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

* master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] Fix up whitespace in conservative governor.
  [CPUFREQ] Make cpufreq_conservative handle out-of-sync events properly
  [CPUFREQ] architectural pstate driver for powernow-k8

3 files changed, 119 insertions, 144 deletions

diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index 9c36a53676b7..99e1ef9939be 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -46,7 +46,7 @@
 
 #define PFX "powernow-k8: "
 #define BFX PFX "BIOS error: "
-#define VERSION "version 2.00.00"
+#define VERSION "version 2.20.00"
 #include "powernow-k8.h"
 
 /* serialize freq changes  */
@@ -73,33 +73,11 @@ static u32 find_khz_freq_from_fid(u32 fid)
 	return 1000 * find_freq_from_fid(fid);
 }
 
-/* Return a frequency in MHz, given an input fid and did */
-static u32 find_freq_from_fiddid(u32 fid, u32 did)
+static u32 find_khz_freq_from_pstate(struct cpufreq_frequency_table *data, u32 pstate)
 {
-	if (current_cpu_data.x86 == 0x10)
-		return 100 * (fid + 0x10) >> did;
-	else
-		return 100 * (fid + 0x8) >> did;
-}
-
-static u32 find_khz_freq_from_fiddid(u32 fid, u32 did)
-{
-	return 1000 * find_freq_from_fiddid(fid, did);
-}
-
-static u32 find_fid_from_pstate(u32 pstate)
-{
-	u32 hi, lo;
-	rdmsr(MSR_PSTATE_DEF_BASE + pstate, lo, hi);
-	return lo & HW_PSTATE_FID_MASK;
+	return data[pstate].frequency;
 }
 
-static u32 find_did_from_pstate(u32 pstate)
-{
-	u32 hi, lo;
-	rdmsr(MSR_PSTATE_DEF_BASE + pstate, lo, hi);
-	return (lo & HW_PSTATE_DID_MASK) >> HW_PSTATE_DID_SHIFT;
-}
 
 /* Return the vco fid for an input fid
  *
@@ -142,9 +120,7 @@ static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
 	if (cpu_family == CPU_HW_PSTATE) {
 		rdmsr(MSR_PSTATE_STATUS, lo, hi);
 		i = lo & HW_PSTATE_MASK;
-		rdmsr(MSR_PSTATE_DEF_BASE + i, lo, hi);
-		data->currfid = lo & HW_PSTATE_FID_MASK;
-		data->currdid = (lo & HW_PSTATE_DID_MASK) >> HW_PSTATE_DID_SHIFT;
+		data->currpstate = i;
 		return 0;
 	}
 	do {
@@ -295,7 +271,7 @@ static int decrease_vid_code_by_step(struct powernow_k8_data *data, u32 reqvid,
 static int transition_pstate(struct powernow_k8_data *data, u32 pstate)
 {
 	wrmsr(MSR_PSTATE_CTRL, pstate, 0);
-	data->currfid = find_fid_from_pstate(pstate);
+	data->currpstate = pstate;
 	return 0;
 }
 
@@ -845,17 +821,20 @@ err_out:
 static int fill_powernow_table_pstate(struct powernow_k8_data *data, struct cpufreq_frequency_table *powernow_table)
 {
 	int i;
+	u32 hi = 0, lo = 0;
+	rdmsr(MSR_PSTATE_CUR_LIMIT, hi, lo);
+	data->max_hw_pstate = (hi & HW_PSTATE_MAX_MASK) >> HW_PSTATE_MAX_SHIFT;
 
 	for (i = 0; i < data->acpi_data.state_count; i++) {
 		u32 index;
 		u32 hi = 0, lo = 0;
-		u32 fid;
-		u32 did;
 
 		index = data->acpi_data.states[i].control & HW_PSTATE_MASK;
-		if (index > MAX_HW_PSTATE) {
+		if (index > data->max_hw_pstate) {
 			printk(KERN_ERR PFX "invalid pstate %d - bad value %d.\n", i, index);
 			printk(KERN_ERR PFX "Please report to BIOS manufacturer\n");
+			powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
+			continue;
 		}
 		rdmsr(MSR_PSTATE_DEF_BASE + index, lo, hi);
 		if (!(hi & HW_PSTATE_VALID_MASK)) {
@@ -864,22 +843,9 @@ static int fill_powernow_table_pstate(struct powernow_k8_data *data, struct cpuf
 			continue;
 		}
 
-		fid = lo & HW_PSTATE_FID_MASK;
-		did = (lo & HW_PSTATE_DID_MASK) >> HW_PSTATE_DID_SHIFT;
+		powernow_table[i].index = index;
 
-		dprintk("   %d : fid 0x%x, did 0x%x\n", index, fid, did);
-
-		powernow_table[i].index = index | (fid << HW_FID_INDEX_SHIFT) | (did << HW_DID_INDEX_SHIFT);
-
-		powernow_table[i].frequency = find_khz_freq_from_fiddid(fid, did);
-
-		if (powernow_table[i].frequency != (data->acpi_data.states[i].core_frequency * 1000)) {
-			printk(KERN_INFO PFX "invalid freq entries %u kHz vs. %u kHz\n",
-				powernow_table[i].frequency,
-				(unsigned int) (data->acpi_data.states[i].core_frequency * 1000));
-			powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
-			continue;
-		}
+		powernow_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000;
 	}
 	return 0;
 }
@@ -1020,22 +986,18 @@ static int transition_frequency_fidvid(struct powernow_k8_data *data, unsigned i
 /* Take a frequency, and issue the hardware pstate transition command */
 static int transition_frequency_pstate(struct powernow_k8_data *data, unsigned int index)
 {
-	u32 fid = 0;
-	u32 did = 0;
 	u32 pstate = 0;
 	int res, i;
 	struct cpufreq_freqs freqs;
 
 	dprintk("cpu %d transition to index %u\n", smp_processor_id(), index);
 
-	/* get fid did for hardware pstate transition */
+	/* get MSR index for hardware pstate transition */
 	pstate = index & HW_PSTATE_MASK;
-	if (pstate > MAX_HW_PSTATE)
+	if (pstate > data->max_hw_pstate)
 		return 0;
-	fid = (index & HW_FID_INDEX_MASK) >> HW_FID_INDEX_SHIFT;
-	did = (index & HW_DID_INDEX_MASK) >> HW_DID_INDEX_SHIFT;
-	freqs.old = find_khz_freq_from_fiddid(data->currfid, data->currdid);
-	freqs.new = find_khz_freq_from_fiddid(fid, did);
+	freqs.old = find_khz_freq_from_pstate(data->powernow_table, data->currpstate);
+	freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate);
 
 	for_each_cpu_mask(i, *(data->available_cores)) {
 		freqs.cpu = i;
@@ -1043,9 +1005,7 @@ static int transition_frequency_pstate(struct powernow_k8_data *data, unsigned i
 	}
 
 	res = transition_pstate(data, pstate);
-	data->currfid = find_fid_from_pstate(pstate);
-	data->currdid = find_did_from_pstate(pstate);
-	freqs.new = find_khz_freq_from_fiddid(data->currfid, data->currdid);
+	freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate);
 
 	for_each_cpu_mask(i, *(data->available_cores)) {
 		freqs.cpu = i;
@@ -1090,10 +1050,7 @@ static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsi
 	if (query_current_values_with_pending_wait(data))
 		goto err_out;
 
-	if (cpu_family == CPU_HW_PSTATE)
-		dprintk("targ: curr fid 0x%x, did 0x%x\n",
-			data->currfid, data->currdid);
-	else {
+	if (cpu_family != CPU_HW_PSTATE) {
 		dprintk("targ: curr fid 0x%x, vid 0x%x\n",
 		data->currfid, data->currvid);
 
@@ -1124,7 +1081,7 @@ static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsi
 	mutex_unlock(&fidvid_mutex);
 
 	if (cpu_family == CPU_HW_PSTATE)
-		pol->cur = find_khz_freq_from_fiddid(data->currfid, data->currdid);
+		pol->cur = find_khz_freq_from_pstate(data->powernow_table, newstate);
 	else
 		pol->cur = find_khz_freq_from_fid(data->currfid);
 	ret = 0;
@@ -1223,7 +1180,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
 	    + (3 * (1 << data->irt) * 10)) * 1000;
 
 	if (cpu_family == CPU_HW_PSTATE)
-		pol->cur = find_khz_freq_from_fiddid(data->currfid, data->currdid);
+		pol->cur = find_khz_freq_from_pstate(data->powernow_table, data->currpstate);
 	else
 		pol->cur = find_khz_freq_from_fid(data->currfid);
 	dprintk("policy current frequency %d kHz\n", pol->cur);
@@ -1240,8 +1197,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
 	cpufreq_frequency_table_get_attr(data->powernow_table, pol->cpu);
 
 	if (cpu_family == CPU_HW_PSTATE)
-		dprintk("cpu_init done, current fid 0x%x, did 0x%x\n",
-			data->currfid, data->currdid);
+		dprintk("cpu_init done, current pstate 0x%x\n", data->currpstate);
 	else
 		dprintk("cpu_init done, current fid 0x%x, vid 0x%x\n",
 			data->currfid, data->currvid);
@@ -1297,7 +1253,7 @@ static unsigned int powernowk8_get (unsigned int cpu)
 		goto out;
 
 	if (cpu_family == CPU_HW_PSTATE)
-		khz = find_khz_freq_from_fiddid(data->currfid, data->currdid);
+		khz = find_khz_freq_from_pstate(data->powernow_table, data->currpstate);
 	else
 		khz = find_khz_freq_from_fid(data->currfid);
 
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
index 7c4f6e0faed4..afd2b520d35c 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
@@ -10,6 +10,7 @@ struct powernow_k8_data {
 
 	u32 numps;  /* number of p-states */
 	u32 batps;  /* number of p-states supported on battery */
+	u32 max_hw_pstate; /* maximum legal hardware pstate */
 
 	/* these values are constant when the PSB is used to determine
 	 * vid/fid pairings, but are modified during the ->target() call
@@ -21,8 +22,8 @@ struct powernow_k8_data {
 	u32 plllock; /* pll lock time, units 1 us */
         u32 exttype; /* extended interface = 1 */
 
-	/* keep track of the current fid / vid or did */
-	u32 currvid, currfid, currdid;
+	/* keep track of the current fid / vid or pstate */
+	u32 currvid, currfid, currpstate;
 
 	/* the powernow_table includes all frequency and vid/fid pairings:
 	 * fid are the lower 8 bits of the index, vid are the upper 8 bits.
@@ -87,23 +88,14 @@ struct powernow_k8_data {
 
 /* Hardware Pstate _PSS and MSR definitions */
 #define USE_HW_PSTATE		0x00000080
-#define HW_PSTATE_FID_MASK 	0x0000003f
-#define HW_PSTATE_DID_MASK 	0x000001c0
-#define HW_PSTATE_DID_SHIFT 	6
 #define HW_PSTATE_MASK 		0x00000007
 #define HW_PSTATE_VALID_MASK 	0x80000000
-#define HW_FID_INDEX_SHIFT	8
-#define HW_FID_INDEX_MASK	0x0000ff00
-#define HW_DID_INDEX_SHIFT	16
-#define HW_DID_INDEX_MASK	0x00ff0000
-#define HW_WATTS_MASK		0xff
-#define HW_PWR_DVR_MASK		0x300
-#define HW_PWR_DVR_SHIFT	8
-#define HW_PWR_MAX_MULT		3
-#define MAX_HW_PSTATE		8	/* hw pstate supports up to 8 */
+#define HW_PSTATE_MAX_MASK	0x000000f0
+#define HW_PSTATE_MAX_SHIFT	4
 #define MSR_PSTATE_DEF_BASE 	0xc0010064 /* base of Pstate MSRs */
 #define MSR_PSTATE_STATUS 	0xc0010063 /* Pstate Status MSR */
 #define MSR_PSTATE_CTRL 	0xc0010062 /* Pstate control MSR */
+#define MSR_PSTATE_CUR_LIMIT	0xc0010061 /* pstate current limit MSR */
 
 /* define the two driver architectures */
 #define CPU_OPTERON 0
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index 4bd33ce8a6f3..1bba99747f5b 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -37,17 +37,17 @@
 #define DEF_FREQUENCY_UP_THRESHOLD		(80)
 #define DEF_FREQUENCY_DOWN_THRESHOLD		(20)
 
-/* 
- * The polling frequency of this governor depends on the capability of 
+/*
+ * The polling frequency of this governor depends on the capability of
  * the processor. Default polling frequency is 1000 times the transition
- * latency of the processor. The governor will work on any processor with 
- * transition latency <= 10mS, using appropriate sampling 
+ * latency of the processor. The governor will work on any processor with
+ * transition latency <= 10mS, using appropriate sampling
  * rate.
  * For CPUs with transition latency > 10mS (mostly drivers
  * with CPUFREQ_ETERNAL), this governor will not work.
  * All times here are in uS.
  */
-static unsigned int 				def_sampling_rate;
+static unsigned int def_sampling_rate;
 #define MIN_SAMPLING_RATE_RATIO			(2)
 /* for correct statistics, we need at least 10 ticks between each measure */
 #define MIN_STAT_SAMPLING_RATE			\
@@ -63,12 +63,12 @@ static unsigned int 				def_sampling_rate;
 static void do_dbs_timer(struct work_struct *work);
 
 struct cpu_dbs_info_s {
-	struct cpufreq_policy 	*cur_policy;
-	unsigned int 		prev_cpu_idle_up;
-	unsigned int 		prev_cpu_idle_down;
-	unsigned int 		enable;
-	unsigned int		down_skip;
-	unsigned int		requested_freq;
+	struct cpufreq_policy *cur_policy;
+	unsigned int prev_cpu_idle_up;
+	unsigned int prev_cpu_idle_down;
+	unsigned int enable;
+	unsigned int down_skip;
+	unsigned int requested_freq;
 };
 static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
 
@@ -82,24 +82,24 @@ static unsigned int dbs_enable;	/* number of CPUs using this policy */
  * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock
  * is recursive for the same process. -Venki
  */
-static DEFINE_MUTEX 	(dbs_mutex);
+static DEFINE_MUTEX (dbs_mutex);
 static DECLARE_DELAYED_WORK(dbs_work, do_dbs_timer);
 
 struct dbs_tuners {
-	unsigned int 		sampling_rate;
-	unsigned int		sampling_down_factor;
-	unsigned int		up_threshold;
-	unsigned int		down_threshold;
-	unsigned int		ignore_nice;
-	unsigned int		freq_step;
+	unsigned int sampling_rate;
+	unsigned int sampling_down_factor;
+	unsigned int up_threshold;
+	unsigned int down_threshold;
+	unsigned int ignore_nice;
+	unsigned int freq_step;
 };
 
 static struct dbs_tuners dbs_tuners_ins = {
-	.up_threshold 		= DEF_FREQUENCY_UP_THRESHOLD,
-	.down_threshold 	= DEF_FREQUENCY_DOWN_THRESHOLD,
-	.sampling_down_factor 	= DEF_SAMPLING_DOWN_FACTOR,
-	.ignore_nice		= 0,
-	.freq_step		= 5,
+	.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
+	.down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD,
+	.sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
+	.ignore_nice = 0,
+	.freq_step = 5,
 };
 
 static inline unsigned int get_cpu_idle_time(unsigned int cpu)
@@ -109,13 +109,34 @@ static inline unsigned int get_cpu_idle_time(unsigned int cpu)
 	if (dbs_tuners_ins.ignore_nice)
 		add_nice = kstat_cpu(cpu).cpustat.nice;
 
-	ret = 	kstat_cpu(cpu).cpustat.idle +
+	ret = kstat_cpu(cpu).cpustat.idle +
 		kstat_cpu(cpu).cpustat.iowait +
 		add_nice;
 
 	return ret;
 }
 
+/* keep track of frequency transitions */
+static int
+dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
+		     void *data)
+{
+	struct cpufreq_freqs *freq = data;
+	struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info,
+							freq->cpu);
+
+	if (!this_dbs_info->enable)
+		return 0;
+
+	this_dbs_info->requested_freq = freq->new;
+
+	return 0;
+}
+
+static struct notifier_block dbs_cpufreq_notifier_block = {
+	.notifier_call = dbs_cpufreq_notifier
+};
+
 /************************** sysfs interface ************************/
 static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf)
 {
@@ -127,8 +148,8 @@ static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
 	return sprintf (buf, "%u\n", MIN_SAMPLING_RATE);
 }
 
-#define define_one_ro(_name) 					\
-static struct freq_attr _name =  				\
+#define define_one_ro(_name)				\
+static struct freq_attr _name =				\
 __ATTR(_name, 0444, show_##_name, NULL)
 
 define_one_ro(sampling_rate_max);
@@ -148,7 +169,7 @@ show_one(down_threshold, down_threshold);
 show_one(ignore_nice_load, ignore_nice);
 show_one(freq_step, freq_step);
 
-static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused, 
+static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
 		const char *buf, size_t count)
 {
 	unsigned int input;
@@ -164,7 +185,7 @@ static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
 	return count;
 }
 
-static ssize_t store_sampling_rate(struct cpufreq_policy *unused, 
+static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
 		const char *buf, size_t count)
 {
 	unsigned int input;
@@ -183,7 +204,7 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
 	return count;
 }
 
-static ssize_t store_up_threshold(struct cpufreq_policy *unused, 
+static ssize_t store_up_threshold(struct cpufreq_policy *unused,
 		const char *buf, size_t count)
 {
 	unsigned int input;
@@ -202,7 +223,7 @@ static ssize_t store_up_threshold(struct cpufreq_policy *unused,
 	return count;
 }
 
-static ssize_t store_down_threshold(struct cpufreq_policy *unused, 
+static ssize_t store_down_threshold(struct cpufreq_policy *unused,
 		const char *buf, size_t count)
 {
 	unsigned int input;
@@ -228,16 +249,16 @@ static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy,
 	int ret;
 
 	unsigned int j;
-	
-	ret = sscanf (buf, "%u", &input);
-	if ( ret != 1 )
+
+	ret = sscanf(buf, "%u", &input);
+	if (ret != 1)
 		return -EINVAL;
 
-	if ( input > 1 )
+	if (input > 1)
 		input = 1;
-	
+
 	mutex_lock(&dbs_mutex);
-	if ( input == dbs_tuners_ins.ignore_nice ) { /* nothing to do */
+	if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */
 		mutex_unlock(&dbs_mutex);
 		return count;
 	}
@@ -261,14 +282,14 @@ static ssize_t store_freq_step(struct cpufreq_policy *policy,
 	unsigned int input;
 	int ret;
 
-	ret = sscanf (buf, "%u", &input);
+	ret = sscanf(buf, "%u", &input);
 
-	if ( ret != 1 )
+	if (ret != 1)
 		return -EINVAL;
 
-	if ( input > 100 )
+	if (input > 100)
 		input = 100;
-	
+
 	/* no need to test here if freq_step is zero as the user might actually
 	 * want this, they would be crazy though :) */
 	mutex_lock(&dbs_mutex);
@@ -322,18 +343,18 @@ static void dbs_check_cpu(int cpu)
 
 	policy = this_dbs_info->cur_policy;
 
-	/* 
-	 * The default safe range is 20% to 80% 
+	/*
+	 * The default safe range is 20% to 80%
 	 * Every sampling_rate, we check
-	 * 	- If current idle time is less than 20%, then we try to 
-	 * 	  increase frequency
+	 *	- If current idle time is less than 20%, then we try to
+	 *	  increase frequency
 	 * Every sampling_rate*sampling_down_factor, we check
-	 * 	- If current idle time is more than 80%, then we try to
-	 * 	  decrease frequency
+	 *	- If current idle time is more than 80%, then we try to
+	 *	  decrease frequency
 	 *
-	 * Any frequency increase takes it to the maximum frequency. 
-	 * Frequency reduction happens at minimum steps of 
-	 * 5% (default) of max_frequency 
+	 * Any frequency increase takes it to the maximum frequency.
+	 * Frequency reduction happens at minimum steps of
+	 * 5% (default) of max_frequency
 	 */
 
 	/* Check for frequency increase */
@@ -361,13 +382,13 @@ static void dbs_check_cpu(int cpu)
 		/* if we are already at full speed then break out early */
 		if (this_dbs_info->requested_freq == policy->max)
 			return;
-		
+
 		freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100;
 
 		/* max freq cannot be less than 100. But who knows.... */
 		if (unlikely(freq_step == 0))
 			freq_step = 5;
-		
+
 		this_dbs_info->requested_freq += freq_step;
 		if (this_dbs_info->requested_freq > policy->max)
 			this_dbs_info->requested_freq = policy->max;
@@ -427,15 +448,15 @@ static void dbs_check_cpu(int cpu)
 }
 
 static void do_dbs_timer(struct work_struct *work)
-{ 
+{
 	int i;
 	mutex_lock(&dbs_mutex);
 	for_each_online_cpu(i)
 		dbs_check_cpu(i);
-	schedule_delayed_work(&dbs_work, 
+	schedule_delayed_work(&dbs_work,
 			usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
 	mutex_unlock(&dbs_mutex);
-} 
+}
 
 static inline void dbs_timer_init(void)
 {
@@ -462,13 +483,12 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 
 	switch (event) {
 	case CPUFREQ_GOV_START:
-		if ((!cpu_online(cpu)) || 
-		    (!policy->cur))
+		if ((!cpu_online(cpu)) || (!policy->cur))
 			return -EINVAL;
 
 		if (this_dbs_info->enable) /* Already enabled */
 			break;
-		 
+
 		mutex_lock(&dbs_mutex);
 
 		rc = sysfs_create_group(&policy->kobj, &dbs_attr_group);
@@ -481,7 +501,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 			struct cpu_dbs_info_s *j_dbs_info;
 			j_dbs_info = &per_cpu(cpu_dbs_info, j);
 			j_dbs_info->cur_policy = policy;
-		
+
 			j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(cpu);
 			j_dbs_info->prev_cpu_idle_down
 				= j_dbs_info->prev_cpu_idle_up;
@@ -511,8 +531,11 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 			dbs_tuners_ins.sampling_rate = def_sampling_rate;
 
 			dbs_timer_init();
+			cpufreq_register_notifier(
+					&dbs_cpufreq_notifier_block,
+					CPUFREQ_TRANSITION_NOTIFIER);
 		}
-		
+
 		mutex_unlock(&dbs_mutex);
 		break;
 
@@ -525,9 +548,13 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 		 * Stop the timerschedule work, when this governor
 		 * is used for first time
 		 */
-		if (dbs_enable == 0) 
+		if (dbs_enable == 0) {
 			dbs_timer_exit();
-		
+			cpufreq_unregister_notifier(
+					&dbs_cpufreq_notifier_block,
+					CPUFREQ_TRANSITION_NOTIFIER);
+		}
+
 		mutex_unlock(&dbs_mutex);
 
 		break;
@@ -537,11 +564,11 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 		if (policy->max < this_dbs_info->cur_policy->cur)
 			__cpufreq_driver_target(
 					this_dbs_info->cur_policy,
-				       	policy->max, CPUFREQ_RELATION_H);
+					policy->max, CPUFREQ_RELATION_H);
 		else if (policy->min > this_dbs_info->cur_policy->cur)
 			__cpufreq_driver_target(
 					this_dbs_info->cur_policy,
-				       	policy->min, CPUFREQ_RELATION_L);
+					policy->min, CPUFREQ_RELATION_L);
 		mutex_unlock(&dbs_mutex);
 		break;
 	}