1 files changed, 13 insertions, 5 deletions

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index bcff7fdf733a..26518c8218ea 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -78,7 +78,14 @@ static void power_supply_changed_work(struct work_struct *work)
         dev_dbg(psy->dev, "%s\n", __func__);
 
         spin_lock_irqsave(&psy->changed_lock, flags);
-        if (psy->changed) {
+        /*
+         * Check 'changed' here to avoid issues due to race between
+         * power_supply_changed() and this routine. In worst case
+         * power_supply_changed() can be called again just before we take above
+         * lock. During the first call of this routine we will mark 'changed' as
+         * false and it will stay false for the next call as well.
+         */
+        if (likely(psy->changed)) {
                 psy->changed = false;
                 spin_unlock_irqrestore(&psy->changed_lock, flags);
                 class_for_each_device(power_supply_class, NULL, psy,
@@ -89,12 +96,13 @@ static void power_supply_changed_work(struct work_struct *work)
                 kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
                 spin_lock_irqsave(&psy->changed_lock, flags);
         }
+
         /*
-         * Dependent power supplies (e.g. battery) may have changed state
-         * as a result of this event, so poll again and hold the
-         * wakeup_source until all events are processed.
+         * Hold the wakeup_source until all events are processed.
+         * power_supply_changed() might have called again and have set 'changed'
+         * to true.
          */
-        if (!psy->changed)
+        if (likely(!psy->changed))
                 pm_relax(psy->dev);
         spin_unlock_irqrestore(&psy->changed_lock, flags);
 }