[RFC][PATCH 2/7] ARM: OMAP4: cpuidle - Declare the states with the driver declaration

Jean Pihet jean.pihet at newoldbits.com
Wed Mar 21 13:31:46 UTC 2012


On Wed, Mar 21, 2012 at 10:27 AM, Daniel Lezcano
<daniel.lezcano at linaro.org> wrote:
> The cpuidle API allows to declare statically the states in the driver
> structure. Let's use it.
> We do no longer need the fill_cstate function called at runtime and
> by the way adding more instructions at boot time.
>
> Signed-off-by: Daniel Lezcano <daniel.lezcano at linaro.org>
> ---
>  arch/arm/mach-omap2/cpuidle44xx.c |   56 +++++++++++++++++++++----------------
>  1 files changed, 32 insertions(+), 24 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c
> index 1210229..cd6bee7 100644
> --- a/arch/arm/mach-omap2/cpuidle44xx.c
> +++ b/arch/arm/mach-omap2/cpuidle44xx.c
> @@ -148,21 +148,38 @@ DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);
>  struct cpuidle_driver omap4_idle_driver = {
>        .name =         "omap4_idle",
>        .owner =        THIS_MODULE,
> +       .states = {
> +               {
> +                       /* C1 - CPU0 ON + CPU1 ON + MPU ON */
> +                       .exit_latency = 2 + 2,
> +                       .target_residency = 5,
> +                       .flags = CPUIDLE_FLAG_TIME_VALID,
> +                       .enter = omap4_enter_idle,
> +                       .name = "C1",
> +                       .desc = "MPUSS ON"
> +               },
...
> +       },
> +       .state_count = OMAP4_NUM_STATES,
>  };
>
> -static inline void _fill_cstate(struct cpuidle_driver *drv,
> -                                       int idx, const char *descr)
> -{
> -       struct cpuidle_state *state = &drv->states[idx];
> -
> -       state->exit_latency     = cpuidle_params_table[idx].exit_latency;
> -       state->target_residency = cpuidle_params_table[idx].target_residency;
> -       state->flags            = CPUIDLE_FLAG_TIME_VALID;
> -       state->enter            = omap4_enter_idle;
> -       sprintf(state->name, "C%d", idx + 1);
> -       strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
> -}
I am OK with this change, which makes the code more readable (and so
maintainable).

> -
>  static inline struct omap4_idle_statedata *_fill_cstate_usage(
>                                        struct cpuidle_device *dev,
>                                        int idx)
> @@ -196,37 +213,28 @@ int __init omap4_idle_init(void)
>        if ((!mpu_pd) || (!cpu0_pd) || (!cpu1_pd))
>                return -ENODEV;
>
> -
> -       drv->safe_state_index = -1;
>        dev = &per_cpu(omap4_idle_dev, cpu_id);
>        dev->cpu = cpu_id;
>
> -       /* C1 - CPU0 ON + CPU1 ON + MPU ON */
> -       _fill_cstate(drv, 0, "MPUSS ON");
> -       drv->safe_state_index = 0;
I would keep this or add a clear comment that C1 is the safe state.

...

Thanks,
Jean

> --
> 1.7.5.4
>
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