5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
[ Upstream commit ab477b766edd3bfb6321a6e3df4c790612613fae ]
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: 0db37915d912 ("leds: avoid races with workqueue")
Fixes: 8c0f693c6eff ("leds: avoid flush_work in atomic context")
Cc: stable@xxxxxxxxxxxxxxx
Tested-by: Dustin L. Howett <dustin@xxxxxxxxxx>
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240613-led-trigger-flush-v2-1-f4f970799d77@xxxxxxxxxxxxxx
Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/leds/led-triggers.c | 6 ++++++
drivers/leds/trigger/ledtrig-timer.c | 5 -----
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index fe7fb2e7149c5..3d3673c197e38 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -200,6 +200,12 @@ 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);
diff --git a/drivers/leds/trigger/ledtrig-timer.c b/drivers/leds/trigger/ledtrig-timer.c
index b4688d1d9d2b2..1d213c999d40a 100644
--- a/drivers/leds/trigger/ledtrig-timer.c
+++ b/drivers/leds/trigger/ledtrig-timer.c
@@ -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);
--
2.43.0
