2017-06-20 15:48 GMT+02:00 Alexandre Belloni <alexandre.bell...@free-electrons.com>: > On 20/06/2017 at 15:44:58 +0200, Pavel Machek wrote: >> 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.
What I had in mind when writing those patches was to remove the limitations coming from those functions usage, even more since they been marked has deprecated. I agree that will change nothing of hardware limitation but at least the limit will not come from the framework. >> > > Yes, we agree on that but I won't cherry pick working patches from a 51 > patches series. maybe only the acked ones ? > > > -- > Alexandre Belloni, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com
