From 8ec98fe0b4ffdedce4c1caa9fb3d550f52ad1c6b Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Thu, 11 Nov 2010 19:00:52 +0100 Subject: 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 Cc: stable@kernel.org Signed-off-by: Anton Vorontsov --- drivers/power/jz4740-battery.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/power') diff --git a/drivers/power/jz4740-battery.c b/drivers/power/jz4740-battery.c index a8108a73593e..2bbe04ae13a7 100644 --- 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(struct jz_battery *battery) 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(struct jz_battery *battery) 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(struct platform_device *pdev) jz_battery->pdev = pdev; init_completion(&jz_battery->read_completion); + mutex_init(&jz_battery->lock); INIT_DELAYED_WORK(&jz_battery->work, jz_battery_work); -- cgit v1.2.3