Subject: [PATCH] ARM: EXYNOS: Use wfi macro in platform_do_lowpower

From: [email-masked] (Daniel Lezcano)
Date: Thu, 22 May 2014 13:53:20 +0200

On 05/22/2014 09:57 AM, Leela Krishna Amudala wrote:
> This patch is originally based on commit b3377d186572 ("ARM: 7064/1:
> vexpress: Use wfi macro in platform_do_lowpower.")
>
> Current Exynos CPU hotplug code includes a hardcoded WFI
> instruction, in ARM encoding.  When the kernel is compiled in Thumb-2
> mode, this is invalid and causes the machine to hang hard when a CPU
> is offlined.
>
> Use wfi macro instead of the hardcoded WFI instruction.

Is it possible to change it for cpu_do_idle() ?

I guess, that should be backported to the previous kernel version, right 
? (Cc stable@).

Thanks
   -- Daniel

> Signed-off-by: Leela Krishna Amudala <[email-masked]>
> ---
>   arch/arm/mach-exynos/hotplug.c |    8 +-------
>   1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/arch/arm/mach-exynos/hotplug.c b/arch/arm/mach-exynos/hotplug.c
> index 69fa483..8a134d0 100644
> --- a/arch/arm/mach-exynos/hotplug.c
> +++ b/arch/arm/mach-exynos/hotplug.c
> @@ -46,13 +46,7 @@ static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
>   		if (cpu == 1)
>   			exynos_cpu_power_down(cpu);
>
> -		/*
> -		 * here's the WFI
> -		 */
> -		asm(".word	0xe320f003\n"
> -		    :
> -		    :
> -		    : "memory", "cc");
> +		wfi();
>
>   		if (pen_release == cpu_logical_map(cpu)) {
>   			/*
>

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