Thanks. I'm not precisely sure of the terminology, but the BeagleBone decides that the 'clocksource' is 24mHz. Its RTC will then gain *exactly* two minutes every 24 minutes if you disable timesyncd. With pullup resistors it will decide that the clocksource is 26mHz and the RTC will be virtually perfect:
debian@arm:~$ dmesg | grep -i timer [ 0.000000] OMAP clockevent source: timer2 at 26000000 Hz [ 0.000029] clocksource: timer1: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 73510017198 ns [ 0.000039] OMAP clocksource: timer1 at 26000000 Hz [ 0.000568] timer_probe: no matching timers found [ 0.463409] clocksource: Switched to clocksource timer1 The custom cape leaves the 'boot pins' floating (unless I add the pullups), and I get the same behavior with the BeagleBone running by itself with no cape. On Wednesday, January 16, 2019 at 5:15:24 PM UTC-5, Graham wrote: > > The standard external clock frequency source for the BeagleBone Black is > 24 MHz. > > Is that what you are referring to? > > Are you protecting all the "Boot Pins", so that your "Custom Cape" is not > overriding the boot programming resistors on the BBB? > > --- Graham > > On Wednesday, January 16, 2019 at 3:25:48 PM UTC-6, pbft wrote: >> >> Quick update: I've built 4.18.20 from source, and it has the same >> behavior. >> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/040ea632-065a-4332-801a-794df698384b%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
