Re: [PATCH v3 7/7] HID: asus: Re-send the Zenbook Duo keyboard handshake after probe

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

On 10/19/26 15:36, Rebecca Mara Müller wrote:
> On Mon, Oct 19, 2026 at 01:03:34PM +0200, Denis Benato wrote:
>> Very good to see it sleeps just fine. So yeah a command is missing...
> Thank you for the roadmap, I went through it on the UX8407AA with
> BIOS UX8407AA.308. I have since updated to 310, the latest one; its
> ACPI tables only differ from 308 in relocated memory regions, so the
> findings below should hold for both:

Most findings will hold for multiple models across different years
as asus reuses a lot of code for the same lineup. Thankfully!

> - asus-nb-wmi only exposes the basics here (kbd_backlight 0-3,
>   throttle_thermal_policy, charge_mode, screenpad); no TUF/ROG lighting
>   or power-state attributes.

Fair enough.

> - In the decompiled DSDT, WMNB answers 75 device IDs. None of the
>   TUF LED power IDs is among them, so it is not a firmware that claims
>   "unsupported" and accepts the write anyway. The kbd backlight ID
>   0x00050021 goes to the EC (SLKB), which does not reach the detachable
>   keyboard, a separate USB/BT device.

Does this laptop have other lights? I wonder what that is changing...

> - The LPS0 _DSM in PEPD only notifies the EC (MS entry/exit 0x9a/0x9b,
>   display off/on 0xb7/0xb8, entry/exit 0xae/0xaf). With
>   pm_debug_messages on, Linux calls all of them on s2idle (screen off,
>   lps0 ms entry, lps0 entry, and the exits), so nothing is skipped on
>   our side.

I have a cursed TUF that does the same and looks correct and yet it
doesn't sleep in linux... Someday I will understand what's going on
with that. Thankfully it's not the case here as the sleep residency
is high for you.

> - With dynamic debug on usbcore, the keyboard does go to USB suspend
>   ("usb 3-6: usb suspend, wakeup 1", and "wakeup 0" with wakeup
>   disabled), and the backlight stays on in both cases.

Wow... okay... so it was actually designed this way. 

> - The backlight only goes off when the keyboard loses the connection:
>   lifting it off the dock during s2idle turns it off immediately.

Probably because the idea is that "keyboard lit" = "ready to go"/"press a key to resume".

> So the keyboard simply keeps its backlight while it is connected, and
> I guess Windows either cuts the port power in Modern Standby or MyASUS
> turns the light off. I have no Windows on this machine at the moment
> to check which.

Could be that they simply leave it on as said above.

Doesn't look like something to be investigated further, perhaps try to see
if there is some unknown devid in wmi that does something cool.

> Following your advice I did it in userspace: a systemd-sleep hook that
> saves asus::kbd_backlight and writes 0 on "pre", and restores it on
> "post". With v3 loaded the light now goes off just before the screen
> and comes back on resume. If it is useful to anyone else I can post it.

in the OGC discord (ex asus-linux discord, you find it on our website) people
are planning a GUI redesign, perhaps if you have spare time you can add an option
to asusd to shutdown leds when entering sleep to have a GUI on a widely used tool
but I think this is time consuming enough that is probably not worth unless you find
it funny to do.

> Thanks,
> Rebecca