power_supply: Prevent suspend until power supply events are processed
This patch, originally authored by Arve Hjonnevag and Todd Poynor,
prevents the system from entering suspend mode until the power supply
plug, unplug, or any other change of state event is fully processed. This
guarantees that the screen lights up and displays the battery charging
state. The implementation uses the power supply wakeup_source object.
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Arve Hjonnevag <arve@android.com>
Cc: Todd Poynor <toddpoynor@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 3b2d5df..00e6672 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -67,23 +67,42 @@
static void power_supply_changed_work(struct work_struct *work)
{
+ unsigned long flags;
struct power_supply *psy = container_of(work, struct power_supply,
changed_work);
dev_dbg(psy->dev, "%s\n", __func__);
- class_for_each_device(power_supply_class, NULL, psy,
- __power_supply_changed_work);
-
- power_supply_update_leds(psy);
-
- kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
+ spin_lock_irqsave(&psy->changed_lock, flags);
+ if (psy->changed) {
+ psy->changed = false;
+ spin_unlock_irqrestore(&psy->changed_lock, flags);
+ class_for_each_device(power_supply_class, NULL, psy,
+ __power_supply_changed_work);
+ power_supply_update_leds(psy);
+ 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.
+ */
+ if (!psy->changed)
+ pm_relax(psy->dev);
+ spin_unlock_irqrestore(&psy->changed_lock, flags);
}
void power_supply_changed(struct power_supply *psy)
{
+ unsigned long flags;
+
dev_dbg(psy->dev, "%s\n", __func__);
+ spin_lock_irqsave(&psy->changed_lock, flags);
+ psy->changed = true;
+ pm_stay_awake(psy->dev);
+ spin_unlock_irqrestore(&psy->changed_lock, flags);
schedule_work(&psy->changed_work);
}
EXPORT_SYMBOL_GPL(power_supply_changed);
@@ -500,6 +519,11 @@
goto check_supplies_failed;
}
+ spin_lock_init(&psy->changed_lock);
+ rc = device_init_wakeup(dev, true);
+ if (rc)
+ goto wakeup_init_failed;
+
rc = kobject_set_name(&dev->kobj, "%s", psy->name);
if (rc)
goto kobject_set_name_failed;
@@ -529,6 +553,7 @@
register_cooler_failed:
psy_unregister_thermal(psy);
register_thermal_failed:
+wakeup_init_failed:
device_del(dev);
kobject_set_name_failed:
device_add_failed:
@@ -546,6 +571,7 @@
power_supply_remove_triggers(psy);
psy_unregister_cooler(psy);
psy_unregister_thermal(psy);
+ device_init_wakeup(psy->dev, false);
device_unregister(psy->dev);
}
EXPORT_SYMBOL_GPL(power_supply_unregister);