From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: rtc-linux@googlegroups.com Received: from smtp.natisbad.org (36.223.133.77.rev.sfr.net. [77.133.223.36]) by gmr-mx.google.com with ESMTP id o85si1877283wme.0.2016.07.14.12.54.51 for ; Thu, 14 Jul 2016 12:54:51 -0700 (PDT) From: arno@natisbad.org (Arnaud Ebalard) To: Alexandre Belloni Cc: Alessandro Zummo , rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org Subject: [rtc-linux] Re: [PATCH] rtc: ds1307: fix century bit support References: <1468370064-19255-1-git-send-email-alexandre.belloni@free-electrons.com> Date: Thu, 14 Jul 2016 21:54:45 +0200 Message-ID: <87inw8hu62.fsf@natisbad.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Reply-To: rtc-linux@googlegroups.com List-ID: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , Hi Alexandre, Alexandre Belloni writes: > Add an option to properly support the century bit of ds1337 and compatibles > and ds1340. > Because the driver had a bug until now, it is not possible to switch users > to the fixed code directly as RTCs in the field will wrongly have the > century bit set. > > Signed-off-by: Alexandre Belloni > --- > > Arnaud, do you mind testing that patch, I still don't have the necessary > hardware but I think this is the proper course of action. I did some tests w/ all patches applied (the one below and the ones in the other series). I had to fix two errors: one pointed in the patch below and the other one in a patch in the other series (I'll reply to the patch). With both RTC_DRV_DS1307 and RTC_DRV_DS1307_CENTURY enabled, this works as expected on my side: booting on a system which had only seen an ISL12057 driver, the time on the system at boot (or via hwclock -r) is correct. Playing w/ -s and -w options works as expected. Booting back on a kernel w/ ISL12057 driver, things are also ok. So, AFAICT, your changes do the work. One small thing though: for user which have always used RTC_DRV_ISL12057 config knob, the change will not be transparent. Would it be possible to somehow make that old kernel config knob some kind of alias for RTC_DRV_DS1307 and RTC_DRV_DS1307_CENTURY in Kconfig? Cheers, a+ > +#ifdef CONFIG_RTC_DRV_DS1307_CENTURY > + switch (ds1307->type) { > + case ds_1337: > + case ds_1339: > + case ds_3231: > + if (ds1307->regs[DS1307_REG_MONTH] && DS1337_BIT_CENTURY) ^^ > + t->tm_year += 100; > + break; > + case ds_1340: > + if (ds1307->regs[DS1307_REG_HOUR] && DS1340_BIT_CENTURY) ^^ -- 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@googlegroups.com. For more options, visit https://groups.google.com/d/optout.