Subject: Re: todr changes to improve clock accuracy across sleeps &
To: Perry E. Metzger <email@example.com>
From: Richard Earnshaw <Richard.Earnshaw@buzzard.freeserve.co.uk>
Date: 09/07/2006 18:05:14
> It would be nice if, optionally, one could wait up to one second,
> spinning, for the RTC chip to turn over a fresh second before doing
> inittodr. Similarly, one would, optionally, wait up to one second
> before doing the resettodr -- that could be done with an interval
> timer controlled sleep since the system clock has high precision.
> I suggested making this optional (and possibly sysctlable) because
> some people won't care and will resent the one second additional
Why not leave the setting of the system clock as is (if you aren't on
line, then clock precision to within a second is just fine); and when
shutting down, don't write the RTC if it is within (say) 1 second of the
current time. This way you've preserved essentially all the accuracy of
your RTC without stalling at any point.