diff options
Diffstat (limited to 'drivers/leds/led-class.c')
| -rw-r--r-- | drivers/leds/led-class.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 7440c58b8e6f..65722deb8d28 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -40,17 +40,27 @@ static ssize_t brightness_store(struct device *dev, { struct led_classdev *led_cdev = dev_get_drvdata(dev); unsigned long state; - ssize_t ret = -EINVAL; + ssize_t ret; + + mutex_lock(&led_cdev->led_access); + + if (led_sysfs_is_disabled(led_cdev)) { + ret = -EBUSY; + goto unlock; + } ret = kstrtoul(buf, 10, &state); if (ret) - return ret; + goto unlock; if (state == LED_OFF) led_trigger_remove(led_cdev); __led_set_brightness(led_cdev, state); - return size; + ret = size; +unlock: + mutex_unlock(&led_cdev->led_access); + return ret; } static DEVICE_ATTR_RW(brightness); @@ -214,6 +224,7 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) #ifdef CONFIG_LEDS_TRIGGERS init_rwsem(&led_cdev->trigger_lock); #endif + mutex_init(&led_cdev->led_access); /* add to the list of leds */ down_write(&leds_list_lock); list_add_tail(&led_cdev->node, &leds_list); @@ -267,6 +278,8 @@ void led_classdev_unregister(struct led_classdev *led_cdev) down_write(&leds_list_lock); list_del(&led_cdev->node); up_write(&leds_list_lock); + + mutex_destroy(&led_cdev->led_access); } EXPORT_SYMBOL_GPL(led_classdev_unregister); |