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

[Rebecca Mara Müller]

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:

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

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.

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.

Thanks,
Rebecca