Commit ab477b76 authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Lee Jones
Browse files

leds: triggers: Flush pending brightness before activating trigger 



The race fixed in timer_trig_activate() between a blocking
set_brightness() call and trigger->activate() can affect any trigger.
So move the call to flush_work() into led_trigger_set() where it can
avoid the race for all triggers.

Fixes: 0db37915 ("leds: avoid races with workqueue")
Fixes: 8c0f693c ("leds: avoid flush_work in atomic context")
Cc: stable@vger.kernel.org
Tested-by: default avatarDustin L. Howett <dustin@howett.net>
Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20240613-led-trigger-flush-v2-1-f4f970799d77@weissschuh.net


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 25458b2a

drivers/leds/led-triggers.c

+6 −0
Original line number Diff line number Diff line
@@ -201,6 +201,12 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig) 
		 */

		synchronize_rcu();



		/*

		 * If "set brightness to 0" is pending in workqueue,

		 * we don't want that to be reordered after ->activate()

		 */

		flush_work(&led_cdev->set_brightness_work);



		ret = 0;

		if (trig->activate)

			ret = trig->activate(led_cdev);

drivers/leds/trigger/ledtrig-timer.c

+0 −5
Original line number Diff line number Diff line
@@ -110,11 +110,6 @@ static int timer_trig_activate(struct led_classdev *led_cdev) 
		led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;

	}



	/*

	 * If "set brightness to 0" is pending in workqueue, we don't

	 * want that to be reordered after blink_set()

	 */

	flush_work(&led_cdev->set_brightness_work);

	led_blink_set(led_cdev, &led_cdev->blink_delay_on,

		      &led_cdev->blink_delay_off);