From mboxrd@z Thu Jan 1 00:00:00 1970 From: pavel@ucw.cz (Pavel Machek) Date: Wed, 21 Jun 2017 09:51:52 +0200 Subject: [PATCH 00/51] rtc: stop using rtc deprecated functions In-Reply-To: References: <20170620213507.urobmtg34vzubrdq@piout.net> Message-ID: <20170621075152.GA15996@amd> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 181 bytes Desc: Digital signature URL: