From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH 00/51] rtc: stop using rtc deprecated functions Date: Wed, 21 Jun 2017 09:51:52 +0200 Message-ID: <20170621075152.GA15996@amd> References: <20170620213507.urobmtg34vzubrdq@piout.net> Reply-To: rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="3MwIy2ne0vdjdPXF" Cc: Alexandre Belloni , Russell King - ARM Linux , Benjamin Gaignard , Baruch Siach , "patches-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org" , Linus Walleij , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Thierry Reding , "x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , Jonathan Hunter , Chen-Yu Tsai , Ingo Molnar , Sylvain Lemieux , Sebastian Hesselbarth , Len Brown , "linaro-kernel-cunTk1MwBs8s++Sfvej+rw@public.gmane.org" , Jason Cooper , "rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org" , "linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" Return-path: Sender: rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Content-Disposition: inline In-Reply-To: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , List-Id: netdev.vger.kernel.org --3MwIy2ne0vdjdPXF Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Hi! > > I agree with that but not the android guys. They seem to mandate an RTC > > that can store time from 01/01/1970. I don't know much more than that > > because they never cared to explain why that was actually necessary > > (apart from a laconic "this will result in a bad user experience") > > > > I think tglx had a plan for offsetting the time at some point so 32-bit > > platform can pass 2038 properly. > > Yes, but there are still quite some issues to solve there: > > 1) How do you tell the system that it should apply the offset in the > first place, i.e at boot time before NTP or any other mechanism can > correct it? I'd not do offset. Instead, I'd select a threshold (perhaps year of release of given kernel?) and if (rtc_time < year_of_release_of_kernel) rtc_time += 0x100000000; Ok, we'll have to move away from "rtc_time == 0 indicates zero", as seen in some drivers. > 2) Deal with creative vendors who have their own idea about the 'start > of the epoch' If someone uses different threshold, well, there will be confusion. But only for users that have their rtc set to the past, which is quite unusual. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- You received this message because you are subscribed to "rtc-linux". Membership options at http://groups.google.com/group/rtc-linux . Please read http://groups.google.com/group/rtc-linux/web/checklist before submitting a driver. --- You received this message because you are subscribed to the Google Groups "rtc-linux" group. To unsubscribe from this group and stop receiving emails from it, send an email to rtc-linux+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit https://groups.google.com/d/optout. --3MwIy2ne0vdjdPXF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAllKJZgACgkQMOfwapXb+vKcSACeKjx9YgZ8vE/6kkH+mZDPeoMx BPIAnRnqcPYJuL+92glv1bkWRQ7bPmio =FHDU -----END PGP SIGNATURE----- --3MwIy2ne0vdjdPXF--