On 10/17/2012 12:39 AM, Julius Werner wrote:
When cpuidle drivers do not supply explicit power_usage values, cpuidle/driver.c inserts dummy values instead. When a running processor dynamically gains new C-states (e.g. after ACPI events), the power_usage values of those states will stay uninitialized, and cpuidle governors will never choose to enter them.
This patch moves the dummy value initialization from cpuidle_register_driver to cpuidle_enable_device, which drivers such as acpi/processor_idle.c will call again when they add or remove C-states. Tested and verified on an Acer AC700 Chromebook, which supports the C3 state only when it switches from AC to battery power.
Signed-off-by: Julius Werner jwerner@chromium.org
This is specific to the acpi and should be handled in the processor_idle.c file instead of the cpuidle core code.
Could be the function 'acpi_processor_cst_has_changed' the right place to set a dummy power value for the power in the new C-state ?
drivers/cpuidle/cpuidle.c | 24 ++++++++++++++++++++++++ drivers/cpuidle/driver.c | 25 ------------------------- 2 files changed, 24 insertions(+), 25 deletions(-)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 7f15b85..bef3a31 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -298,6 +298,28 @@ static void poll_idle_init(struct cpuidle_driver *drv) static void poll_idle_init(struct cpuidle_driver *drv) {} #endif /* CONFIG_ARCH_HAS_CPU_RELAX */ +static void set_power_states(struct cpuidle_driver *drv) +{
- int i;
- /*
* cpuidle driver should set the drv->power_specified bit* before registering if the driver provides* power_usage numbers.** If power_specified is not set,* we fill in power_usage with decreasing values as the* cpuidle code has an implicit assumption that state Cn* uses less power than C(n-1).** With CONFIG_ARCH_HAS_CPU_RELAX, C0 is already assigned* an power value of -1. So we use -2, -3, etc, for other* c-states.*/- for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++)
drv->states[i].power_usage = -1 - i;+}
/**
- cpuidle_enable_device - enables idle PM for a CPU
- @dev: the CPU
@@ -330,6 +352,8 @@ int cpuidle_enable_device(struct cpuidle_device *dev) cpuidle_enter_tk : cpuidle_enter; poll_idle_init(drv);
- if (!drv->power_specified)
set_power_states(drv);if ((ret = cpuidle_add_state_sysfs(dev))) return ret; diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index 87db387..caaed27 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -18,28 +18,6 @@ static struct cpuidle_driver *cpuidle_curr_driver; DEFINE_SPINLOCK(cpuidle_driver_lock); int cpuidle_driver_refcount; -static void set_power_states(struct cpuidle_driver *drv) -{
- int i;
- /*
* cpuidle driver should set the drv->power_specified bit* before registering if the driver provides* power_usage numbers.** If power_specified is not set,* we fill in power_usage with decreasing values as the* cpuidle code has an implicit assumption that state Cn* uses less power than C(n-1).** With CONFIG_ARCH_HAS_CPU_RELAX, C0 is already assigned* an power value of -1. So we use -2, -3, etc, for other* c-states.*/- for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++)
drv->states[i].power_usage = -1 - i;-}
/**
- cpuidle_register_driver - registers a driver
- @drv: the driver
@@ -58,9 +36,6 @@ int cpuidle_register_driver(struct cpuidle_driver *drv) return -EBUSY; }
- if (!drv->power_specified)
set_power_states(drv);- cpuidle_curr_driver = drv;
spin_unlock(&cpuidle_driver_lock);