[ntp:questions] NTP not syncing

Jos van de Ven antispam at ven.ddns.net
Fri Dec 6 09:42:37 UTC 2013

Op 6 dec. 2013, om 09:47 heeft unruh <unruh at invalid.ca> het volgende geschreven:

> On 2013-12-06, David Taylor <david-taylor at blueyonder.co.uk.invalid> wrote:
>> On 04/12/2013 21:25, Terje Mathisen wrote:
>> []
>>> It is very common, IF you are running on Linux!
>>> The base frequency is recalculated each time you restart, which means
>>> that steps of 100-200 ppm from one reboot to the next can be expected.
>>> Terje
>> I'm surprised to hear of this problem, as I've not been aware of it in 
>> years of running FreeBSD systems, and in more than a year of running 
>> (now) five Raspberry Pi Linux systems.  Perhaps I've been lucky?  As 
>> they are mainly experimental PCs, the RPi cards are rebooted more than most.
> As I said, I think that in the more recent kernels Linux has fixed this.
> Since the RPi is only about 2 years old, its linux is a recent kernel. 



The Raspberry Pi does not ship with a TSC or HPET counter to use as clocksource. Instead it relies on the STC that raspbian presents as a clocksource. Based on the source code, "STC: a free running counter that increments at the rate of 1MHz".

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