Clock drift on an iBook2

Ethan Blanton eblanton at
Wed Jul 18 03:04:25 EST 2001

Benjamin Herrenschmidt spake unto us the following wisdom:
> >I have a new iBook2 and I'm having *severe* clock drift problems -- on
> >the order of several seconds gained per minute.  I'd like to get this
> >taken care of, and it seems to be a linux problem as OSX appears to
> >have a stable clock.
> Are you using MOL or do you experience this with nothing special running ?

Nothing special...   I tried using ntpd to fix the problem, but it
didn't seem to be able to set the system time and I'm not sure why.

> Do you have the same issue if you disable powersave_nap (/proc/sys/
> kernel/powersave_nap) ?

Yes, it seems to make no difference.  (~4s of drift in 3 minutes
either way, according to the tests I just did)

> The TB is calibrated using the VIA, if we don't have a correct VIA frequency
> or if the calibration routine is slightly off, that may also explain the
> problem.

Looking into your next email regarding the VIA...

If I've told you once, I've told you once
And once is all that you needed.
		-- The Refreshments, "Carefree"

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