Messages in this thread | | | Date | Wed, 18 Sep 2013 00:25:02 +0200 | From | Marc Kleine-Budde <> | Subject | Re: [PATCH] clockevents: Sanitize ticks to nsec conversion |
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On 09/17/2013 11:15 PM, Thomas Gleixner wrote: > Marc Kleine-Budde pointed out, that commit 77cc982 "clocksource: use > clockevents_config_and_register() where possible" caused a regression > for some of the converted subarchs. > > The reason is, that the clockevents core code converts the minimal > hardware tick delta to a nanosecond value for core internal > usage. This conversion is affected by integer math rounding loss, so > the backwards conversion to hardware ticks will likely result in a > value which is less than the configured hardware limitation. The > affected subarchs used their own workaround (SIGH!) which got lost in > the conversion. > > Now instead of fixing the underlying core code problem, Marcs patch > tried to work around the core code issue by increasing the minimal > tick delta at clockevents registration time so the resulting limit in > the core code backwards conversion did not violate the hardware > limits. More SIGH!
It was not easy getting your attention with this problem :)
Marc
-- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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