Commit e09c706b authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Lee Jones
Browse files

leds: trigger: Load trigger modules on-demand if used as default trigger 



Even if a trigger is set as default trigger for a LED device,
the respective trigger module (if built as module) isn't automatically
loaded by the kernel if the LED device is registered. I think we can
do better. Try to load the module asynchronously by alias
ledtrig:<trigger name>. This requires that such an alias is added to
relevant triggers.

Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/79adb260-06ad-443a-a68e-abe4498c3298@gmail.com


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent c47d1454

drivers/leds/led-triggers.c

+9 −0
Original line number Diff line number Diff line
@@ -250,6 +250,7 @@ EXPORT_SYMBOL_GPL(led_trigger_remove); 
void led_trigger_set_default(struct led_classdev *led_cdev)

{

	struct led_trigger *trig;

	bool found = false;



	if (!led_cdev->default_trigger)

		return;
@@ -259,6 +260,7 @@ void led_trigger_set_default(struct led_classdev *led_cdev) 
	list_for_each_entry(trig, &trigger_list, next_trig) {

		if (!strcmp(led_cdev->default_trigger, trig->name) &&

		    trigger_relevant(led_cdev, trig)) {

			found = true;

			led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;

			led_trigger_set(led_cdev, trig);

			break;
@@ -266,6 +268,13 @@ void led_trigger_set_default(struct led_classdev *led_cdev) 
	}

	up_write(&led_cdev->trigger_lock);

	up_read(&triggers_list_lock);



	/*

	 * If default trigger wasn't found, maybe trigger module isn't loaded yet.

	 * Once loaded it will re-probe with all led_cdev's.

	 */

	if (!found)

		request_module_nowait("ledtrig:%s", led_cdev->default_trigger);

}

EXPORT_SYMBOL_GPL(led_trigger_set_default);