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SubjectRe: RTC subsystem and fractions of seconds
On Fri, Jan 05, 2007 at 07:49:00PM -0800, David Brownell wrote:
> > Those rtc's actually have a 1/100th of second
> > register. Should the generic rtc interface not support that?
>
> Are you implying a new userspace API, or just an in-kernel update?

My only concern at the moment is initializing linux's timeofday from the rtc
quickly and with a good precision. The way it is done currently
in drivers/rtc/hctosys.c is 0.5 sec off. We could obtain a much better
precision by looping there until the next change (next second for old clocks,
next 0.01 second for m41t81, maybe even better for other ones).

>
> Either way, that raises the question of what other features should
> be included. What sub-second precision? Multiple alarms? Ways
> to manage output clocks? Sub-HZ periodic alarms?

I cannot answer that, but others may have other needs.

Philippe
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