diff options
| author | Len Brown <len.brown@intel.com> | 2011-04-01 18:13:10 -0400 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2011-08-03 19:06:36 -0400 |
| commit | 62027aea23fcd14478abdddd3b74a4e0f5fb2984 (patch) | |
| tree | 1aaa5c1872e296f3448ae6c126175ac9d998e3b4 /drivers/cpuidle | |
| parent | 6dccf9c508d5d773859df1cc2dce75c5b19e35a0 (diff) | |
| download | lwn-62027aea23fcd14478abdddd3b74a4e0f5fb2984.tar.gz lwn-62027aea23fcd14478abdddd3b74a4e0f5fb2984.zip | |
cpuidle: create bootparam "cpuidle.off=1"
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.brown@intel.com>
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 10 | ||||
| -rw-r--r-- | drivers/cpuidle/cpuidle.h | 1 | ||||
| -rw-r--r-- | drivers/cpuidle/driver.c | 3 | ||||
| -rw-r--r-- | drivers/cpuidle/governor.c | 3 |
4 files changed, 17 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index bf5092455a8f..faae2c357bab 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) @@ -427,6 +433,9 @@ 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); @@ -438,4 +447,5 @@ 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 33e50d556f17..38c3fd8b9d76 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 fd1601e3d125..3f7e3cedd133 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -26,6 +26,9 @@ 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 724c164d31c9..ea2f8e7aa24a 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; |