[PATCH v6 0/7] HID: asus: Fix ASUS ROG Laptop's Keyboard backlight handling

Antheas Kapenekakis
2025-10-13T20:23:40Z

This is a two part series which does the following:
- Clean-up init sequence
- Unify backlight handling to happen under asus-wmi so that all Aura
devices have synced brightness controls and the backlight button works
properly when it is on a USB laptop keyboard instead of one w/ WMI.

For more context, see cover letter of V1. Since V5, I removed some patches
to make this easier to merge.

All comments with these patches had been addressed since V4.

---
V5: https://lore.kernel.org/all/20250325184601.10990-1-lkml@antheas.dev/
V4: https://lore.kernel.org/lkml/20250324210151.6042-1-lkml@antheas.dev/
V3: https://lore.kernel.org/lkml/20250322102804.418000-1-lkml@antheas.dev/
V2: https://lore.kernel.org/all/20250320220924.5023-1-lkml@antheas.dev/
V1: https://lore.kernel.org/all/20250319191320.10092-1-lkml@antheas.dev/

Changes since V5:
- It's been a long time
- Remove addition of RGB as that had some comments I need to work on
- Remove folio patch (already merged)
- Remove legacy fix patch 11 from V4. There is a small chance that
without this patch, some old NKEY keyboards might not respond to
RGB commands according to Luke, but the kernel driver does not do
RGB currently. The 0x5d init is done by Armoury crate software in
Windows. If an issue is found, we can re-add it or just remove patches
1/2 before merging. However, init could use the cleanup.

Changes since V4:
- Fix KConfig (reported by kernel robot)
- Fix Ilpo's nits, if I missed anything lmk

Changes since V3:
- Add initializer for 0x5d for old NKEY keyboards until it is verified
that it is not needed for their media keys to function.
- Cover init in asus-wmi with spinlock as per Hans
- If asus-wmi registers WMI handler with brightness, init the brightness
in USB Asus keyboards, per Hans.
- Change hid handler name to asus-UNIQ:rgb:peripheral to match led class
- Fix oops when unregistering asus-wmi by moving unregister outside of
the spin lock (but after the asus reference is set to null)

Changes since V2:
- Check lazy init succeds in asus-wmi before setting register variable
- make explicit check in asus_hid_register_listener for listener existing
to avoid re-init
- rename asus_brt to asus_hid in most places and harmonize everything
- switch to a spinlock instead of a mutex to avoid kernel ooops
- fixup hid device quirks to avoid multiple RGB devices while still exposing
all input vendor devices. This includes moving rgb init to probe
instead of the input_configured callbacks.
- Remove fan key (during retest it appears to be 0xae that is already
supported by hid-asus)
- Never unregister asus::kbd_backlight while asus-wmi is active, as that
- removes fds from userspace and breaks backlight functionality. All
- current mainline drivers do not support backlight hotplugging, so most
userspace software (e.g., KDE, UPower) is built with that assumption.
For the Ally, since it disconnects its controller during sleep, this
caused the backlight slider to not work in KDE.

Changes since V1:
- Add basic RGB support on hid-asus, (Z13/Ally) tested in KDE/Z13
- Fix ifdef else having an invalid signature (reported by kernel robot)
- Restore input arguments to init and keyboard function so they can
be re-used for RGB controls.
- Remove Z13 delay (it did not work to fix the touchpad) and replace it
with a HID_GROUP_GENERIC quirk to allow hid-multitouch to load. Squash
keyboard rename into it.
- Unregister brightness listener before removing work queue to avoid
a race condition causing corruption
- Remove spurious mutex unlock in asus_brt_event
- Place mutex lock in kbd_led_set after LED_UNREGISTERING check to avoid
relocking the mutex and causing a deadlock when unregistering leds
- Add extra check during unregistering to avoid calling unregister when
no led device is registered.
- Temporarily HID_QUIRK_INPUT_PER_APP from the ROG endpoint as it causes
the driver to create 4 RGB handlers per device. I also suspect some
extra events sneak through (KDE had the @@@@@@).

Antheas Kapenekakis (7):
HID: asus: refactor init sequence per spec
HID: asus: prevent binding to all HID devices on ROG
platform/x86: asus-wmi: Add support for multiple kbd RGB handlers
HID: asus: listen to the asus-wmi brightness device instead of
creating one
platform/x86: asus-wmi: remove unused keyboard backlight quirk
platform/x86: asus-wmi: add keyboard brightness event handler
HID: asus: add support for the asus-wmi brightness handler

drivers/hid/hid-asus.c | 235 +++++++++++----------
drivers/platform/x86/asus-wmi.c | 157 ++++++++++++--
include/linux/platform_data/x86/asus-wmi.h | 69 +++---
3 files changed, 291 insertions(+), 170 deletions(-)

base-commit: 3a8660878839faadb4f1a6dd72c3179c1df56787
--
2.51.0