[PATCH v3 1/2] platform/x86: asus-wmi: adjust screenpad power/brightness handling

Denis Benato
2026-03-02T17:44:46Z

Fix illogical screen off control by hardcoding 0 and 1 depending on the
requested brightness and also do not rely on the last screenpad
power state to issue screen brightness commands.

Fixes: 2c97d3e55b70 ("platform/x86: asus-wmi: add support for ASUS screenpad")
Signed-off-by: Denis Benato <denis.benato@linux.dev>
Signed-off-by: Luke Jones <luke@ljones.dev>
---
drivers/platform/x86/asus-wmi.c | 34 +++++++++++++--------------------
1 file changed, 13 insertions(+), 21 deletions(-)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 7c0915e097ba..8925a0ee26af 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -4419,32 +4419,24 @@ static int read_screenpad_brightness(struct backlight_device *bd)

static int update_screenpad_bl_status(struct backlight_device *bd)
{
- struct asus_wmi *asus = bl_get_data(bd);
- int power, err = 0;
- u32 ctrl_param;
+ u32 ctrl_param = bd->props.brightness;
+ int err = 0;

- power = read_screenpad_backlight_power(asus);
- if (power < 0)
- return power;
+ if (ctrl_param >= 0 && bd->props.power) {
+ err = asus_wmi_set_devstate(ASUS_WMI_DEVID_SCREENPAD_POWER, 1, NULL);
+ if (err < 0)
+ return err;

- if (bd->props.power != power) {
- if (power != BACKLIGHT_POWER_ON) {
- /* Only brightness > 0 can power it back on */
- ctrl_param = asus->driver->screenpad_brightness - ASUS_SCREENPAD_BRIGHT_MIN;
- err = asus_wmi_set_devstate(ASUS_WMI_DEVID_SCREENPAD_LIGHT,
- ctrl_param, NULL);
- } else {
- err = asus_wmi_set_devstate(ASUS_WMI_DEVID_SCREENPAD_POWER, 0, NULL);
- }
- } else if (power == BACKLIGHT_POWER_ON) {
- /* Only set brightness if powered on or we get invalid/unsync state */
- ctrl_param = bd->props.brightness + ASUS_SCREENPAD_BRIGHT_MIN;
err = asus_wmi_set_devstate(ASUS_WMI_DEVID_SCREENPAD_LIGHT, ctrl_param, NULL);
+ if (err < 0)
+ return err;
}

- /* Ensure brightness is stored to turn back on with */
- if (err == 0)
- asus->driver->screenpad_brightness = bd->props.brightness + ASUS_SCREENPAD_BRIGHT_MIN;
+ if (!bd->props.power) {
+ err = asus_wmi_set_devstate(ASUS_WMI_DEVID_SCREENPAD_POWER, 0, NULL);
+ if (err < 0)
+ return err;
+ }

return err;
}
--
2.53.0