On Tue, 2011-06-07 at 21:59 +0530, Trinabh Gupta wrote:
> From: Len Brown <len.br...@intel.com>
> 
> useful for disabling cpuidle to fall back
> to architecture-default idle loop
> 
> cpuidle drivers and governors will fail to register.
> on x86 they'll say so:
> 
> intel_idle: intel_idle yielding to (null)
> ACPI: acpi_idle yielding to (null)
> 
> Signed-off-by: Len Brown <len.br...@intel.com>
> ---

When you carry over somebody's patch like this you need to also add your
own signed-off-by.

Have those generic changes been reviewed by whoever is in charge of that
cpuidle framework ?

Cheers,
Ben.

>  Documentation/kernel-parameters.txt |    3 +++
>  drivers/cpuidle/cpuidle.c           |   10 ++++++++++
>  drivers/cpuidle/cpuidle.h           |    1 +
>  drivers/cpuidle/driver.c            |    3 +++
>  drivers/cpuidle/governor.c          |    3 +++
>  5 files changed, 20 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/kernel-parameters.txt 
> b/Documentation/kernel-parameters.txt
> index d9a203b..5697faf 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -546,6 +546,9 @@ bytes respectively. Such letter suffixes can also be 
> entirely omitted.
>                       /proc/<pid>/coredump_filter.
>                       See also Documentation/filesystems/proc.txt.
>  
> +     cpuidle.off=1   [CPU_IDLE]
> +                     disable the cpuidle sub-system
> +
>       cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
>                       Format:
>                       <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
> index 406be83..a171b9e 100644
> --- a/drivers/cpuidle/cpuidle.c
> +++ b/drivers/cpuidle/cpuidle.c
> @@ -28,6 +28,12 @@ LIST_HEAD(cpuidle_detected_devices);
>  static void (*pm_idle_old)(void);
>  
>  static int enabled_devices;
> +static int off __read_mostly;
> +
> +int cpuidle_disabled(void)
> +{
> +     return off;
> +}
>  
>  #if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
>  static void cpuidle_kick_cpus(void)
> @@ -397,6 +403,9 @@ static int __init cpuidle_init(void)
>  {
>       int ret;
>  
> +     if (cpuidle_disabled())
> +             return -ENODEV;
> +
>       pm_idle_old = pm_idle;
>  
>       ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
> @@ -408,4 +417,5 @@ static int __init cpuidle_init(void)
>       return 0;
>  }
>  
> +module_param(off, int, 0444);
>  core_initcall(cpuidle_init);
> diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h
> index 33e50d5..38c3fd8 100644
> --- a/drivers/cpuidle/cpuidle.h
> +++ b/drivers/cpuidle/cpuidle.h
> @@ -13,6 +13,7 @@ extern struct list_head cpuidle_governors;
>  extern struct list_head cpuidle_detected_devices;
>  extern struct mutex cpuidle_lock;
>  extern spinlock_t cpuidle_driver_lock;
> +extern int cpuidle_disabled(void);
>  
>  /* idle loop */
>  extern void cpuidle_install_idle_handler(void);
> diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
> index 33e3189..284d7af 100644
> --- a/drivers/cpuidle/driver.c
> +++ b/drivers/cpuidle/driver.c
> @@ -50,6 +50,9 @@ int cpuidle_register_driver(struct cpuidle_driver *drv)
>       if (!drv)
>               return -EINVAL;
>  
> +     if (cpuidle_disabled())
> +             return -ENODEV;
> +
>       spin_lock(&cpuidle_driver_lock);
>       if (cpuidle_curr_driver) {
>               spin_unlock(&cpuidle_driver_lock);
> diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c
> index 724c164..ea2f8e7 100644
> --- a/drivers/cpuidle/governor.c
> +++ b/drivers/cpuidle/governor.c
> @@ -81,6 +81,9 @@ int cpuidle_register_governor(struct cpuidle_governor *gov)
>       if (!gov || !gov->select)
>               return -EINVAL;
>  
> +     if (cpuidle_disabled())
> +             return -ENODEV;
> +
>       mutex_lock(&cpuidle_lock);
>       if (__cpuidle_find_governor(gov->name) == NULL) {
>               ret = 0;
> 
> _______________________________________________
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> Linuxppc-dev@lists.ozlabs.org
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