Merge git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq

* git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] Make acpi-cpufreq more robust against BIOS freq changes behind our back.
  [CPUFREQ] change cpu freq tables to per_cpu variables
  [CPUFREQ] fix show_trans_table
  [CPUFREQ] Warn when cpufreq_register_notifier called before pure initcalls
  [CPUFREQ] Refactor locking in cpufreq_add_dev
  [CPUFREQ] more CodingStyle
  [CPUFREQ] CodingStyle
  [CPUFREQ] Slightly shorten the error paths of cpufreq_suspend/cpufreq_resume

4 files changed, 88 insertions, 87 deletions

diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index e2d870de837c..8db8f73503b3 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -339,6 +339,7 @@ static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 {
 	struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
 	unsigned int freq;
+	unsigned int cached_freq;
 
 	dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
 
@@ -347,7 +348,16 @@ static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 		return 0;
 	}
 
+	cached_freq = data->freq_table[data->acpi_data->state].frequency;
 	freq = extract_freq(get_cur_val(&cpumask_of_cpu(cpu)), data);
+	if (freq != cached_freq) {
+		/*
+		 * The dreaded BIOS frequency change behind our back.
+		 * Force set the frequency on next target call.
+		 */
+		data->resume = 1;
+	}
+
 	dprintk("cur freq = %u\n", freq);
 
 	return freq;
diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index 9cb43f52f7b6..649ae99b9216 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -97,7 +97,7 @@ static int acpi_processor_apply_limit(struct acpi_processor *pr)
 #define CPUFREQ_THERMAL_MIN_STEP 0
 #define CPUFREQ_THERMAL_MAX_STEP 3
 
-static unsigned int cpufreq_thermal_reduction_pctg[NR_CPUS];
+static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
 static unsigned int acpi_thermal_cpufreq_is_init = 0;
 
 static int cpu_has_cpufreq(unsigned int cpu)
@@ -113,9 +113,9 @@ static int acpi_thermal_cpufreq_increase(unsigned int cpu)
 	if (!cpu_has_cpufreq(cpu))
 		return -ENODEV;
 
-	if (cpufreq_thermal_reduction_pctg[cpu] <
+	if (per_cpu(cpufreq_thermal_reduction_pctg, cpu) <
 		CPUFREQ_THERMAL_MAX_STEP) {
-		cpufreq_thermal_reduction_pctg[cpu]++;
+		per_cpu(cpufreq_thermal_reduction_pctg, cpu)++;
 		cpufreq_update_policy(cpu);
 		return 0;
 	}
@@ -128,14 +128,14 @@ static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
 	if (!cpu_has_cpufreq(cpu))
 		return -ENODEV;
 
-	if (cpufreq_thermal_reduction_pctg[cpu] >
+	if (per_cpu(cpufreq_thermal_reduction_pctg, cpu) >
 		(CPUFREQ_THERMAL_MIN_STEP + 1))
-		cpufreq_thermal_reduction_pctg[cpu]--;
+		per_cpu(cpufreq_thermal_reduction_pctg, cpu)--;
 	else
-		cpufreq_thermal_reduction_pctg[cpu] = 0;
+		per_cpu(cpufreq_thermal_reduction_pctg, cpu) = 0;
 	cpufreq_update_policy(cpu);
 	/* We reached max freq again and can leave passive mode */
-	return !cpufreq_thermal_reduction_pctg[cpu];
+	return !per_cpu(cpufreq_thermal_reduction_pctg, cpu);
 }
 
 static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
@@ -147,9 +147,10 @@ static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
 	if (event != CPUFREQ_ADJUST)
 		goto out;
 
-	max_freq =
-	    (policy->cpuinfo.max_freq *
-	     (100 - cpufreq_thermal_reduction_pctg[policy->cpu] * 20)) / 100;
+	max_freq = (
+	    policy->cpuinfo.max_freq *
+	    (100 - per_cpu(cpufreq_thermal_reduction_pctg, policy->cpu) * 20)
+	) / 100;
 
 	cpufreq_verify_within_limits(policy, 0, max_freq);
 
@@ -174,7 +175,7 @@ static int cpufreq_get_cur_state(unsigned int cpu)
 	if (!cpu_has_cpufreq(cpu))
 		return 0;
 
-	return cpufreq_thermal_reduction_pctg[cpu];
+	return per_cpu(cpufreq_thermal_reduction_pctg, cpu);
 }
 
 static int cpufreq_set_cur_state(unsigned int cpu, int state)
@@ -182,7 +183,7 @@ static int cpufreq_set_cur_state(unsigned int cpu, int state)
 	if (!cpu_has_cpufreq(cpu))
 		return 0;
 
-	cpufreq_thermal_reduction_pctg[cpu] = state;
+	per_cpu(cpufreq_thermal_reduction_pctg, cpu) = state;
 	cpufreq_update_policy(cpu);
 	return 0;
 }
@@ -191,8 +192,9 @@ void acpi_thermal_cpufreq_init(void)
 {
 	int i;
 
-	for (i = 0; i < NR_CPUS; i++)
-		cpufreq_thermal_reduction_pctg[i] = 0;
+	for (i = 0; i < nr_cpu_ids; i++)
+		if (cpu_present(i))
+			per_cpu(cpufreq_thermal_reduction_pctg, i) = 0;
 
 	i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
 				      CPUFREQ_POLICY_NOTIFIER);
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 35a26a3e5f68..d3575f5ec6d2 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -118,9 +118,11 @@ static void handle_update(struct work_struct *work);
 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
 static struct srcu_notifier_head cpufreq_transition_notifier_list;
 
+static bool init_cpufreq_transition_notifier_list_called;
 static int __init init_cpufreq_transition_notifier_list(void)
 {
 	srcu_init_notifier_head(&cpufreq_transition_notifier_list);
+	init_cpufreq_transition_notifier_list_called = true;
 	return 0;
 }
 pure_initcall(init_cpufreq_transition_notifier_list);
@@ -216,7 +218,7 @@ static void cpufreq_debug_disable_ratelimit(void)
 }
 
 void cpufreq_debug_printk(unsigned int type, const char *prefix,
-							const char *fmt, ...)
+			const char *fmt, ...)
 {
 	char s[256];
 	va_list args;
@@ -378,7 +380,7 @@ static struct cpufreq_governor *__find_governor(const char *str_governor)
 /**
  * cpufreq_parse_governor - parse a governor string
  */
-static int cpufreq_parse_governor (char *str_governor, unsigned int *policy,
+static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
 				struct cpufreq_governor **governor)
 {
 	int err = -EINVAL;
@@ -446,7 +448,7 @@ extern struct sysdev_class cpu_sysdev_class;
 
 #define show_one(file_name, object)			\
 static ssize_t show_##file_name				\
-(struct cpufreq_policy * policy, char *buf)		\
+(struct cpufreq_policy *policy, char *buf)		\
 {							\
 	return sprintf (buf, "%u\n", policy->object);	\
 }
@@ -465,7 +467,7 @@ static int __cpufreq_set_policy(struct cpufreq_policy *data,
  */
 #define store_one(file_name, object)			\
 static ssize_t store_##file_name					\
-(struct cpufreq_policy * policy, const char *buf, size_t count)		\
+(struct cpufreq_policy *policy, const char *buf, size_t count)		\
 {									\
 	unsigned int ret = -EINVAL;					\
 	struct cpufreq_policy new_policy;				\
@@ -490,8 +492,8 @@ store_one(scaling_max_freq,max);
 /**
  * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
  */
-static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy,
-							char *buf)
+static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
+					char *buf)
 {
 	unsigned int cur_freq = __cpufreq_get(policy->cpu);
 	if (!cur_freq)
@@ -503,8 +505,7 @@ static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy,
 /**
  * show_scaling_governor - show the current policy for the specified CPU
  */
-static ssize_t show_scaling_governor (struct cpufreq_policy * policy,
-							char *buf)
+static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
 {
 	if(policy->policy == CPUFREQ_POLICY_POWERSAVE)
 		return sprintf(buf, "powersave\n");
@@ -519,8 +520,8 @@ static ssize_t show_scaling_governor (struct cpufreq_policy * policy,
 /**
  * store_scaling_governor - store policy for the specified CPU
  */
-static ssize_t store_scaling_governor (struct cpufreq_policy * policy,
-				       const char *buf, size_t count)
+static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
+					const char *buf, size_t count)
 {
 	unsigned int ret = -EINVAL;
 	char	str_governor[16];
@@ -554,7 +555,7 @@ static ssize_t store_scaling_governor (struct cpufreq_policy * policy,
 /**
  * show_scaling_driver - show the cpufreq driver currently loaded
  */
-static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf)
+static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
 {
 	return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
 }
@@ -562,8 +563,8 @@ static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf)
 /**
  * show_scaling_available_governors - show the available CPUfreq governors
  */
-static ssize_t show_scaling_available_governors (struct cpufreq_policy *policy,
-				char *buf)
+static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
+						char *buf)
 {
 	ssize_t i = 0;
 	struct cpufreq_governor *t;
@@ -585,7 +586,7 @@ out:
 /**
  * show_affected_cpus - show the CPUs affected by each transition
  */
-static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf)
+static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
 {
 	ssize_t i = 0;
 	unsigned int cpu;
@@ -602,7 +603,7 @@ static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf)
 }
 
 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
-		const char *buf, size_t count)
+					const char *buf, size_t count)
 {
 	unsigned int freq = 0;
 	unsigned int ret;
@@ -651,7 +652,7 @@ define_one_rw(scaling_max_freq);
 define_one_rw(scaling_governor);
 define_one_rw(scaling_setspeed);
 
-static struct attribute * default_attrs[] = {
+static struct attribute *default_attrs[] = {
 	&cpuinfo_min_freq.attr,
 	&cpuinfo_max_freq.attr,
 	&scaling_min_freq.attr,
@@ -667,10 +668,10 @@ static struct attribute * default_attrs[] = {
 #define to_policy(k) container_of(k,struct cpufreq_policy,kobj)
 #define to_attr(a) container_of(a,struct freq_attr,attr)
 
-static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf)
+static ssize_t show(struct kobject *kobj, struct attribute *attr ,char *buf)
 {
-	struct cpufreq_policy * policy = to_policy(kobj);
-	struct freq_attr * fattr = to_attr(attr);
+	struct cpufreq_policy *policy = to_policy(kobj);
+	struct freq_attr *fattr = to_attr(attr);
 	ssize_t ret = -EINVAL;
 	policy = cpufreq_cpu_get(policy->cpu);
 	if (!policy)
@@ -691,11 +692,11 @@ no_policy:
 	return ret;
 }
 
-static ssize_t store(struct kobject * kobj, struct attribute * attr,
-		     const char * buf, size_t count)
+static ssize_t store(struct kobject *kobj, struct attribute *attr,
+		     const char *buf, size_t count)
 {
-	struct cpufreq_policy * policy = to_policy(kobj);
-	struct freq_attr * fattr = to_attr(attr);
+	struct cpufreq_policy *policy = to_policy(kobj);
+	struct freq_attr *fattr = to_attr(attr);
 	ssize_t ret = -EINVAL;
 	policy = cpufreq_cpu_get(policy->cpu);
 	if (!policy)
@@ -716,9 +717,9 @@ no_policy:
 	return ret;
 }
 
-static void cpufreq_sysfs_release(struct kobject * kobj)
+static void cpufreq_sysfs_release(struct kobject *kobj)
 {
-	struct cpufreq_policy * policy = to_policy(kobj);
+	struct cpufreq_policy *policy = to_policy(kobj);
 	dprintk("last reference is dropped\n");
 	complete(&policy->kobj_unregister);
 }
@@ -740,7 +741,7 @@ static struct kobj_type ktype_cpufreq = {
  *
  * Adds the cpufreq interface for a CPU device.
  */
-static int cpufreq_add_dev (struct sys_device * sys_dev)
+static int cpufreq_add_dev(struct sys_device *sys_dev)
 {
 	unsigned int cpu = sys_dev->id;
 	int ret = 0;
@@ -800,7 +801,6 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 	ret = cpufreq_driver->init(policy);
 	if (ret) {
 		dprintk("initialization failed\n");
-		unlock_policy_rwsem_write(cpu);
 		goto err_out;
 	}
 	policy->user_policy.min = policy->cpuinfo.min_freq;
@@ -823,7 +823,7 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 		/* check for existing affected CPUs.  They may not be aware
 		 * of it due to CPU Hotplug.
 		 */
-		managed_policy = cpufreq_cpu_get(j);
+		managed_policy = cpufreq_cpu_get(j);		// FIXME: Where is this released?  What about error paths?
 		if (unlikely(managed_policy)) {
 
 			/* Set proper policy_cpu */
@@ -842,14 +842,11 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 			ret = sysfs_create_link(&sys_dev->kobj,
 						&managed_policy->kobj,
 						"cpufreq");
-			if (ret) {
-				unlock_policy_rwsem_write(cpu);
+			if (ret)
 				goto err_out_driver_exit;
-			}
 
 			cpufreq_debug_enable_ratelimit();
 			ret = 0;
-			unlock_policy_rwsem_write(cpu);
 			goto err_out_driver_exit; /* call driver->exit() */
 		}
 	}
@@ -859,33 +856,26 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 	/* prepare interface data */
 	ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj,
 				   "cpufreq");
-	if (ret) {
-		unlock_policy_rwsem_write(cpu);
+	if (ret)
 		goto err_out_driver_exit;
-	}
+
 	/* set up files for this cpu device */
 	drv_attr = cpufreq_driver->attr;
 	while ((drv_attr) && (*drv_attr)) {
 		ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
-		if (ret) {
-			unlock_policy_rwsem_write(cpu);
+		if (ret)
 			goto err_out_driver_exit;
-		}
 		drv_attr++;
 	}
-	if (cpufreq_driver->get){
+	if (cpufreq_driver->get) {
 		ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
-		if (ret) {
-			unlock_policy_rwsem_write(cpu);
+		if (ret)
 			goto err_out_driver_exit;
-		}
 	}
-	if (cpufreq_driver->target){
+	if (cpufreq_driver->target) {
 		ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
-		if (ret) {
-			unlock_policy_rwsem_write(cpu);
+		if (ret)
 			goto err_out_driver_exit;
-		}
 	}
 
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
@@ -907,10 +897,8 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 		cpu_sys_dev = get_cpu_sysdev(j);
 		ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj,
 					"cpufreq");
-		if (ret) {
-			unlock_policy_rwsem_write(cpu);
+		if (ret)
 			goto err_out_unregister;
-		}
 	}
 
 	policy->governor = NULL; /* to assure that the starting sequence is
@@ -950,6 +938,7 @@ err_out_driver_exit:
 		cpufreq_driver->exit(policy);
 
 err_out:
+	unlock_policy_rwsem_write(cpu);
 	kfree(policy);
 
 nomem_out:
@@ -967,7 +956,7 @@ module_out:
  * Caller should already have policy_rwsem in write mode for this CPU.
  * This routine frees the rwsem before returning.
  */
-static int __cpufreq_remove_dev (struct sys_device * sys_dev)
+static int __cpufreq_remove_dev(struct sys_device *sys_dev)
 {
 	unsigned int cpu = sys_dev->id;
 	unsigned long flags;
@@ -1071,7 +1060,7 @@ static int __cpufreq_remove_dev (struct sys_device * sys_dev)
 }
 
 
-static int cpufreq_remove_dev (struct sys_device * sys_dev)
+static int cpufreq_remove_dev(struct sys_device *sys_dev)
 {
 	unsigned int cpu = sys_dev->id;
 	int retval;
@@ -1138,7 +1127,7 @@ unsigned int cpufreq_quick_get(unsigned int cpu)
 		cpufreq_cpu_put(policy);
 	}
 
-	return (ret_freq);
+	return ret_freq;
 }
 EXPORT_SYMBOL(cpufreq_quick_get);
 
@@ -1149,7 +1138,7 @@ static unsigned int __cpufreq_get(unsigned int cpu)
 	unsigned int ret_freq = 0;
 
 	if (!cpufreq_driver->get)
-		return (ret_freq);
+		return ret_freq;
 
 	ret_freq = cpufreq_driver->get(cpu);
 
@@ -1163,7 +1152,7 @@ static unsigned int __cpufreq_get(unsigned int cpu)
 		}
 	}
 
-	return (ret_freq);
+	return ret_freq;
 }
 
 /**
@@ -1190,7 +1179,7 @@ unsigned int cpufreq_get(unsigned int cpu)
 out_policy:
 	cpufreq_cpu_put(policy);
 out:
-	return (ret_freq);
+	return ret_freq;
 }
 EXPORT_SYMBOL(cpufreq_get);
 
@@ -1199,7 +1188,7 @@ EXPORT_SYMBOL(cpufreq_get);
  *	cpufreq_suspend - let the low level driver prepare for suspend
  */
 
-static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
+static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg)
 {
 	int cpu = sysdev->id;
 	int ret = 0;
@@ -1221,22 +1210,18 @@ static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
 		return -EINVAL;
 
 	/* only handle each CPU group once */
-	if (unlikely(cpu_policy->cpu != cpu)) {
-		cpufreq_cpu_put(cpu_policy);
-		return 0;
-	}
+	if (unlikely(cpu_policy->cpu != cpu))
+		goto out;
 
 	if (cpufreq_driver->suspend) {
 		ret = cpufreq_driver->suspend(cpu_policy, pmsg);
 		if (ret) {
 			printk(KERN_ERR "cpufreq: suspend failed in ->suspend "
 					"step on CPU %u\n", cpu_policy->cpu);
-			cpufreq_cpu_put(cpu_policy);
-			return ret;
+			goto out;
 		}
 	}
 
-
 	if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)
 		goto out;
 
@@ -1270,7 +1255,7 @@ static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
 
 out:
 	cpufreq_cpu_put(cpu_policy);
-	return 0;
+	return ret;
 }
 
 /**
@@ -1281,7 +1266,7 @@ out:
  *	3.) schedule call cpufreq_update_policy() ASAP as interrupts are
  *	    restored.
  */
-static int cpufreq_resume(struct sys_device * sysdev)
+static int cpufreq_resume(struct sys_device *sysdev)
 {
 	int cpu = sysdev->id;
 	int ret = 0;
@@ -1302,18 +1287,15 @@ static int cpufreq_resume(struct sys_device * sysdev)
 		return -EINVAL;
 
 	/* only handle each CPU group once */
-	if (unlikely(cpu_policy->cpu != cpu)) {
-		cpufreq_cpu_put(cpu_policy);
-		return 0;
-	}
+	if (unlikely(cpu_policy->cpu != cpu))
+		goto fail;
 
 	if (cpufreq_driver->resume) {
 		ret = cpufreq_driver->resume(cpu_policy);
 		if (ret) {
 			printk(KERN_ERR "cpufreq: resume failed in ->resume "
 					"step on CPU %u\n", cpu_policy->cpu);
-			cpufreq_cpu_put(cpu_policy);
-			return ret;
+			goto fail;
 		}
 	}
 
@@ -1353,6 +1335,7 @@ static int cpufreq_resume(struct sys_device * sysdev)
 
 out:
 	schedule_work(&cpu_policy->update);
+fail:
 	cpufreq_cpu_put(cpu_policy);
 	return ret;
 }
@@ -1386,6 +1369,8 @@ int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
 {
 	int ret;
 
+	WARN_ON(!init_cpufreq_transition_notifier_list_called);
+
 	switch (list) {
 	case CPUFREQ_TRANSITION_NOTIFIER:
 		ret = srcu_notifier_chain_register(
@@ -1848,7 +1833,7 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
 		cpufreq_debug_enable_ratelimit();
 	}
 
-	return (ret);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
 
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 070421a5480e..ef09e069433b 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -114,7 +114,7 @@ show_trans_table(struct cpufreq_policy *policy, char *buf)
 				stat->freq_table[i]);
 	}
 	if (len >= PAGE_SIZE)
-		return len;
+		return PAGE_SIZE;
 
 	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
 
@@ -131,8 +131,12 @@ show_trans_table(struct cpufreq_policy *policy, char *buf)
 			len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
 					stat->trans_table[i*stat->max_state+j]);
 		}
+		if (len >= PAGE_SIZE)
+			break;
 		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
 	}
+	if (len >= PAGE_SIZE)
+		return PAGE_SIZE;
 	return len;
 }
 CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);