leds: delay led_set_brightness if stopping soft-blink

Delay execution of led_set_brightness() if need to stop soft-blink
timer.

This allows led_set_brightness to be called in hard-irq context even if
soft-blink was activated on that LED.

Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index c599095bc005..48cce18e9d6d 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -124,6 +124,16 @@ static void led_timer_function(unsigned long data)
         mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
 }
 
+static void set_brightness_delayed(struct work_struct *ws)
+{
+        struct led_classdev *led_cdev =
+                container_of(ws, struct led_classdev, set_brightness_work);
+
+        led_stop_software_blink(led_cdev);
+
+        __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
+}
+
 /**
  * led_classdev_suspend - suspend an led_classdev.
  * @led_cdev: the led_classdev to suspend.
@@ -191,6 +201,8 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
 
         led_update_brightness(led_cdev);
 
+        INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
+
         init_timer(&led_cdev->blink_timer);
         led_cdev->blink_timer.function = led_timer_function;
         led_cdev->blink_timer.data = (unsigned long)led_cdev;
@@ -221,7 +233,10 @@ void led_classdev_unregister(struct led_classdev *led_cdev)
         up_write(&led_cdev->trigger_lock);
 #endif
 
+        cancel_work_sync(&led_cdev->set_brightness_work);
+
         /* Stop blinking */
+        led_stop_software_blink(led_cdev);
         led_set_brightness(led_cdev, LED_OFF);
 
         device_unregister(led_cdev->dev);