Subject: [PATCH v2] ARM: Don't use complete() during __cpu_die

From: [email-masked] (Stephen Boyd)
Date: Tue, 10 Feb 2015 14:05:01 -0800

On 02/10/15 13:49, Stephen Boyd wrote:
>>> diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
>>> index fe0386c751b2..4d213b24db60 100644
>>> --- a/arch/arm/kernel/smp.c
>>> +++ b/arch/arm/kernel/smp.c
>>> @@ -174,18 +174,19 @@ static int platform_cpu_kill(unsigned int cpu)
>>>  	return 1;
>>>  }
>>>  
>>> -static int platform_cpu_disable(unsigned int cpu)
>>> +int platform_can_hotplug_cpu(unsigned int cpu)
>>>  {
>>>  	if (smp_ops.cpu_disable)
>>> -		return smp_ops.cpu_disable(cpu);
>>> +		return smp_ops.cpu_disable(cpu) ? 0 : 1;
>>>  

BTW, we also need this

        /* cpu_die must be specified to support hotplug */
        if (!smp_ops.cpu_die)
                return 0;

otherwise it seems that we can have a situation where cpu_die() does
nothing besides unexpectedly jump to secondary_start_kernel() before
generic cpu hotplug facilities expect it to.

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