power_supply: Hold a wake_lock while power supply change notifications are pending

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When connecting usb or the charger the device would often go back to sleep
before the charge led and screen turned on.

Change-Id: I01def6d86ddece0d4e31d2a91d176ed0975b6b9d
Signed-off-by: Arve Hjønnevåg <arve@android.com>

2 files changed, 30 insertions, 4 deletions

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 329b46b2327..03810ce5633 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -41,23 +41,40 @@ static int __power_supply_changed_work(struct device *dev, void *data)
 
 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);
+	spin_lock_irqsave(&psy->changed_lock, flags);
+	if (psy->changed) {
+		psy->changed = false;
+		spin_unlock_irqrestore(&psy->changed_lock, flags);
 
-	power_supply_update_leds(psy);
+		class_for_each_device(power_supply_class, NULL, psy,
+				      __power_supply_changed_work);
 
-	kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
+		power_supply_update_leds(psy);
+
+		kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
+		spin_lock_irqsave(&psy->changed_lock, flags);
+	}
+	if (!psy->changed)
+		wake_unlock(&psy->work_wake_lock);
+	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;
+	wake_lock(&psy->work_wake_lock);
+	spin_unlock_irqrestore(&psy->changed_lock, flags);
 	schedule_work(&psy->changed_work);
 }
 EXPORT_SYMBOL_GPL(power_supply_changed);
@@ -181,6 +198,9 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
 	if (rc)
 		goto device_add_failed;
 
+	spin_lock_init(&psy->changed_lock);
+	wake_lock_init(&psy->work_wake_lock, WAKE_LOCK_SUSPEND, "power-supply");
+
 	rc = power_supply_create_triggers(psy);
 	if (rc)
 		goto create_triggers_failed;
@@ -190,6 +210,7 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
 	goto success;
 
 create_triggers_failed:
+	wake_lock_destroy(&psy->work_wake_lock);
 	device_del(dev);
 kobject_set_name_failed:
 device_add_failed:
@@ -203,6 +224,7 @@ void power_supply_unregister(struct power_supply *psy)
 {
 	cancel_work_sync(&psy->changed_work);
 	power_supply_remove_triggers(psy);
+	wake_lock_destroy(&psy->work_wake_lock);
 	device_unregister(psy->dev);
 }
 EXPORT_SYMBOL_GPL(power_supply_unregister);
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 204c18dfdc9..2287c321413 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -14,6 +14,7 @@
 #define __LINUX_POWER_SUPPLY_H__
 
 #include <linux/device.h>
+#include <linux/wakelock.h>
 #include <linux/workqueue.h>
 #include <linux/leds.h>
 
@@ -163,6 +164,9 @@ struct power_supply {
 	/* private */
 	struct device *dev;
 	struct work_struct changed_work;
+	spinlock_t changed_lock;
+	bool changed;
+	struct wake_lock work_wake_lock;
 
 #ifdef CONFIG_LEDS_TRIGGERS
 	struct led_trigger *charging_full_trig;