jz4740-battery: Protect against concurrent battery readings
We can not handle more then one ADC request at a time to the battery.
The patch adds a mutex around the ADC read code to ensure this.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: stable@kernel.org
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
diff --git a/drivers/power/jz4740-battery.c b/drivers/power/jz4740-battery.c
index a8108a7..2bbe04a 100644
--- a/drivers/power/jz4740-battery.c
+++ b/drivers/power/jz4740-battery.c
@@ -47,6 +47,8 @@
struct power_supply battery;
struct delayed_work work;
+
+ struct mutex lock;
};
static inline struct jz_battery *psy_to_jz_battery(struct power_supply *psy)
@@ -68,6 +70,8 @@
unsigned long val;
long voltage;
+ mutex_lock(&battery->lock);
+
INIT_COMPLETION(battery->read_completion);
enable_irq(battery->irq);
@@ -91,6 +95,8 @@
battery->cell->disable(battery->pdev);
disable_irq(battery->irq);
+ mutex_unlock(&battery->lock);
+
return voltage;
}
@@ -291,6 +297,7 @@
jz_battery->pdev = pdev;
init_completion(&jz_battery->read_completion);
+ mutex_init(&jz_battery->lock);
INIT_DELAYED_WORK(&jz_battery->work, jz_battery_work);