Subject: Re: todr changes to improve clock accuracy across sleeps & reboots
To: Richard Earnshaw <Richard.Earnshaw@buzzard.freeserve.co.uk>
From: Perry E. Metzger <email@example.com>
Date: 09/07/2006 21:17:33
Richard Earnshaw <Richard.Earnshaw@buzzard.freeserve.co.uk> writes:
> 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.
The system clock is often being conditioned by something like NTP. The
reason for writing back the RTC when a change in the system clock
happens or another event that triggers resettodr is to assure that
they stay in sync so the next reboot gets the benefit of whatever is
conditioning the clock.