Messages in this thread | | | Subject | Re: [PATCH 2/2] arm64: dts: mt8173: add timer node | From | Sudeep Holla <> | Date | Thu, 1 Oct 2015 16:32:55 +0100 |
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On 01/10/15 15:33, Yingjoe Chen wrote: > On Thu, 2015-09-17 at 17:13 +0100, Sudeep Holla wrote: >>
[...]
>> >> I think your are confusing the system counter with arch timers. System >> counter is always-on, but the arch timers(logic implementing timers >> comparators) might not be off when the processor is powered down. >> >> I think you need this timer and are using it for low power idle states >> in which case you will use this as a clock event and not clock source. >> It will be used as a hardware broadcast event source. >> >> There's no call to sched_clock_register in mtk_timer.c, so it can't be >> the sched clock, so you need to fix the commit log. > > Hi Sudeep, > > Sorry for late reply. > > For sched_clock_register, please see > http://lists.infradead.org/pipermail/linux-mediatek/2015-July/001547.html > which was accepted in > https://git.linaro.org/people/daniel.lezcano/linux.git/shortlog/refs/heads/clockevents/4.4 >
The commit message makes no sense to me. The counters should continue to work as long as they are in always-on domain. Only timers are lost when you enter deeper idle states. So I agree with using MTK timer as broadcast timer/eventsource. You still didn't answer what's the need to use MTK timer as sched clocksource ?
Regards, Sudeep
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