Subject: Re: [PATCH] powerpc/85xx: Add back condition for smp

From: Scott Wood <[email-masked]>
Date: Tue, 17 Apr 2012 17:17:50 -0500

On 04/17/2012 04:39 PM, York Sun wrote:
> The timebase synchronization is only necessary if we need to reset a
> separate core.  Currently only KEXEC and CPU hotplug require resetting
> a single core. The following code should be in the condition of
> CONFIG_KEXEC or CONFIG_HOTPLUG_CPU
> 
>         .give_timebase  = smp_generic_give_timebase,
>         .take_timebase  = smp_generic_take_timebase,
> 
> Signed-off-by: York Sun <[email-masked]>
> Acked-by: Li Yang <[email-masked]>
> ---
>  arch/powerpc/platforms/85xx/smp.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
> index 56942af..868c6d7 100644
> --- a/arch/powerpc/platforms/85xx/smp.c
> +++ b/arch/powerpc/platforms/85xx/smp.c
> @@ -192,8 +192,10 @@ struct smp_ops_t smp_85xx_ops = {
>  	.cpu_disable	= generic_cpu_disable,
>  	.cpu_die	= generic_cpu_die,
>  #endif
> +#if defined(CONFIG_KEXEC) || defined(CONFIG_HOTPLUG_CPU)
>  	.give_timebase	= smp_generic_give_timebase,
>  	.take_timebase	= smp_generic_take_timebase,
> +#endif
>  };
>  
>  #ifdef CONFIG_KEXEC

Note that this is only a temporary fix, that assumes the environments
where tbsync is problematic[1] (virtualization and simulation) do not
enable CONFIG_KEXEC or CONFIG_HOTPLUG_CPU.  Eventually the sync should
be done via CCSR like in U-Boot, and the decision on whether to do it
should be runtime.

-Scott

[1] More so than usual.