[PATCH] clocksource; armada-370: implement ARM delay timer

Gregory CLEMENT gregory.clement at free-electrons.com
Mon Oct 19 08:19:24 PDT 2015


Hi Russell,
 
 On lun., oct. 19 2015, Russell King <rmk+kernel at arm.linux.org.uk> wrote:

> Implement an ARM delay timer to be used for udelay() on Armada 37x
> platforms.  This allows us to skip the delay loop calibration at boot,
> saving 180ms on the boot time of the kernel (which is around 10%).
>
> It also means that udelay() will be unaffected by CPU frequency changes
> when cpufreq is enabled on these platforms.
>
> Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
> ---
>  arch/arm/Kconfig                         |  1 +
>  arch/arm/plat-orion/time.c               | 13 +++++++++++++

You spoke only about the armada37x but you also modified the timer of
the orion platforms.

Could you split your patch in two part?

Then the arch/arm/plat-orion/time.c related part would be applied
through the mvebu tree and the drivers/clocksource/time-armada-370-xp.c
through the clocksource tree.


>  drivers/clocksource/time-armada-370-xp.c | 14 ++++++++++++++
>  3 files changed, 28 insertions(+)
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index f3dfca632a8a..194569c23271 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -10,6 +10,7 @@ config ARM
>  	select ARCH_SUPPORTS_ATOMIC_RMW
>  	select ARCH_USE_BUILTIN_BSWAP
>  	select ARCH_USE_CMPXCHG_LOCKREF
> +	select ARCH_WANT_FRAME_POINTERS

Is it related to this patch?

Thanks,

Gregory
>  	select ARCH_WANT_IPC_PARSE_VERSION
>  	select BUILDTIME_EXTABLE_SORT if MMU
>  	select CLONE_BACKWARDS

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com



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