wanted reference to Russell's mail.
> 
> This is it.
> https://patchwork.kernel.org/patch/6219401/

Thanks.

Yes, that's argument against changing rtc _drivers_ for hardware that
can not do better than 32bit. For generic code (such as 44/51 sysfs,
51/51 suspend test), the change still makes sense.

								Pavel

-- (english)
http://www.livejournal.com/~pavelmachek (cesky, pictures)
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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[PATCH 00/51] rtc: stop using rtc deprecated functions Benjamin Gaignard <benjamin.gaignard@linaro.org> - 2017-06-20 12:10 +0200
  [PATCH 02/51] x86: intel-mid: vrtc: stop using rtc deprecated functions Benjamin Gaignard <benjamin.gaignard@linaro.org> - 2017-06-20 12:10 +0200
  Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2017-06-20 12:10 +0200
  [PATCH 03/51] net: broadcom: stop using rtc deprecated functions Benjamin Gaignard <benjamin.gaignard@linaro.org> - 2017-06-20 12:10 +0200
  Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2017-06-20 12:10 +0200
    Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Pavel Machek <pavel@ucw.cz> - 2017-06-20 14:20 +0200
      Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2017-06-20 14:30 +0200
        Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Pavel Machek <pavel@ucw.cz> - 2017-06-20 15:30 +0200
          RE: [PATCH 00/51] rtc: stop using rtc deprecated functions Steve Twiss <stwiss.opensource@diasemi.com> - 2017-06-20 15:40 +0200
            Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2017-06-20 15:50 +0200
              Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Benjamin Gaignard <benjamin.gaignard@linaro.org> - 2017-06-20 17:10 +0200
                Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-06-20 23:20 +0200
                RE: [PATCH 00/51] rtc: stop using rtc deprecated functions David Laight <David.Laight@ACULAB.COM> - 2017-06-21 11:30 +0200
                Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-06-21 11:40 +0200
                Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Pavel Machek <pavel@ucw.cz> - 2017-06-21 00:10 +0200
                Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Benjamin Gaignard <benjamin.gaignard@linaro.org> - 2017-06-21 11:20 +0200
            Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Pavel Machek <pavel@ucw.cz> - 2017-06-20 15:50 +0200

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