]> Pileus Git - ~andy/linux/commitdiff
Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq
authorLinus Torvalds <torvalds@woody.linux-foundation.org>
Sat, 17 Nov 2007 02:30:26 +0000 (18:30 -0800)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Sat, 17 Nov 2007 02:30:26 +0000 (18:30 -0800)
* 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

arch/x86/kernel/cpu/cpufreq/powernow-k8.c
arch/x86/kernel/cpu/cpufreq/powernow-k8.h
drivers/cpufreq/cpufreq_conservative.c

index 9c36a53676b770830e1efffb5770788d34ab2ee4..99e1ef9939bec24bc210791eecc6f23f328c24ae 100644 (file)
@@ -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);
 
index 7c4f6e0faed4a555ac599837d347dee7958d4feb..afd2b520d35c6258a25a2bc0f804279b647ae430 100644 (file)
@@ -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
index 4bd33ce8a6f3398a0aa37995582e619c3b938590..1bba99747f5b3da806fea25aa991d3ac151673be 100644 (file)
 #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;
        }