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path: root/drivers/base/power/wakeup.c
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Diffstat (limited to 'drivers/base/power/wakeup.c')
-rw-r--r--drivers/base/power/wakeup.c85
1 files changed, 64 insertions, 21 deletions
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index caf995fb774..2a3e581b8dc 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -53,6 +53,23 @@ static void pm_wakeup_timer_fn(unsigned long data);
static LIST_HEAD(wakeup_sources);
/**
+ * wakeup_source_prepare - Prepare a new wakeup source for initialization.
+ * @ws: Wakeup source to prepare.
+ * @name: Pointer to the name of the new wakeup source.
+ *
+ * Callers must ensure that the @name string won't be freed when @ws is still in
+ * use.
+ */
+void wakeup_source_prepare(struct wakeup_source *ws, const char *name)
+{
+ if (ws) {
+ memset(ws, 0, sizeof(*ws));
+ ws->name = name;
+ }
+}
+EXPORT_SYMBOL_GPL(wakeup_source_prepare);
+
+/**
* wakeup_source_create - Create a struct wakeup_source object.
* @name: Name of the new wakeup source.
*/
@@ -60,37 +77,44 @@ struct wakeup_source *wakeup_source_create(const char *name)
{
struct wakeup_source *ws;
- ws = kzalloc(sizeof(*ws), GFP_KERNEL);
+ ws = kmalloc(sizeof(*ws), GFP_KERNEL);
if (!ws)
return NULL;
- spin_lock_init(&ws->lock);
- if (name)
- ws->name = kstrdup(name, GFP_KERNEL);
-
+ wakeup_source_prepare(ws, name ? kstrdup(name, GFP_KERNEL) : NULL);
return ws;
}
EXPORT_SYMBOL_GPL(wakeup_source_create);
/**
+ * wakeup_source_drop - Prepare a struct wakeup_source object for destruction.
+ * @ws: Wakeup source to prepare for destruction.
+ *
+ * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never
+ * be run in parallel with this function for the same wakeup source object.
+ */
+void wakeup_source_drop(struct wakeup_source *ws)
+{
+ if (!ws)
+ return;
+
+ del_timer_sync(&ws->timer);
+ __pm_relax(ws);
+}
+EXPORT_SYMBOL_GPL(wakeup_source_drop);
+
+/**
* wakeup_source_destroy - Destroy a struct wakeup_source object.
* @ws: Wakeup source to destroy.
+ *
+ * Use only for wakeup source objects created with wakeup_source_create().
*/
void wakeup_source_destroy(struct wakeup_source *ws)
{
if (!ws)
return;
- spin_lock_irq(&ws->lock);
- while (ws->active) {
- spin_unlock_irq(&ws->lock);
-
- schedule_timeout_interruptible(msecs_to_jiffies(TIMEOUT));
-
- spin_lock_irq(&ws->lock);
- }
- spin_unlock_irq(&ws->lock);
-
+ wakeup_source_drop(ws);
kfree(ws->name);
kfree(ws);
}
@@ -105,6 +129,7 @@ void wakeup_source_add(struct wakeup_source *ws)
if (WARN_ON(!ws))
return;
+ spin_lock_init(&ws->lock);
setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws);
ws->active = false;
@@ -152,8 +177,10 @@ EXPORT_SYMBOL_GPL(wakeup_source_register);
*/
void wakeup_source_unregister(struct wakeup_source *ws)
{
- wakeup_source_remove(ws);
- wakeup_source_destroy(ws);
+ if (ws) {
+ wakeup_source_remove(ws);
+ wakeup_source_destroy(ws);
+ }
}
EXPORT_SYMBOL_GPL(wakeup_source_unregister);
@@ -349,7 +376,6 @@ static void wakeup_source_activate(struct wakeup_source *ws)
{
ws->active = true;
ws->active_count++;
- ws->timer_expires = jiffies;
ws->last_time = ktime_get();
/* Increment the counter of events in progress. */
@@ -370,9 +396,14 @@ void __pm_stay_awake(struct wakeup_source *ws)
return;
spin_lock_irqsave(&ws->lock, flags);
+
ws->event_count++;
if (!ws->active)
wakeup_source_activate(ws);
+
+ del_timer(&ws->timer);
+ ws->timer_expires = 0;
+
spin_unlock_irqrestore(&ws->lock, flags);
}
EXPORT_SYMBOL_GPL(__pm_stay_awake);
@@ -438,6 +469,7 @@ static void wakeup_source_deactivate(struct wakeup_source *ws)
ws->max_time = duration;
del_timer(&ws->timer);
+ ws->timer_expires = 0;
/*
* Increment the counter of registered wakeup events and decrement the
@@ -492,11 +524,22 @@ EXPORT_SYMBOL_GPL(pm_relax);
* pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
* @data: Address of the wakeup source object associated with the event source.
*
- * Call __pm_relax() for the wakeup source whose address is stored in @data.
+ * Call wakeup_source_deactivate() for the wakeup source whose address is stored
+ * in @data if it is currently active and its timer has not been canceled and
+ * the expiration time of the timer is not in future.
*/
static void pm_wakeup_timer_fn(unsigned long data)
{
- __pm_relax((struct wakeup_source *)data);
+ struct wakeup_source *ws = (struct wakeup_source *)data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ws->lock, flags);
+
+ if (ws->active && ws->timer_expires
+ && time_after_eq(jiffies, ws->timer_expires))
+ wakeup_source_deactivate(ws);
+
+ spin_unlock_irqrestore(&ws->lock, flags);
}
/**
@@ -534,7 +577,7 @@ void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec)
if (!expires)
expires = 1;
- if (time_after(expires, ws->timer_expires)) {
+ if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
mod_timer(&ws->timer, expires);
ws->timer_expires = expires;
}