RTC drift on Walnut?

Torben Mathiasen torben at kernel.dk
Tue Jul 10 02:17:20 EST 2001


tn Mon, Jul 09 2001, akuster at mvista.com wrote:
> Torben Mathiasen wrote:
> >
> > Hi,
> >
> > I'm seeing a rather large drift of the RTC on a Walnut system. I haven't
> > got the exact numbers, but its something like 20mins in 24 hours.
> > This is with the montavista 2.4.2 kernel.
> >
> > Has anyone seen this before?
> >
> > Thanks in advance,
> >
> > Torben
> >
>
> Torben;
>
> I am not sure.  I will have to check, I will let you know tomorrow.

Thanks. I'm pretty sure its kernel related, I bet something's wrong in
arch/ppc/kernel/time.c. The kernel just reads the RTC at startup, and maintains
the system clok via the timer-interrupts. Coming to think of it, I'm not sure
if the hardware RTC drifts, or if its just the kernel 'software' clock. Will
check on that.

Maybe we're turning ints off for too long somewhere...

Thanks,
Torben

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