diff options
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 69 |
1 files changed, 53 insertions, 16 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 1d041aff4d48..e0ace3d9382c 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -44,6 +44,7 @@ */ static struct cpufreq_driver *cpufreq_driver; static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); +static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback); static DEFINE_RWLOCK(cpufreq_driver_lock); static DEFINE_MUTEX(cpufreq_governor_lock); @@ -946,6 +947,20 @@ static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, } #endif +static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) +{ + struct cpufreq_policy *policy; + unsigned long flags; + + write_lock_irqsave(&cpufreq_driver_lock, flags); + + policy = per_cpu(cpufreq_cpu_data_fallback, cpu); + + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + return policy; +} + static struct cpufreq_policy *cpufreq_policy_alloc(void) { struct cpufreq_policy *policy; @@ -1023,7 +1038,12 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, goto module_out; } - policy = cpufreq_policy_alloc(); + if (frozen) + /* Restore the saved policy when doing light-weight init */ + policy = cpufreq_policy_restore(cpu); + else + policy = cpufreq_policy_alloc(); + if (!policy) goto nomem_out; @@ -1204,6 +1224,10 @@ static int __cpufreq_remove_dev(struct device *dev, data = per_cpu(cpufreq_cpu_data, cpu); per_cpu(cpufreq_cpu_data, cpu) = NULL; + /* Save the policy somewhere when doing a light-weight tear-down */ + if (frozen) + per_cpu(cpufreq_cpu_data_fallback, cpu) = data; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); if (!data) { @@ -1249,27 +1273,40 @@ static int __cpufreq_remove_dev(struct device *dev, if (cpufreq_driver->target) __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); - lock_policy_rwsem_read(cpu); - kobj = &data->kobj; - cmp = &data->kobj_unregister; - unlock_policy_rwsem_read(cpu); - kobject_put(kobj); + if (!frozen) { + lock_policy_rwsem_read(cpu); + kobj = &data->kobj; + cmp = &data->kobj_unregister; + unlock_policy_rwsem_read(cpu); + kobject_put(kobj); + + /* + * We need to make sure that the underlying kobj is + * actually not referenced anymore by anybody before we + * proceed with unloading. + */ + pr_debug("waiting for dropping of refcount\n"); + wait_for_completion(cmp); + pr_debug("wait complete\n"); + } - /* we need to make sure that the underlying kobj is actually - * not referenced anymore by anybody before we proceed with - * unloading. + /* + * Perform the ->exit() even during light-weight tear-down, + * since this is a core component, and is essential for the + * subsequent light-weight ->init() to succeed. */ - pr_debug("waiting for dropping of refcount\n"); - wait_for_completion(cmp); - pr_debug("wait complete\n"); - if (cpufreq_driver->exit) cpufreq_driver->exit(data); - cpufreq_policy_free(data); + if (!frozen) + cpufreq_policy_free(data); } else { - pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); - cpufreq_cpu_put(data); + + if (!frozen) { + pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); + cpufreq_cpu_put(data); + } + if (cpufreq_driver->target) { __cpufreq_governor(data, CPUFREQ_GOV_START); __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |