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

On 03/21/2012 02:31 PM, Jean Pihet wrote:

On Wed, Mar 21, 2012 at 10:27 AM, Daniel Lezcano daniel.lezcano@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 Lezcanodaniel.lezcano@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.

Actually with the driver's states declaration, the safe_state_index is initialized to zero, which means the default safe_state is always 0 with the new API. But I can add the initialization anyway in the structure declaration if you want.

...

Thanks, Jean

...

-- 1.7.5.4

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