Re: [PATCH v4] platform/x86: asus-wmi: fix camera key LED on Zenbook S14

[José Guilherme de Castro Rodrigues]

Hi, Zane.

Thanks for the updated patch!
I've applied the patch locally and it works just fine on my Zenbook S 14

On Mon, Oct 19, 2026 at 07:35:18PM +1300, Zane Hunt via B4 Relay wrote:
> From: Zane Hunt <git@xxxxxxxxxxxx>
> 
> When CAMERA_LED is missing but CAMERA_LED_NEG is there, register
> asus::camera as a read-only LED backed by CAMERA_LED_NEG, and read it
> after every camera key event, sending a brightness_hw_changed event.
> Registering the LED reads it as well, which fixes the LED being dark after
> a cold boot with the camera disabled.

With this patch applied, a write to /sys/class/leds/asus::camera/brightness
returns no error, even though the led is "read-only". I'm wondering
whether we should care about this?

> +
> +/* The firmware owns this LED; a write just resyncs it with the camera state. */
> +static int camera_neg_led_set(struct led_classdev *led_cdev,
> +			      enum led_brightness brightness)
> +{
> +	struct asus_wmi *asus = container_of(led_cdev, struct asus_wmi, camera_led);
> +
> +	if (!(led_cdev->flags & LED_UNREGISTERING))
> +		camera_neg_led_sync(asus);
> +	return 0;
> +}
> +

Is this function necessary? We can't perform what the caller has asked
us to perform, since there is no way to set the LED. If this "resync"
functionality affects the behavior, please ignore this comment.

Apart from the comments, I'm fine with the patch as it is. I just
wondered these two things out loud.