diff options
Diffstat (limited to 'drivers/power/power_supply_core.c')
| -rw-r--r-- | drivers/power/power_supply_core.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c index bcff7fdf733..26518c8218e 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); } |