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. The following works for me, however there are open points
regarding the module name/alias.
- Is it ok to assume that module name starts with "ledtrig-",
or better add a "ledtrig:xxx" scheme for trigger module aliases?
This would require MODULE_ALIAS'es for the existing triggers.
- Is it ok to assume that trigger name doesn't include whitespaces?
Or better remove potential whitespaces when assembling the
module/alias name?
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
drivers/leds/led-triggers.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index bd59a14a4..ab79b2c71 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -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);
--
2.43.0
