Messages in this thread | | | Date | Thu, 15 Jan 2015 12:52:09 +0100 | From | Alexandre Belloni <> | Subject | Re: [PATCH] clocksource: timer-atmel-pit: don't suspend/resume if unused |
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Hi,
I'll do it but only if you review my other series :)
On 15/01/2015 at 12:41:27 +0100, Daniel Lezcano wrote : > On 01/13/2015 11:47 AM, Thomas Gleixner wrote: > >On Mon, 12 Jan 2015, Daniel Lezcano wrote: > > > >>On 01/12/2015 03:04 PM, Nicolas Ferre wrote: > >>>Le 18/12/2014 15:05, Nicolas Ferre a écrit : > >>>>From: Sylvain Rochet <sylvain.rochet@finsecur.com> > >>>> > >>>>Waiting for PIT to stop counting takes a long time: > >>>> 1/(Master clock/prescaler/PIVR) > >>>>= 1/(133 MHz /16 /2^20) > >>>>= 126 ms > >>>> > >>>>Up to 126 ms if master clock is set to 133 MHz, skipping suspend/resume > >>>>of the unused PIT device reduce (suspend time + resume time) from ~140 ms > >>>>to ~17 ms. > >>>> > >>>>Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com> > >>>>[nicolas.ferre@atmel.com: move to newer clocksource driver] > >>>>Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> > >>>>Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > >>>>--- > >>>>Hi Sylvain, > >>>> > >>>>I re-worked (and "Acked") your patch so it can be applied on the newer > >>>>Mainline > >>>>kernels. Beware, I changed the "subject line" as well. The PIT driver > >>>>moved > >>>>recently (3.18). > >>>> > >>>>Daniel, > >>>>Can you take this patch in your tree? > >>> > >>>Hi Daniel, > >>> > >>>Anything prevents this patch from being merged (aka ping ;-))? > >> > >>[Cc'ed tglx]. > >> > >>Hi Nico, > >> > >>thanks for the head up. > >> > >>Nothing prevents it but I am wondering if this change shouldn't be in the > >>generic framework (kernel/time/clocksource.c and kernel/time/clockevents.c), > >>so all drivers will benefit this change ? > > > >Indeed. There is no point in calling suspend/resume for unused > >clockevents. They should be stopped and disabled already. > > Hi Nico, > > are you planning to do the change in the generic framework ? > > Thanks > -- Daniel > > >Now with clocksources this might be different. We have no explicit > >state for this, but its trivial to add one at least for those > >clocksources which have enable/disable callbacks. For the other ones > >not so much. > > > > > > -- > <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs > > Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | > <http://twitter.com/#!/linaroorg> Twitter | > <http://www.linaro.org/linaro-blog/> Blog >
-- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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