On 06/04/2013 12:48 PM, Joseph Lo wrote:
> This supports CPU core power down on each CPU when CPU idle. When CPU go
> into this state, it saves it's context and needs a proper configuration
> in flow controller to power gate the CPU when CPU runs into WFI
> instruction. And the CPU also needs to set the IRQ as CPU power down idle
> wake up event in flow controller.
>
> Signed-off-by: Joseph Lo <[email protected]>
I would like to understand why there is a WARN with the
CPUIDLE_FLAG_TIMER_STOP flag set before queuing this patch and ensure it
is not the tree hiding the forest.
Thanks
-- Daniel
> ---
> V2:
> * remove some redundant code of memory barrier
> * remove the function declaration by rearranging the coding sequence
> ---
> arch/arm/mach-tegra/cpuidle-tegra114.c | 51
> +++++++++++++++++++++++++++++++++-
> 1 file changed, 50 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c
> b/arch/arm/mach-tegra/cpuidle-tegra114.c
> index 1d1c602..e0b8730 100644
> --- a/arch/arm/mach-tegra/cpuidle-tegra114.c
> +++ b/arch/arm/mach-tegra/cpuidle-tegra114.c
> @@ -17,15 +17,64 @@
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/cpuidle.h>
> +#include <linux/cpu_pm.h>
> +#include <linux/clockchips.h>
>
> #include <asm/cpuidle.h>
> +#include <asm/suspend.h>
> +#include <asm/smp_plat.h>
> +
> +#include "pm.h"
> +#include "sleep.h"
> +
> +#ifdef CONFIG_PM_SLEEP
> +#define TEGRA114_MAX_STATES 2
> +#else
> +#define TEGRA114_MAX_STATES 1
> +#endif
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int tegra114_idle_power_down(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv,
> + int index)
> +{
> + local_fiq_disable();
> +
> + tegra_set_cpu_in_lp2();
> + cpu_pm_enter();
> +
> + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
> +
> + cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
> +
> + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
> +
> + cpu_pm_exit();
> + tegra_clear_cpu_in_lp2();
> +
> + local_fiq_enable();
> +
> + return index;
> +}
> +#endif
>
> static struct cpuidle_driver tegra_idle_driver = {
> .name = "tegra_idle",
> .owner = THIS_MODULE,
> - .state_count = 1,
> + .state_count = TEGRA114_MAX_STATES,
> .states = {
> [0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
> +#ifdef CONFIG_PM_SLEEP
> + [1] = {
> + .enter = tegra114_idle_power_down,
> + .exit_latency = 500,
> + .target_residency = 1000,
> + .power_usage = 0,
> + .flags = CPUIDLE_FLAG_TIME_VALID,
> + .name = "powered-down",
> + .desc = "CPU power gated",
> + },
> +#endif
> },
> };
>
>
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