1 files changed, 38 insertions, 20 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 96a69c67a545..55e9795801a4 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1201,28 +1201,39 @@ static int cpufreq_online(unsigned int cpu)
 			return -ENOMEM;
 	}
 
-	cpumask_copy(policy->cpus, cpumask_of(cpu));
+	if (!new_policy && cpufreq_driver->online) {
+		ret = cpufreq_driver->online(policy);
+		if (ret) {
+			pr_debug("%s: %d: initialization failed\n", __func__,
+				 __LINE__);
+			goto out_exit_policy;
+		}
 
-	/* call driver. From then on the cpufreq must be able
-	 * to accept all calls to ->verify and ->setpolicy for this CPU
-	 */
-	ret = cpufreq_driver->init(policy);
-	if (ret) {
-		pr_debug("initialization failed\n");
-		goto out_free_policy;
-	}
+		/* Recover policy->cpus using related_cpus */
+		cpumask_copy(policy->cpus, policy->related_cpus);
+	} else {
+		cpumask_copy(policy->cpus, cpumask_of(cpu));
 
-	ret = cpufreq_table_validate_and_sort(policy);
-	if (ret)
-		goto out_exit_policy;
+		/*
+		 * Call driver. From then on the cpufreq must be able
+		 * to accept all calls to ->verify and ->setpolicy for this CPU.
+		 */
+		ret = cpufreq_driver->init(policy);
+		if (ret) {
+			pr_debug("%s: %d: initialization failed\n", __func__,
+				 __LINE__);
+			goto out_free_policy;
+		}
 
-	down_write(&policy->rwsem);
+		ret = cpufreq_table_validate_and_sort(policy);
+		if (ret)
+			goto out_exit_policy;
 
-	if (new_policy) {
 		/* related_cpus should at least include policy->cpus. */
 		cpumask_copy(policy->related_cpus, policy->cpus);
 	}
 
+	down_write(&policy->rwsem);
 	/*
 	 * affected cpus must always be the one, which are online. We aren't
 	 * managing offline cpus here.
@@ -1421,11 +1432,12 @@ static int cpufreq_offline(unsigned int cpu)
 		cpufreq_exit_governor(policy);
 
 	/*
-	 * 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.
+	 * Perform the ->offline() during light-weight tear-down, as
+	 * that allows fast recovery when the CPU comes back.
 	 */
-	if (cpufreq_driver->exit) {
+	if (cpufreq_driver->offline) {
+		cpufreq_driver->offline(policy);
+	} else if (cpufreq_driver->exit) {
 		cpufreq_driver->exit(policy);
 		policy->freq_table = NULL;
 	}
@@ -1454,8 +1466,13 @@ static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
 	cpumask_clear_cpu(cpu, policy->real_cpus);
 	remove_cpu_dev_symlink(policy, dev);
 
-	if (cpumask_empty(policy->real_cpus))
+	if (cpumask_empty(policy->real_cpus)) {
+		/* We did light-weight exit earlier, do full tear down now */
+		if (cpufreq_driver->offline)
+			cpufreq_driver->exit(policy);
+
 		cpufreq_policy_free(policy);
+	}
 }
 
 /**
@@ -2488,7 +2505,8 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
 		    driver_data->target) ||
 	     (driver_data->setpolicy && (driver_data->target_index ||
 		    driver_data->target)) ||
-	     (!!driver_data->get_intermediate != !!driver_data->target_intermediate))
+	     (!!driver_data->get_intermediate != !!driver_data->target_intermediate) ||
+	     (!driver_data->online != !driver_data->offline))
 		return -EINVAL;
 
 	pr_debug("trying to register driver %s\n", driver_data->name);