[PATCH v8 01/11] ARM: brcmstb: add infrastructure for ARM-based Broadcom STB SoCs

[Russell King - ARM Linux]

On Mon, Jul 21, 2014 at 02:07:56PM -0700, Brian Norris wrote:
> +static DEFINE_SPINLOCK(boot_lock);
> +
> +static void brcmstb_secondary_init(unsigned int cpu)
> +{
> +	/*
> +	 * Synchronise with the boot thread.
> +	 */
> +	spin_lock(&boot_lock);
> +	spin_unlock(&boot_lock);
> +}
> +
> +static int brcmstb_boot_secondary(unsigned int cpu, struct task_struct *idle)
> +{
> +	/*
> +	 * set synchronisation state between this boot processor
> +	 * and the secondary one
> +	 */
> +	spin_lock(&boot_lock);
> +
> +	/* Bring up power to the core if necessary */
> +	if (brcmstb_cpu_get_power_state(cpu) == 0)
> +		brcmstb_cpu_power_on(cpu);
> +
> +	brcmstb_cpu_boot(cpu);
> +
> +	/*
> +	 * now the secondary core is starting up let it run its
> +	 * calibrations, then wait for it to finish
> +	 */
> +	spin_unlock(&boot_lock);

I've just read through this code (because it caused my allmodconfig to
break) and spotted this.

What function does boot_lock perform here?  Please, don't quote the
comments (I know where the comments came from) but what I want to hear
is your comments about why you decided to retain this.

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