PM: QoS: Clean up pm_qos_update_target() and pm_qos_update_flags()

Clean up the pm_qos_update_target() function:
 * Update its kerneldoc comment.
 * Drop the redundant ret local variable from it.
 * Reorder definitions of local variables in it.
 * Update a comment in it.

Also update the kerneldoc comment of pm_qos_update_flags() (e.g.
notifiers are not called by it any more) and add one emtpy line
to its body (for more visual clarity).

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>

diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index a6be7faa1974342f3f4e2ad46559553773cdc590..6a36809d6160283cc024a2665f50ac07a48b39cd 100644 (file)
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -129,24 +129,30 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
 }
 
 /**
- * pm_qos_update_target - manages the constraints list and calls the notifiers
- *  if needed
- * @c: constraints data struct
- * @node: request to add to the list, to update or to remove
- * @action: action to take on the constraints list
- * @value: value of the request to add or update
+ * pm_qos_update_target - Update a list of PM QoS constraint requests.
+ * @c: List of PM QoS requests.
+ * @node: Target list entry.
+ * @action: Action to carry out (add, update or remove).
+ * @value: New request value for the target list entry.
  *
- * This function returns 1 if the aggregated constraint value has changed, 0
- *  otherwise.
+ * Update the given list of PM QoS constraint requests, @c, by carrying an
+ * @action involving the @node list entry and @value on it.
+ *
+ * The recognized values of @action are PM_QOS_ADD_REQ (store @value in @node
+ * and add it to the list), PM_QOS_UPDATE_REQ (remove @node from the list, store
+ * @value in it and add it to the list again), and PM_QOS_REMOVE_REQ (remove
+ * @node from the list, ignore @value).
+ *
+ * Return: 1 if the aggregate constraint value has changed, 0  otherwise.
  */
 int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
                         enum pm_qos_req_action action, int value)
 {
-       unsigned long flags;
        int prev_value, curr_value, new_value;
-       int ret;
+       unsigned long flags;
 
        spin_lock_irqsave(&pm_qos_lock, flags);
+
        prev_value = pm_qos_get_value(c);
        if (value == PM_QOS_DEFAULT_VALUE)
                new_value = c->default_value;
@@ -159,9 +165,8 @@ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
                break;
        case PM_QOS_UPDATE_REQ:
                /*
-                * to change the list, we atomically remove, reinit
-                * with new value and add, then see if the extremal
-                * changed
+                * To change the list, atomically remove, reinit with new value
+                * and add, then see if the aggregate has changed.
                 */
                plist_del(node, &c->list);
                /* fall through */
@@ -180,16 +185,14 @@ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
        spin_unlock_irqrestore(&pm_qos_lock, flags);
 
        trace_pm_qos_update_target(action, prev_value, curr_value);
-       if (prev_value != curr_value) {
-               ret = 1;
-               if (c->notifiers)
-                       blocking_notifier_call_chain(c->notifiers,
-                                                    (unsigned long)curr_value,
-                                                    NULL);
-       } else {
-               ret = 0;
-       }
-       return ret;
+
+       if (prev_value == curr_value)
+               return 0;
+
+       if (c->notifiers)
+               blocking_notifier_call_chain(c->notifiers, curr_value, NULL);
+
+       return 1;
 }
 
 /**
@@ -211,14 +214,12 @@ static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf,
 
 /**
  * pm_qos_update_flags - Update a set of PM QoS flags.
- * @pqf: Set of flags to update.
+ * @pqf: Set of PM QoS flags to update.
  * @req: Request to add to the set, to modify, or to remove from the set.
  * @action: Action to take on the set.
  * @val: Value of the request to add or modify.
  *
- * Update the given set of PM QoS flags and call notifiers if the aggregate
- * value has changed.  Returns 1 if the aggregate constraint value has changed,
- * 0 otherwise.
+ * Return: 1 if the aggregate constraint value has changed, 0 otherwise.
  */
 bool pm_qos_update_flags(struct pm_qos_flags *pqf,
                         struct pm_qos_flags_request *req,
@@ -254,6 +255,7 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf,
        spin_unlock_irqrestore(&pm_qos_lock, irqflags);
 
        trace_pm_qos_update_flags(action, prev_value, curr_value);
+
        return prev_value != curr_value;
 }