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

[Denis Benato <denis.benato@linux.dev>]

On 2/24/26 05:15, luke@ljones.dev wrote:
>> On 24 Feb 2026, at 07:15, Denis Benato <denis.benato@linux.dev> 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.
Actually... my bad. I confused "Closes" with "Fixes". Ilpo meant to reference the original commit.

Sorry for the noise. I will dig those two tags.
>> 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@ljones.dev/
> 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@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 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;
>>>> }
>>>>