Re: [RFC PATCH 0/5] Add support for S3 non-stop TSC support.

From: Pavel Machek
Date: Sat Mar 30 2013 - 14:14:57 EST


Hi!

> >On some new Intel Atom processors (Penwell and Cloverview), there is
> >a feature that the TSC won't stop S3, say the TSC value won't be
> >reset to 0 after resume. This feature makes TSC a more reliable
> >clocksource and could benefit the timekeeping code during system
> >suspend/resume cycles.
> >
> >The enabling efforts include adding new flags for this feature,
> >modifying clocksource.c and timekeeping.c to support and utilizing
> >it.
> >
> >One remaining question is inside the timekeeping_resume(), we don't
> >know if it is called by resuming from suspend(s2ram) or from
> >hibernate(s2disk), as there is no easy way to check it currently.
> >But it doesn't hurt as these Penwell/Cloverview platforms only have
> >S3 state, and no S4.
> >
> >Please help to review them, thanks!
>
> The patches look reasonable to me.

Not sure... what are advantages? TSC is high resolution, but not
exactly precise time source... and this only makes resume more
complex.

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/