UBUNTU: Ubuntu-4.10.0-37.41

[mirror_ubuntu-zesty-kernel.git] / drivers / devfreq / devfreq.c

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 47206a21bb901f424c4e331c9db6eaedef69d93d..416736e2b8034a9fe16d0ba8e6240e0fe2d852b7 100644 (file)
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -130,7 +130,7 @@ static void devfreq_set_freq_table(struct devfreq *devfreq)
  * @devfreq:   the devfreq instance
  * @freq:      the update target frequency
  */
-static int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
+int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
 {
        int lev, prev_lev, ret = 0;
        unsigned long cur_time;
@@ -166,6 +166,7 @@ out:
        devfreq->last_stat_updated = cur_time;
        return ret;
 }
+EXPORT_SYMBOL(devfreq_update_status);
 
 /**
  * find_devfreq_governor() - find devfreq governor from name
@@ -939,6 +940,9 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
        if (df->governor == governor) {
                ret = 0;
                goto out;
+       } else if (df->governor->immutable || governor->immutable) {
+               ret = -EINVAL;
+               goto out;
        }
 
        if (df->governor) {
@@ -968,13 +972,33 @@ static ssize_t available_governors_show(struct device *d,
                                        struct device_attribute *attr,
                                        char *buf)
 {
-       struct devfreq_governor *tmp_governor;
+       struct devfreq *df = to_devfreq(d);
        ssize_t count = 0;
 
        mutex_lock(&devfreq_list_lock);
-       list_for_each_entry(tmp_governor, &devfreq_governor_list, node)
-               count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
-                                  "%s ", tmp_governor->name);
+
+       /*
+        * The devfreq with immutable governor (e.g., passive) shows
+        * only own governor.
+        */
+       if (df->governor->immutable) {
+               count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
+                                  "%s ", df->governor_name);
+       /*
+        * The devfreq device shows the registered governor except for
+        * immutable governors such as passive governor .
+        */
+       } else {
+               struct devfreq_governor *governor;
+
+               list_for_each_entry(governor, &devfreq_governor_list, node) {
+                       if (governor->immutable)
+                               continue;
+                       count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
+                                          "%s ", governor->name);
+               }
+       }
+
        mutex_unlock(&devfreq_list_lock);
 
        /* Truncate the trailing space */