PM / OPP: Allocate dev_opp from _add_device_opp()

There is no need to complicate _opp_add_dynamic() with allocation of
dev_opp as well. Allocate it from _add_device_opp() instead.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 7895fdd64192097e49803d2b3505ed3db1c74be3..28d70c9f86eda19068d3f421bd44b47c4756fcbd 100644 (file)
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -408,11 +408,11 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 
 /**
- * _add_device_opp() - Allocate a new device OPP table
+ * _add_device_opp() - Find device OPP table or allocate a new one
  * @dev:       device for which we do this operation
  *
- * New device node which uses OPPs - used when multiple devices with OPP tables
- * are maintained.
+ * It tries to find an existing table first, if it couldn't find one, it
+ * allocates a new OPP table and returns that.
  *
  * Return: valid device_opp pointer if success, else NULL.
  */
@@ -420,6 +420,11 @@ static struct device_opp *_add_device_opp(struct device *dev)
 {
        struct device_opp *dev_opp;
 
+       /* Check for existing list for 'dev' first */
+       dev_opp = _find_device_opp(dev);
+       if (!IS_ERR(dev_opp))
+               return dev_opp;
+
        /*
         * Allocate a new device OPP table. In the infrequent case where a new
         * device is needed to be added, we pay this penalty.
@@ -575,7 +580,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
 static int _opp_add_dynamic(struct device *dev, unsigned long freq,
                            long u_volt, bool dynamic)
 {
-       struct device_opp *dev_opp = NULL;
+       struct device_opp *dev_opp;
        struct dev_pm_opp *opp, *new_opp;
        struct list_head *head;
        int ret;
@@ -592,19 +597,11 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
        new_opp->rate = freq;
        new_opp->u_volt = u_volt;
        new_opp->available = true;
-       new_opp->dynamic = dynamic;
-
-       /* Check for existing list for 'dev' */
-       dev_opp = _find_device_opp(dev);
-       if (IS_ERR(dev_opp)) {
-               dev_opp = _add_device_opp(dev);
-               if (!dev_opp) {
-                       ret = -ENOMEM;
-                       goto free_opp;
-               }
 
-               head = &dev_opp->opp_list;
-               goto list_add;
+       dev_opp = _add_device_opp(dev);
+       if (!dev_opp) {
+               ret = -ENOMEM;
+               goto free_opp;
        }
 
        /*
@@ -612,15 +609,22 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
         * and discard if already present
         */
        head = &dev_opp->opp_list;
+
+       /*
+        * Need to use &dev_opp->opp_list in the condition part of the 'for'
+        * loop, don't replace it with head otherwise it will become an infinite
+        * loop.
+        */
        list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
-               if (new_opp->rate <= opp->rate)
-                       break;
-               else
+               if (new_opp->rate > opp->rate) {
                        head = &opp->node;
-       }
+                       continue;
+               }
+
+               if (new_opp->rate < opp->rate)
+                       break;
 
-       /* Duplicate OPPs ? */
-       if (new_opp->rate == opp->rate) {
+               /* Duplicate OPPs */
                ret = opp->available && new_opp->u_volt == opp->u_volt ?
                        0 : -EEXIST;
 
@@ -630,7 +634,7 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
                goto free_opp;
        }
 
-list_add:
+       new_opp->dynamic = dynamic;
        new_opp->dev_opp = dev_opp;
        list_add_rcu(&new_opp->node, head);
        mutex_unlock(&dev_opp_list_lock);