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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-02-12 01:58:33 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-02-13 13:25:55 +0300
commit7b35370b2ebc2608ba0f2e0ecb996fa7f38e9731 (patch)
tree3453b01a4d65061046d53d805948b87aa4b64bed /kernel/power
parent87ad7356799622b69478076cd99df7a5024992cb (diff)
downloadlinux-7b35370b2ebc2608ba0f2e0ecb996fa7f38e9731.tar.xz
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>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/qos.c56
1 files changed, 29 insertions, 27 deletions
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index a6be7faa1974..6a36809d6160 100644
--- 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;
}