Re: [PATCH 1/9] ARM: EXYNOS: cpuidle: fix AFTR mode check

[Daniel Lezcano <daniel.lezcano@linaro.org>]

On 08/20/2013 04:23 PM, Bartlomiej Zolnierkiewicz wrote:
> The EXYNOS cpuidle driver code assumes that cpuidle core will handle
> dev->state_count smaller than drv->state_count but currently this is
> untrue (dev->state_count is used only for handling cpuidle state sysfs
> entries and drv->state_count is used for all other cases) and will not
> be fixed in the future as dev->state_count is planned to be removed.
>
> Fix the issue by checking for the max supported idle state in AFTR
> state's ->enter handler (exynos4_enter_lowpower()) and entering AFTR
> mode only when cores other than CPU0 are offline.
>
> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: Kukjin Kim <kgene.kim@samsung.com>

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>

> ---
>   arch/arm/mach-exynos/cpuidle.c | 8 ++------
>   1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c
> index 225ee84..bb8c4e0 100644
> --- a/arch/arm/mach-exynos/cpuidle.c
> +++ b/arch/arm/mach-exynos/cpuidle.c
> @@ -150,8 +150,8 @@ static int exynos4_enter_lowpower(struct cpuidle_device *dev,
>   {
>   	int new_index = index;
>
> -	/* This mode only can be entered when other core's are offline */
> -	if (num_online_cpus() > 1)
> +	/* AFTR can only be entered when cores other than CPU0 are offline */
> +	if (num_online_cpus() > 1 || dev->cpu != 0)
>   		new_index = drv->safe_state_index;
>
>   	if (new_index == 0)
> @@ -210,10 +210,6 @@ static int __init exynos4_init_cpuidle(void)
>   		device = &per_cpu(exynos4_cpuidle_device, cpu_id);
>   		device->cpu = cpu_id;
>
> -		/* Support IDLE only */
> -		if (cpu_id != 0)
> -			device->state_count = 1;
> -
>   		ret = cpuidle_register_device(device);
>   		if (ret) {
>   			printk(KERN_ERR "CPUidle register device failed\n");
>


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