On Tue, May 19, 2015 at 03:49:12PM +0100, Tomeu Vizoso wrote:
> This callback is expected to do the same as enter() but it has to
> guarantee that interrupts aren't enabled at any point in its execution,
> as the tick is frozen.
>
> It will be called when the system goes to suspend-to-idle and will
> reduce power usage because CPUs won't be awaken for unnecessary IRQs.
>
> By setting the CPUIDLE_FLAG_TIMER_STOP flag, we can reuse the same code
> for both the enter() and enter_freeze() callbacks.
>
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
> Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> ---
>
> v3: * Set CPUIDLE_FLAG_TIMER_STOP to simplify things as suggested by
> Lorenzo Pieralisi
> v2: * Disable FIQs also when suspending-to-idle
> ---
> arch/arm/mach-tegra/cpuidle-tegra114.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c
> index 155807f..7e59ac0 100644
> --- a/arch/arm/mach-tegra/cpuidle-tegra114.c
> +++ b/arch/arm/mach-tegra/cpuidle-tegra114.c
> @@ -44,16 +44,12 @@ static int tegra114_idle_power_down(struct cpuidle_device *dev,
> tegra_set_cpu_in_lp2();
> cpu_pm_enter();
>
> - tick_broadcast_enter();
> -
> call_firmware_op(prepare_idle);
>
> /* Do suspend by ourselves if the firmware does not implement it */
> if (call_firmware_op(do_idle, 0) == -ENOSYS)
> cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
>
> - tick_broadcast_exit();
> -
> cpu_pm_exit();
> tegra_clear_cpu_in_lp2();
>
> @@ -61,6 +57,13 @@ static int tegra114_idle_power_down(struct cpuidle_device *dev,
>
> return index;
> }
> +
> +static void tegra114_idle_enter_freeze(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv,
> + int index)
> +{
> + tegra114_idle_power_down(dev, drv, index);
> +}
You do not need this function, remove it and update the enter_freeze
pointer below with tegra114_idle_power_down please.
Thanks,
Lorenzo
> #endif
>
> static struct cpuidle_driver tegra_idle_driver = {
> @@ -72,8 +75,10 @@ static struct cpuidle_driver tegra_idle_driver = {
> #ifdef CONFIG_PM_SLEEP
> [1] = {
> .enter = tegra114_idle_power_down,
> + .enter_freeze = tegra114_idle_enter_freeze,
> .exit_latency = 500,
> .target_residency = 1000,
> + .flags = CPUIDLE_FLAG_TIMER_STOP,
> .power_usage = 0,
> .name = "powered-down",
> .desc = "CPU power gated",
> --
> 2.4.1
>
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