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Re: [PATCH] ARM: Drop fixed 200 Hz timer requirement from Exynos platforms

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On Monday, November 14, 2016 8:27:05 PM CET Krzysztof Kozlowski wrote:
> @@ -1497,7 +1497,7 @@ source kernel/Kconfig.preempt
>  config HZ_FIXED
>         int
>         default 200 if ARCH_EBSA110 || ARCH_S3C24XX || \
> -               ARCH_S5PV210 || ARCH_EXYNOS4
> +               ARCH_S5PV210
>         default 128 if SOC_AT91RM9200
>         default 0

After further research, I've concluded that we should also drop the
settings for ARCH_S5PV210 and ARCH_S3C24XX here.

ARCH_S5PV210 behaves exactly like EXYNOS here, it has 32-bit timers
so there won't be any overflow with 100Hz.

For ARCH_S3C24XX, it the requirement was that HZ_100 could not
be used with the old arch/arm/plat-samsung/time.c code that would
overflow its 16-bit counter.
However, the new drivers/clocksource/samsung_pwm_timer.c configures
the clock divider to '50' instead of '6', so there is no longer
a 16-bit overflow before the 100Hz tick, it now overflows every
3.7ms for the typical 12MHz clock.

	Arnd

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[PATCH] ARM: Drop fixed 200 Hz timer requirement from Exynos platforms Krzysztof Kozlowski <krzk@kernel.org> - 2016-11-14 19:30 +0100
  Re: [PATCH] ARM: Drop fixed 200 Hz timer requirement from Exynos platforms Arnd Bergmann <arnd@arndb.de> - 2016-11-17 15:40 +0100
    Re: [PATCH] ARM: Drop fixed 200 Hz timer requirement from Exynos  platforms Krzysztof Kozlowski <krzk@kernel.org> - 2016-11-18 07:50 +0100
  Re: [PATCH] ARM: Drop fixed 200 Hz timer requirement from Exynos  platforms Javier Martinez Canillas <javier@osg.samsung.com> - 2016-11-17 18:40 +0100

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