diff options
Diffstat (limited to 'drivers/cpuidle/driver.c')
| -rw-r--r-- | drivers/cpuidle/driver.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index 3f7e3cedd13..284d7af5a9c 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -17,6 +17,30 @@ static struct cpuidle_driver *cpuidle_curr_driver; DEFINE_SPINLOCK(cpuidle_driver_lock); +static void __cpuidle_register_driver(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. + */ + if (!drv->power_specified) { + 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 @@ -34,6 +58,7 @@ int cpuidle_register_driver(struct cpuidle_driver *drv) spin_unlock(&cpuidle_driver_lock); return -EBUSY; } + __cpuidle_register_driver(drv); cpuidle_curr_driver = drv; spin_unlock(&cpuidle_driver_lock); |