1 files changed, 59 insertions, 31 deletions

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 0ae3de76833b..6b6991f0e873 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -29,6 +29,9 @@
 #include <linux/of.h>
 #include "governor.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/devfreq.h>
+
 static struct class *devfreq_class;
 
 /*
@@ -228,7 +231,7 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
  * if is not found. This can happen when both drivers (the governor driver
  * and the driver that call devfreq_add_device) are built as modules.
  * devfreq_list_lock should be held by the caller. Returns the matched
- * governor's pointer.
+ * governor's pointer or an error pointer.
  */
 static struct devfreq_governor *try_then_request_governor(const char *name)
 {
@@ -254,7 +257,7 @@ static struct devfreq_governor *try_then_request_governor(const char *name)
                 /* Restore previous state before return */
                 mutex_lock(&devfreq_list_lock);
                 if (err)
-                        return NULL;
+                        return ERR_PTR(err);
 
                 governor = find_devfreq_governor(name);
         }
@@ -394,6 +397,8 @@ static void devfreq_monitor(struct work_struct *work)
         queue_delayed_work(devfreq_wq, &devfreq->work,
                                 msecs_to_jiffies(devfreq->profile->polling_ms));
         mutex_unlock(&devfreq->lock);
+
+        trace_devfreq_monitor(devfreq);
 }
 
 /**
@@ -528,7 +533,7 @@ void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay)
                 mutex_lock(&devfreq->lock);
                 if (!devfreq->stop_polling)
                         queue_delayed_work(devfreq_wq, &devfreq->work,
-                              msecs_to_jiffies(devfreq->profile->polling_ms));
+                                msecs_to_jiffies(devfreq->profile->polling_ms));
         }
 out:
         mutex_unlock(&devfreq->lock);
@@ -537,7 +542,7 @@ EXPORT_SYMBOL(devfreq_interval_update);
 
 /**
  * devfreq_notifier_call() - Notify that the device frequency requirements
- *                         has been changed out of devfreq framework.
+ *                           has been changed out of devfreq framework.
  * @nb:         the notifier_block (supposed to be devfreq->nb)
  * @type:       not used
  * @devp:       not used
@@ -651,7 +656,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
                 mutex_unlock(&devfreq->lock);
                 err = set_freq_table(devfreq);
                 if (err < 0)
-                        goto err_out;
+                        goto err_dev;
                 mutex_lock(&devfreq->lock);
         }
 
@@ -683,16 +688,27 @@ struct devfreq *devfreq_add_device(struct device *dev,
                 goto err_out;
         }
 
-        devfreq->trans_table =
-                devm_kzalloc(&devfreq->dev,
-                             array3_size(sizeof(unsigned int),
-                                         devfreq->profile->max_state,
-                                         devfreq->profile->max_state),
-                             GFP_KERNEL);
+        devfreq->trans_table = devm_kzalloc(&devfreq->dev,
+                        array3_size(sizeof(unsigned int),
+                                    devfreq->profile->max_state,
+                                    devfreq->profile->max_state),
+                        GFP_KERNEL);
+        if (!devfreq->trans_table) {
+                mutex_unlock(&devfreq->lock);
+                err = -ENOMEM;
+                goto err_devfreq;
+        }
+
         devfreq->time_in_state = devm_kcalloc(&devfreq->dev,
-                                                devfreq->profile->max_state,
-                                                sizeof(unsigned long),
-                                                GFP_KERNEL);
+                        devfreq->profile->max_state,
+                        sizeof(unsigned long),
+                        GFP_KERNEL);
+        if (!devfreq->time_in_state) {
+                mutex_unlock(&devfreq->lock);
+                err = -ENOMEM;
+                goto err_devfreq;
+        }
+
         devfreq->last_stat_updated = jiffies;
 
         srcu_init_notifier_head(&devfreq->transition_notifier_list);
@@ -726,7 +742,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 
 err_init:
         mutex_unlock(&devfreq_list_lock);
-
+err_devfreq:
         devfreq_remove_device(devfreq);
         devfreq = NULL;
 err_dev:
@@ -1113,7 +1129,7 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
         struct devfreq *df = to_devfreq(dev);
         int ret;
         char str_governor[DEVFREQ_NAME_LEN + 1];
-        struct devfreq_governor *governor;
+        const struct devfreq_governor *governor, *prev_governor;
 
         ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
         if (ret != 1)
@@ -1142,12 +1158,24 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
                         goto out;
                 }
         }
+        prev_governor = df->governor;
         df->governor = governor;
         strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN);
         ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
-        if (ret)
+        if (ret) {
                 dev_warn(dev, "%s: Governor %s not started(%d)\n",
                          __func__, df->governor->name, ret);
+                df->governor = prev_governor;
+                strncpy(df->governor_name, prev_governor->name,
+                        DEVFREQ_NAME_LEN);
+                ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
+                if (ret) {
+                        dev_err(dev,
+                                "%s: reverting to Governor %s failed (%d)\n",
+                                __func__, df->governor_name, ret);
+                        df->governor = NULL;
+                }
+        }
 out:
         mutex_unlock(&devfreq_list_lock);
 
@@ -1172,7 +1200,7 @@ static ssize_t available_governors_show(struct device *d,
          */
         if (df->governor->immutable) {
                 count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
-                                   "%s ", df->governor_name);
+                                  "%s ", df->governor_name);
         /*
          * The devfreq device shows the registered governor except for
          * immutable governors such as passive governor .
@@ -1485,8 +1513,8 @@ EXPORT_SYMBOL(devfreq_recommended_opp);
 
 /**
  * devfreq_register_opp_notifier() - Helper function to get devfreq notified
- *                                 for any changes in the OPP availability
- *                                 changes
+ *                                   for any changes in the OPP availability
+ *                                   changes
  * @dev:        The devfreq user device. (parent of devfreq)
  * @devfreq:    The devfreq object.
  */
@@ -1498,8 +1526,8 @@ EXPORT_SYMBOL(devfreq_register_opp_notifier);
 
 /**
  * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq
- *                                   notified for any changes in the OPP
- *                                   availability changes anymore.
+ *                                     notified for any changes in the OPP
+ *                                     availability changes anymore.
  * @dev:        The devfreq user device. (parent of devfreq)
  * @devfreq:    The devfreq object.
  *
@@ -1518,8 +1546,8 @@ static void devm_devfreq_opp_release(struct device *dev, void *res)
 }
 
 /**
- * devm_ devfreq_register_opp_notifier()
- *              - Resource-managed devfreq_register_opp_notifier()
+ * devm_devfreq_register_opp_notifier() - Resource-managed
+ *                                        devfreq_register_opp_notifier()
  * @dev:        The devfreq user device. (parent of devfreq)
  * @devfreq:    The devfreq object.
  */
@@ -1547,8 +1575,8 @@ int devm_devfreq_register_opp_notifier(struct device *dev,
 EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
 
 /**
- * devm_devfreq_unregister_opp_notifier()
- *              - Resource-managed devfreq_unregister_opp_notifier()
+ * devm_devfreq_unregister_opp_notifier() - Resource-managed
+ *                                          devfreq_unregister_opp_notifier()
  * @dev:        The devfreq user device. (parent of devfreq)
  * @devfreq:    The devfreq object.
  */
@@ -1567,8 +1595,8 @@ EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
  * @list:       DEVFREQ_TRANSITION_NOTIFIER.
  */
 int devfreq_register_notifier(struct devfreq *devfreq,
-                                struct notifier_block *nb,
-                                unsigned int list)
+                              struct notifier_block *nb,
+                              unsigned int list)
 {
         int ret = 0;
 
@@ -1674,9 +1702,9 @@ EXPORT_SYMBOL(devm_devfreq_register_notifier);
  * @list:       DEVFREQ_TRANSITION_NOTIFIER.
  */
 void devm_devfreq_unregister_notifier(struct device *dev,
-                                struct devfreq *devfreq,
-                                struct notifier_block *nb,
-                                unsigned int list)
+                                      struct devfreq *devfreq,
+                                      struct notifier_block *nb,
+                                      unsigned int list)
 {
         WARN_ON(devres_release(dev, devm_devfreq_notifier_release,
                                devm_devfreq_dev_match, devfreq));