diff options
Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 27 |
1 files changed, 11 insertions, 16 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 6c6121b85a5..23a63207d74 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -38,7 +38,6 @@ static struct cpufreq_driver *cpufreq_driver; static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS]; static DEFINE_SPINLOCK(cpufreq_driver_lock); - /* internal prototypes */ static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); static void handle_update(void *data); @@ -593,12 +592,11 @@ static int cpufreq_add_dev (struct sys_device * sys_dev) goto module_out; } - policy = kmalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); + policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); if (!policy) { ret = -ENOMEM; goto nomem_out; } - memset(policy, 0, sizeof(struct cpufreq_policy)); policy->cpu = cpu; policy->cpus = cpumask_of_cpu(cpu); @@ -1116,24 +1114,21 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy, int retval = -EINVAL; /* - * Converted the lock_cpu_hotplug to preempt_disable() - * and preempt_enable(). This is a bit kludgy and relies on how cpu - * hotplug works. All we need is a guarantee that cpu hotplug won't make - * progress on any cpu. Once we do preempt_disable(), this would ensure - * that hotplug threads don't get onto this cpu, thereby delaying - * the cpu remove process. - * - * We removed the lock_cpu_hotplug since we need to call this function - * via cpu hotplug callbacks, which result in locking the cpu hotplug - * thread itself. Agree this is not very clean, cpufreq community - * could improve this if required. - Ashok Raj <ashok.raj@intel.com> + * If we are already in context of hotplug thread, we dont need to + * acquire the hotplug lock. Otherwise acquire cpucontrol to prevent + * hotplug from removing this cpu that we are working on. */ - preempt_disable(); + if (!current_in_cpu_hotplug()) + lock_cpu_hotplug(); + dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, target_freq, relation); if (cpu_online(policy->cpu) && cpufreq_driver->target) retval = cpufreq_driver->target(policy, target_freq, relation); - preempt_enable(); + + if (!current_in_cpu_hotplug()) + unlock_cpu_hotplug(); + return retval; } EXPORT_SYMBOL_GPL(__cpufreq_driver_target); |