Re: [PATCH 2/2] ARM: vf610: Use ARM Global Timer as clocksource

Shawn Guo
2014-09-25T07:51:24Z

On Thu, Sep 11, 2014 at 02:06:15PM +0200, Stefan Agner wrote:
> Use ARM Global Timer as clocksource instead of the PIT timer. This
> leaves the PIT timer for other users e.g. the secondary Cortex-M4
> core. Also, the Global Timer has double the precission (running at
> pheripheral clock compared to IPG clock) and a 64-bit incrementing
> counter register.

I just think of one thing. Will this change cause a problem of the low
power idle support in case we want to power down ARM core in there?

Shawn

>
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
> Theoretically we could remove the PIT driver now. But we could also
> enable both drivers, but is having two clock source useful for the
> Kernel at all?
>
> arch/arm/mach-imx/Kconfig | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
> index 64161aa..adc77180 100644
> --- a/arch/arm/mach-imx/Kconfig
> +++ b/arch/arm/mach-imx/Kconfig
> @@ -656,7 +656,8 @@ config SOC_VF610
> bool "Vybrid Family VF610 support"
> select ARM_GIC
> select PINCTRL_VF610
> - select VF_PIT_TIMER
> + select ARM_GLOBAL_TIMER
> + select CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
> select PL310_ERRATA_769419 if CACHE_L2X0
>
> help
> --
> 2.1.0
>