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

[luke]

> On 24 Feb 2026, at 07:15, Denis Benato <denis.benato@xxxxxxxxx> wrote:
> 
> 
> On 2/23/26 15:38, Ilpo Järvinen wrote:
>> On Thu, 12 Feb 2026, Denis Benato wrote:
>> 
>>> 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.
>> Should this have a Fixes tag?
>> 
> Same for the other patch: I am not sure.

It probably should be a fixes tag. Though there is no reference bug report or
other relating to it - only my discovery that the previously written code was in 
fact not right.

I had written the initial version that is in the kernel based on some limited testing
feedback from a user who was not able to clearly articulate what the issues
were and was happy with the final result.

I was able to get my hands on a Zenbook Duo and fully test this, which is how
I discovered the issues.

> What I know for certain is that Luke had an asus DUO to test this patch with
> and most certainly it was because someone contacted him about these bugs.
> 
> I split up commits found int the previous version of this patch:
> https://lore.kernel.org/all/20250525204214.104030-1-luke@xxxxxxxxxx/

Thanks for doing this. I just have not had any time to do it myself, very low on
the priority list but I would wager getting this all fixed correctly will enable both
Older and newer models to function how they should.

> I changed nothing else beside removing a redundant variable assignment.
>>> Signed-off-by: Denis Benato <denis.benato@xxxxxxxxx>
>>> Signed-off-by: Luke Jones <luke@xxxxxxxxxx>
>>> ---
>>> 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 0775fadedd10..4130dae37e15 100644
>>> --- a/drivers/platform/x86/asus-wmi.c
>>> +++ b/drivers/platform/x86/asus-wmi.c
>>> @@ -4254,32 +4254,24 @@ 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;
>>> + int err = 0;
>>> + u32 ctrl_param = bd->props.brightness;
>> Please retain reverse xmas-tree order.
>> 
>>> 
>>> - 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;
>>> }
>>>