[PATCH v9 08/11] HID: asus: listen to the asus-wmi brightness device instead of creating one

Antheas Kapenekakis
2025-11-20T09:46:37Z

Some ROG laptops expose multiple interfaces for controlling the
keyboard/RGB brightness. This creates a name conflict under
asus::kbd_brightness, where the second device ends up being
named asus::kbd_brightness_1 and they are both broken.

Therefore, register a listener to the asus-wmi brightness device
instead of creating a new one.

Reviewed-by: Luke D. Jones <luke@ljones.dev>
Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
---
drivers/hid/hid-asus.c | 64 +++++++-----------------------------------
1 file changed, 10 insertions(+), 54 deletions(-)

diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index 6193c9483bec..6a355c174f29 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -102,7 +102,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
#define TRKID_SGN ((TRKID_MAX + 1) >> 1)

struct asus_kbd_leds {
- struct led_classdev cdev;
+ struct asus_hid_listener listener;
struct hid_device *hdev;
struct work_struct work;
unsigned int brightness;
@@ -494,11 +494,11 @@ static void asus_schedule_work(struct asus_kbd_leds *led)
spin_unlock_irqrestore(&led->lock, flags);
}

-static void asus_kbd_backlight_set(struct led_classdev *led_cdev,
- enum led_brightness brightness)
+static void asus_kbd_backlight_set(struct asus_hid_listener *listener,
+ int brightness)
{
- struct asus_kbd_leds *led = container_of(led_cdev, struct asus_kbd_leds,
- cdev);
+ struct asus_kbd_leds *led = container_of(listener, struct asus_kbd_leds,
+ listener);
unsigned long flags;

spin_lock_irqsave(&led->lock, flags);
@@ -508,20 +508,6 @@ static void asus_kbd_backlight_set(struct led_classdev *led_cdev,
asus_schedule_work(led);
}

-static enum led_brightness asus_kbd_backlight_get(struct led_classdev *led_cdev)
-{
- struct asus_kbd_leds *led = container_of(led_cdev, struct asus_kbd_leds,
- cdev);
- enum led_brightness brightness;
- unsigned long flags;
-
- spin_lock_irqsave(&led->lock, flags);
- brightness = led->brightness;
- spin_unlock_irqrestore(&led->lock, flags);
-
- return brightness;
-}
-
static void asus_kbd_backlight_work(struct work_struct *work)
{
struct asus_kbd_leds *led = container_of(work, struct asus_kbd_leds, work);
@@ -538,34 +524,6 @@ static void asus_kbd_backlight_work(struct work_struct *work)
hid_err(led->hdev, "Asus failed to set keyboard backlight: %d\n", ret);
}

-/* WMI-based keyboard backlight LED control (via asus-wmi driver) takes
- * precedence. We only activate HID-based backlight control when the
- * WMI control is not available.
- */
-static bool asus_kbd_wmi_led_control_present(struct hid_device *hdev)
-{
- struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
- u32 value;
- int ret;
-
- if (!IS_ENABLED(CONFIG_ASUS_WMI))
- return false;
-
- if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD &&
- dmi_check_system(asus_use_hid_led_dmi_ids)) {
- hid_info(hdev, "using HID for asus::kbd_backlight\n");
- return false;
- }
-
- ret = asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS,
- ASUS_WMI_DEVID_KBD_BACKLIGHT, 0, &value);
- hid_dbg(hdev, "WMI backlight check: rc %d value %x", ret, value);
- if (ret)
- return false;
-
- return !!(value & ASUS_WMI_DSTS_PRESENCE_BIT);
-}
-
/*
* We don't care about any other part of the string except the version section.
* Example strings: FGA80100.RC72LA.312_T01, FGA80100.RC71LS.318_T01
@@ -710,14 +668,11 @@ static int asus_kbd_register_leds(struct hid_device *hdev)
drvdata->kbd_backlight->removed = false;
drvdata->kbd_backlight->brightness = 0;
drvdata->kbd_backlight->hdev = hdev;
- drvdata->kbd_backlight->cdev.name = "asus::kbd_backlight";
- drvdata->kbd_backlight->cdev.max_brightness = 3;
- drvdata->kbd_backlight->cdev.brightness_set = asus_kbd_backlight_set;
- drvdata->kbd_backlight->cdev.brightness_get = asus_kbd_backlight_get;
+ drvdata->kbd_backlight->listener.brightness_set = asus_kbd_backlight_set;
INIT_WORK(&drvdata->kbd_backlight->work, asus_kbd_backlight_work);
spin_lock_init(&drvdata->kbd_backlight->lock);

- ret = devm_led_classdev_register(&hdev->dev, &drvdata->kbd_backlight->cdev);
+ ret = asus_hid_register_listener(&drvdata->kbd_backlight->listener);
if (ret < 0) {
/* No need to have this still around */
devm_kfree(&hdev->dev, drvdata->kbd_backlight);
@@ -1106,7 +1061,7 @@ static int __maybe_unused asus_resume(struct hid_device *hdev) {

if (drvdata->kbd_backlight) {
const u8 buf[] = { FEATURE_KBD_REPORT_ID, 0xba, 0xc5, 0xc4,
- drvdata->kbd_backlight->cdev.brightness };
+ drvdata->kbd_backlight->brightness };
ret = asus_kbd_set_report(hdev, buf, sizeof(buf));
if (ret < 0) {
hid_err(hdev, "Asus failed to set keyboard backlight: %d\n", ret);
@@ -1232,7 +1187,6 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
}

if (is_vendor && (drvdata->quirks & QUIRK_USE_KBD_BACKLIGHT) &&
- !asus_kbd_wmi_led_control_present(hdev) &&
asus_kbd_register_leds(hdev))
hid_warn(hdev, "Failed to initialize backlight.\n");

@@ -1279,6 +1233,8 @@ static void asus_remove(struct hid_device *hdev)
unsigned long flags;

if (drvdata->kbd_backlight) {
+ asus_hid_unregister_listener(&drvdata->kbd_backlight->listener);
+
spin_lock_irqsave(&drvdata->kbd_backlight->lock, flags);
drvdata->kbd_backlight->removed = true;
spin_unlock_irqrestore(&drvdata->kbd_backlight->lock, flags);
--
2.52.0