Re: [PATCH V2] MIPS: Fix poweroff failure when HOTPLUG_CPU configured.

[Ralf Baechle <ralf@linux-mips.org>]

On Mon, Aug 13, 2012 at 08:52:24PM +0800, Huacai Chen wrote:

> When poweroff machine, kernel_power_off() call disable_nonboot_cpus().
> And if we have HOTPLUG_CPU configured, disable_nonboot_cpus() is not an
> empty function but attempt to actually disable the nonboot cpus. Since
> system state is SYSTEM_POWER_OFF, play_dead() won't be called and thus
> disable_nonboot_cpus() hangs. Therefore, we make this patch to avoid
> poweroff failure.

> diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
> index e9a5fd7..69b17a9 100644
> --- a/arch/mips/kernel/process.c
> +++ b/arch/mips/kernel/process.c
> @@ -72,9 +72,7 @@ void __noreturn cpu_idle(void)
>  			}
>  		}
>  #ifdef CONFIG_HOTPLUG_CPU
> -		if (!cpu_online(cpu) && !cpu_isset(cpu, cpu_callin_map) &&
> -		    (system_state == SYSTEM_RUNNING ||
> -		     system_state == SYSTEM_BOOTING))
> +		if (!cpu_online(cpu) && !cpu_isset(cpu, cpu_callin_map))

Looks good - but I'm wondering if the "!cpu_isset(cpu, cpu_callin_map)"
can be removed as well?

Also, which -stable branches is this patch applicable?

  Ralf