[146/272] jz4740-battery: Protect against concurrent battery readings

Greg KH
2011-02-16T00:22:20Z

From: Lars-Peter Clausen <lars@metafoo.de>

commit 8ec98fe0b4ffdedce4c1caa9fb3d550f52ad1c6b upstream.

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>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/power/jz4740-battery.c | 7 +++++++
1 file changed, 7 insertions(+)

--- a/drivers/power/jz4740-battery.c
+++ b/drivers/power/jz4740-battery.c
@@ -47,6 +47,8 @@ struct jz_battery {

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 @@ static long jz_battery_read_voltage(stru
unsigned long val;
long voltage;

+ mutex_lock(&battery->lock);
+
INIT_COMPLETION(battery->read_completion);

enable_irq(battery->irq);
@@ -91,6 +95,8 @@ static long jz_battery_read_voltage(stru
battery->cell->disable(battery->pdev);
disable_irq(battery->irq);

+ mutex_unlock(&battery->lock);
+
return voltage;
}

@@ -291,6 +297,7 @@ static int __devinit jz_battery_probe(st
jz_battery->pdev = pdev;

init_completion(&jz_battery->read_completion);
+ mutex_init(&jz_battery->lock);

INIT_DELAYED_WORK(&jz_battery->work, jz_battery_work);