On Fri, 18 Sep 2026, Jorge Núñez Granero wrote:

> Some ASUS laptops (e.g. the ExpertBook B3405CCA) have a mute LED on the
> F1 key next to the mic mute LED on F4. The mic mute LED is already
> driven through WMI device 0x00040017, but the speaker mute LED is not
> known to the driver, so it never lights up under Linux while the
> firmware does light it under Windows.
> 
> The DSDT of the B3405CCA exposes device 0x0004001C in the same LED
> group with the presence bit set, and calling DEVS(0x0004001C, 1/0)
> turns the F1 key LED on and off.
> 
> Register it as "platform::mute" with the "audio-mute" default trigger,
> mirroring the existing mic mute LED, so that the snd-ctl-led speaker
> mode drives it automatically. Only registered when the firmware
> reports the device as present, so nothing changes on other models.
> 
> Tested on an ASUS ExpertBook B3405CCA (BIOS 307): DSTS reports the
> device present and DEVS 1/0 toggles the LED.
> 
> Signed-off-by: Jorge Núñez Granero <eljorge199525@gmail.com>

Thanks for the patch, but I've already queued another patch to this effect 
into the review-ilpo-next branch (from where it will eventually 
propagate to the for-next branch).

--
 i.

> ---
>  drivers/platform/x86/asus-wmi.c            | 24 ++++++++++++++++++++++
>  include/linux/platform_data/x86/asus-wmi.h |  1 +
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index a650904..60bbd10 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -262,6 +262,7 @@ struct asus_wmi {
>  	struct led_classdev lightbar_led;
>  	int lightbar_led_wk;
>  	struct led_classdev micmute_led;
> +	struct led_classdev mute_led;
>  	struct led_classdev camera_led;
>  	struct workqueue_struct *led_workqueue;
>  	struct work_struct tpd_led_work;
> @@ -2054,6 +2055,16 @@ static int micmute_led_set(struct led_classdev *led_cdev,
>  	return err < 0 ? err : 0;
>  }
>  
> +static int mute_led_set(struct led_classdev *led_cdev,
> +			enum led_brightness brightness)
> +{
> +	int state = brightness != LED_OFF;
> +	int err;
> +
> +	err = asus_wmi_set_devstate(ASUS_WMI_DEVID_MUTE_LED, state, NULL);
> +	return err < 0 ? err : 0;
> +}
> +
>  static enum led_brightness camera_led_get(struct led_classdev *led_cdev)
>  {
>  	struct asus_wmi *asus;
> @@ -2084,6 +2095,7 @@ static void asus_wmi_led_exit(struct asus_wmi *asus)
>  	led_classdev_unregister(&asus->wlan_led);
>  	led_classdev_unregister(&asus->lightbar_led);
>  	led_classdev_unregister(&asus->micmute_led);
> +	led_classdev_unregister(&asus->mute_led);
>  	led_classdev_unregister(&asus->camera_led);
>  
>  	if (asus->led_workqueue)
> @@ -2181,6 +2193,18 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
>  			goto error;
>  	}
>  
> +	if (asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_MUTE_LED)) {
> +		asus->mute_led.name = "platform::mute";
> +		asus->mute_led.max_brightness = 1;
> +		asus->mute_led.brightness_set_blocking = mute_led_set;
> +		asus->mute_led.default_trigger = "audio-mute";
> +
> +		rv = led_classdev_register(&asus->platform_device->dev,
> +					   &asus->mute_led);
> +		if (rv)
> +			goto error;
> +	}
> +
>  	if (asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_CAMERA_LED)) {
>  		asus->camera_led.name = "asus::camera";
>  		asus->camera_led.max_brightness = 1;
> diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> index b5ed8c8..6cb2e58 100644
> --- a/include/linux/platform_data/x86/asus-wmi.h
> +++ b/include/linux/platform_data/x86/asus-wmi.h
> @@ -54,6 +54,7 @@
>  #define ASUS_WMI_DEVID_LED5		0x00020015
>  #define ASUS_WMI_DEVID_LED6		0x00020016
>  #define ASUS_WMI_DEVID_MICMUTE_LED		0x00040017
> +#define ASUS_WMI_DEVID_MUTE_LED		0x0004001C
>  
>  /* Disable Camera LED */
>  #define ASUS_WMI_DEVID_CAMERA_LED_NEG	0x00060078 /* 0 = on (unused) */
>