[PATCH RFC 13/27] ARM: cpuidle: Add runtime PM support for CPU idle

[Kevin Hilman]

Lina Iyer <lina.iyer at linaro.org> writes:

> Notify runtime PM when the CPU is going to be powered off in the idle
> state. This allows for runtime PM suspend/resume of the CPU as well as
> its PM domain.
>
> Cc: Daniel Lezcano <daniel.lezcano at linaro.org>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
> Signed-off-by: Lina Iyer <lina.iyer at linaro.org>
> ---
>  drivers/cpuidle/cpuidle-arm.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
> index 545069d..8e72a23 100644
> --- a/drivers/cpuidle/cpuidle-arm.c
> +++ b/drivers/cpuidle/cpuidle-arm.c
> @@ -11,13 +11,16 @@
>  
>  #define pr_fmt(fmt) "CPUidle arm: " fmt
>  
> +#include <linux/cpu.h>
>  #include <linux/cpuidle.h>
>  #include <linux/cpumask.h>
>  #include <linux/cpu_pm.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/slab.h>
> +#include <linux/rcupdate.h>
>  
>  #include <asm/cpuidle.h>
>  
> @@ -45,6 +48,10 @@ static int arm_enter_idle_state(struct cpuidle_device *dev,
>  
>  	ret = cpu_pm_enter();
>  	if (!ret) {
> +		struct device *cpu_dev = get_cpu_device(dev->cpu);
> +
> +		RCU_NONIDLE(pm_runtime_put_sync_suspend(cpu_dev));
> +

A comment in the changelog about the use of _put_sync_suspend() instead
of a normal _put_sync() would be helpful for this patch.

Kevin