diff options
| -rw-r--r-- | drivers/leds/led-core.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c index f6c46d2e5276..e3d8ddcff567 100644 --- a/drivers/leds/led-core.c +++ b/drivers/leds/led-core.c @@ -159,8 +159,19 @@ static void set_brightness_delayed(struct work_struct *ws) * before this work item runs once. To make sure this works properly * handle LED_SET_BRIGHTNESS_OFF first. */ - if (test_and_clear_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags)) + if (test_and_clear_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags)) { set_brightness_delayed_set_brightness(led_cdev, LED_OFF); + /* + * The consecutives led_set_brightness(LED_OFF), + * led_set_brightness(LED_FULL) could have been executed out of + * order (LED_FULL first), if the work_flags has been set + * between LED_SET_BRIGHTNESS_OFF and LED_SET_BRIGHTNESS of this + * work. To avoid ending with the LED turned off, turn the LED + * on again. + */ + if (led_cdev->delayed_set_value != LED_OFF) + set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags); + } if (test_and_clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags)) set_brightness_delayed_set_brightness(led_cdev, led_cdev->delayed_set_value); @@ -331,10 +342,13 @@ void led_set_brightness_nopm(struct led_classdev *led_cdev, unsigned int value) * change is done immediately afterwards (before the work runs), * it uses a separate work_flag. */ - if (value) { - led_cdev->delayed_set_value = value; + led_cdev->delayed_set_value = value; + /* Ensure delayed_set_value is seen before work_flags modification */ + smp_mb__before_atomic(); + + if (value) set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags); - } else { + else { clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags); clear_bit(LED_SET_BLINK, &led_cdev->work_flags); set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags); |