[PATCH] platform/x86: asus-wmi: use brightness_set_blocking() for kbd led

[PATCH] platform/x86: asus-wmi: use brightness_set_blocking() for kbd led

[Anton Khirnov]

kbd_led_set() can sleep, and so may not be used as the brightness_set()
callback.

Fixes "BUG: scheduling while atomic" when using this led with a trigger.

Fixes: 9fe44fc98ce4 ("platform/x86: asus-wmi: Simplify the keyboard brightness updating process")
Signed-off-by: Anton Khirnov <anton@khirnov.net>
---
 drivers/platform/x86/asus-wmi.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index e72a2b5d158e..638ff56e50a3 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -1619,14 +1619,15 @@ static void do_kbd_led_set(struct led_classdev *led_cdev, int value)
 	kbd_led_update(asus);
 }
 
-static void kbd_led_set(struct led_classdev *led_cdev,
-			enum led_brightness value)
+static int kbd_led_set(struct led_classdev *led_cdev,
+		       enum led_brightness value)
 {
 	/* Prevent disabling keyboard backlight on module unregister */
 	if (led_cdev->flags & LED_UNREGISTERING)
-		return;
+		return 0;
 
 	do_kbd_led_set(led_cdev, value);
+	return 0;
 }
 
 static void kbd_led_set_by_kbd(struct asus_wmi *asus, enum led_brightness value)
@@ -1802,7 +1803,7 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
 		asus->kbd_led_wk = led_val;
 		asus->kbd_led.name = "asus::kbd_backlight";
 		asus->kbd_led.flags = LED_BRIGHT_HW_CHANGED;
-		asus->kbd_led.brightness_set = kbd_led_set;
+		asus->kbd_led.brightness_set_blocking = kbd_led_set;
 		asus->kbd_led.brightness_get = kbd_led_get;
 		asus->kbd_led.max_brightness = 3;
 
-- 
2.47.3

Re: [PATCH] platform/x86: asus-wmi: use brightness_set_blocking() for kbd led

[Andy Shevchenko]

On Sat, Nov 29, 2025 at 05:02:46AM +0100, Anton Khirnov wrote:
> kbd_led_set() can sleep, and so may not be used as the brightness_set()
> callback.

> Fixes "BUG: scheduling while atomic" when using this led with a trigger.

It might be a bit confusing with (misspelled) Fixes tag, also it would be
better to provide a few (usually ~3-5) lines of the actual traceback.

...

> -static void kbd_led_set(struct led_classdev *led_cdev,
> -			enum led_brightness value)
> +static int kbd_led_set(struct led_classdev *led_cdev,
> +		       enum led_brightness value)

Now it's exactly 80 characters if located on a single line.

-- 
With Best Regards,
Andy Shevchenko