diff options
Diffstat (limited to 'kernel/cpufreq.c')
| -rw-r--r-- | kernel/cpufreq.c | 115 |
1 files changed, 48 insertions, 67 deletions
diff --git a/kernel/cpufreq.c b/kernel/cpufreq.c index 6ae2b821830e..f4864ce54aae 100644 --- a/kernel/cpufreq.c +++ b/kernel/cpufreq.c @@ -23,6 +23,7 @@ #include <linux/device.h> #include <linux/slab.h> #include <linux/cpu.h> +#include <linux/completion.h> /** * The "cpufreq driver" - the arch- or hardware-dependend low @@ -297,6 +298,12 @@ static ssize_t store(struct kobject * kobj, struct attribute * attr, return ret; } +static void cpufreq_sysfs_release(struct kobject * kobj) +{ + struct cpufreq_policy * policy = to_policy(kobj); + complete(&policy->kobj_unregister); +} + static struct sysfs_ops sysfs_ops = { .show = show, .store = store, @@ -305,6 +312,7 @@ static struct sysfs_ops sysfs_ops = { static struct kobj_type ktype_cpufreq = { .sysfs_ops = &sysfs_ops, .default_attrs = default_attrs, + .release = cpufreq_sysfs_release, }; @@ -329,11 +337,9 @@ static int cpufreq_add_dev (struct sys_device * sys_dev) */ policy = &cpufreq_driver->policy[cpu]; policy->cpu = cpu; - if (cpufreq_driver->init) { - ret = cpufreq_driver->init(policy); - if (ret) - goto out; - } + ret = cpufreq_driver->init(policy); + if (ret) + goto out; /* set default policy on this CPU */ down(&cpufreq_driver_sem); @@ -343,6 +349,8 @@ static int cpufreq_add_dev (struct sys_device * sys_dev) up(&cpufreq_driver_sem); init_MUTEX(&policy->lock); + init_completion(&policy->kobj_unregister); + /* prepare interface data */ policy->kobj.parent = &sys_dev->kobj; policy->kobj.ktype = &ktype_cpufreq; @@ -352,18 +360,19 @@ static int cpufreq_add_dev (struct sys_device * sys_dev) if (ret) goto out; + /* set up files for this cpu device */ drv_attr = cpufreq_driver->attr; while ((drv_attr) && (*drv_attr)) { sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); drv_attr++; } - /* set up files for this cpu device */ - /* set default policy */ ret = cpufreq_set_policy(&new_policy); - if (ret) + if (ret) { kobject_unregister(&policy->kobj); + wait_for_completion(&policy->kobj_unregister); + } out: module_put(cpufreq_driver->owner); @@ -401,10 +410,39 @@ static int cpufreq_remove_dev (struct sys_device * sys_dev) up(&cpufreq_driver_sem); kobject_put(&cpufreq_driver->policy[cpu].kobj); + + /* we need to make sure that the underlying kobj is actually + * destroyed before we proceed e.g. with cpufreq driver module + * unloading + */ + wait_for_completion(&cpufreq_driver->policy[cpu].kobj_unregister); + return 0; } -static int cpufreq_restore(struct sys_device *); +/** + * cpufreq_restore - restore the CPU clock frequency after resume + * + * Restore the CPU clock frequency so that our idea of the current + * frequency reflects the actual hardware. + */ +static int cpufreq_restore(struct sys_device * sysdev) +{ + int cpu = sysdev->id; + unsigned int ret = 0; + struct cpufreq_policy policy; + + if (cpu_online(cpu) && cpufreq_cpu_get(cpu)) { + down(&cpufreq_driver_sem); + memcpy(&policy, &cpufreq_driver->policy[cpu], + sizeof(struct cpufreq_policy)); + up(&cpufreq_driver_sem); + ret = cpufreq_set_policy(&policy); + cpufreq_cpu_put(cpu); + } + + return ret; +} static struct sysdev_driver cpufreq_sysdev_driver = { .add = cpufreq_add_dev, @@ -587,33 +625,10 @@ EXPORT_SYMBOL_GPL(cpufreq_register_governor); void cpufreq_unregister_governor(struct cpufreq_governor *governor) { - unsigned int i; - if (!governor) return; down(&cpufreq_governor_sem); - - /* - * Unless the user uses rmmod -f, we can be safe. But we never - * know, so check whether if it's currently used. If so, - * stop it and replace it with the default governor. - */ - for (i=0; i<NR_CPUS; i++) - { - if (!cpufreq_cpu_get(i)) - continue; - if ((cpufreq_driver->policy[i].policy == CPUFREQ_POLICY_GOVERNOR) && - (cpufreq_driver->policy[i].governor == governor)) { - cpufreq_governor(i, CPUFREQ_GOV_STOP); - cpufreq_driver->policy[i].policy = CPUFREQ_POLICY_PERFORMANCE; - cpufreq_governor(i, CPUFREQ_GOV_START); - cpufreq_governor(i, CPUFREQ_GOV_LIMITS); - } - cpufreq_cpu_put(i); - } - - /* now we can safely remove it from the list */ list_del(&governor->governor_list); up(&cpufreq_governor_sem); return; @@ -781,7 +796,7 @@ void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) switch (state) { case CPUFREQ_PRECHANGE: notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_PRECHANGE, freqs); - adjust_jiffies(CPUFREQ_PRECHANGE, freqs); + adjust_jiffies(CPUFREQ_PRECHANGE, freqs); break; case CPUFREQ_POSTCHANGE: adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); @@ -859,37 +874,3 @@ int cpufreq_unregister_driver(struct cpufreq_driver *driver) return 0; } EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); - - -#ifdef CONFIG_PM - -/** - * cpufreq_restore - restore the CPU clock frequency after resume - * - * Restore the CPU clock frequency so that our idea of the current - * frequency reflects the actual hardware. - */ -static int cpufreq_restore(struct sys_device * sysdev) -{ - int cpu = sysdev->id; - unsigned int ret = 0; - struct cpufreq_policy policy; - - if (cpu_online(cpu) && cpufreq_cpu_get(cpu)) { - down(&cpufreq_driver_sem); - memcpy(&policy, &cpufreq_driver->policy[cpu], - sizeof(struct cpufreq_policy)); - up(&cpufreq_driver_sem); - ret = cpufreq_set_policy(&policy); - cpufreq_cpu_put(cpu); - } - - return ret; -} - -#else -static int cpufreq_restore(struct sys_device * sysdev) -{ - return 0; -} -#endif /* CONFIG_PM */ |