Date: Wed, 20 Nov 2019 22:56:24 -0700 From: Ian Lepore <ian@freebsd.org> To: ticso@cicely.de, freebsd-arm@freebsd.org Cc: Bernd Walter <ticso@cicely7.cicely.de> Subject: Re: 20h offset with DS3231 RTC Message-ID: <c05366074cc24e1894d90d8aa9861f2ab3baed0b.camel@freebsd.org> In-Reply-To: <20191120224239.GA34719@cicely7.cicely.de> References: <20191120224239.GA34719@cicely7.cicely.de>
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On Wed, 2019-11-20 at 23:42 +0100, Bernd Walter wrote: > I just added an RTC to a Pi3B with FreeBSD 12.1-RELEASE: > ds32310: <Maxim DS3231 RTC> at addr 0xd0 on iicbus0 > ... > Setting date via ntp. > 20 Nov 22:55:48 ntpdate[760]: step time server 46.165.221.137 offset > 71999.728041 sec > > This was the 3rd reboot. > The first boot had no actual time as expected and the RTC wasn't even > running. > The second already showed the offset. > > To verify I checked another systemm, wqhich I've added such an RTC > before. > dmesg said that it booted 9 days ago with 1s offset, but with another > reboot: > 20 Nov 23:31:44 ntpdate[826]: step time server 80.67.16.8 offset > 72000.160415 sec > > It seems that the error depends on the actual date/time. > I think this is because of a bug/lack-of-capability in the rpi i2c driver and/or hardware, and it affects all i2c devices that use some common driver routines to read and write slave device "registers". I'll look into fixing it, hopefully within a day. -- Ian
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