Messages in this thread Patch in this message | | | From | Julius Werner <> | Subject | [PATCH] cpuidle: reinitialize power_usage values when adding/removing C-states | Date | Tue, 16 Oct 2012 15:39:44 -0700 |
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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> --- 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); -- 1.7.8.6
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