[PATCH v2] ARM: EXYNOS: Use MCPM call-backs to support S2R on Exynos5420

[Nicolas Pitre]

On Mon, 30 Jun 2014, Abhilash Kesavan wrote:

> Use the MCPM layer to handle core suspend/resume on Exynos5420.
> Also, restore the entry address setup code post-resume.
> 
> Signed-off-by: Abhilash Kesavan <a.kesavan at samsung.com>
> ---
[...]

Could you tell me more about this?

> @@ -150,7 +153,13 @@ static void exynos_power_down(void)
>  	BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
>  	cpu_use_count[cpu][cluster]--;
>  	if (cpu_use_count[cpu][cluster] == 0) {
> -		exynos_cpu_power_down(cpunr);
> +		/*
> +		 * Bypass power down for CPU0 during suspend. This is being
> +		 * taken care by the SYS_PWR_CFG bit in CORE0_SYS_PWR_REG.
> +		 */
> +		if ((cpunr != 0) ||
> +		(__raw_readl(pmu_base_addr + S5P_INFORM1) != S5P_CHECK_SLEEP))
> +			exynos_cpu_power_down(cpunr);

What happens if CPU0 is the first in the cluster to be idled?  Will it 
remain powered up until all the others have gone idle too?


Nicolas