Source: linux
Version: 6.12.111-1
Severity: normal
Hardware: ASUSTeK COMPUTER INC. ROG Strix G512LV_G512LV/G512LV, BIOS G512LV.314
(04/27/2021)
Keyboard: USB ID 0b05:1866 "ASUSTeK Computer, Inc. N-KEY Device" (the per-key
RGB keyboard controller used on several ROG Strix G-series laptops).
Since a recent kernel update, I can no longer increase/decrease the keyboard
backlight brightness (Fn+F3/F4, and `asusctl -k/-n/-p`). This is specifically
the brightness-*level* control — the separate Aura per-key RGB interface
(colours/effects, and the keyboard-LEDs-on/off power-state toggle via
`asusctl led-pow-1 -a`) still works fine, since that goes through a
different HID path that initializes successfully. It's only the simple
backlight brightness stepping that's broken.
The in-kernel hid-asus driver fails to initialize that backlight at boot:
asus 0003:0B05:1866.0006: using HID for asus::kbd_backlight
asus 0003:0B05:1866.0006: Asus failed to request functions: -75
asus 0003:0B05:1866.0006: Failed to initialize backlight.
-75 is -EBADMSG, returned from the HID feature-report exchange hid-asus
uses to query/initialize the keyboard backlight interface on this device.
Because this fails, no `asus::kbd_backlight` LED class device is ever
created:
$ ls /sys/class/leds/ | grep asus
asus-wireless::airplane
(no asus::kbd_backlight)
asusd (userspace, from the asusctl project) confirms the same gap at
startup, while confirming the separate Aura device is fine:
asusd[1756]: [WARN asusd::ctrl_aura::controller] No asus::kbd_backlight
found for ROG Strix ??
asusd[1756]: [INFO asusd::ctrl_aura::controller] Found 1 Aura devices
And asusctl's own brightness commands fail accordingly:
$ asusctl -k off
Error: org.freedesktop.zbus.Error: org.freedesktop.DBus.Error.Failed:
Missing functionality: No keyboard brightness control found
Note `asusctl -s` (show-supported) still *lists* Off/Low/Med/High as
supported keyboard brightness levels for this model — that's presumably
static per-model capability data, not a live check, so it doesn't notice
the backlight device is actually missing until a brightness command is
actually attempted.
This is a regression — I did not touch my asusctl/asusd config, and nothing
else changed except a run of kernel point-release updates. apt history shows
linux-image-6.12.63+deb13-amd64 was removed and replaced across several
point releases up to the current 6.12.111. I have not yet bisected which
exact point release introduced this (several older kernel images, down to
6.12.48, are still installed and bootable here if that would help narrow
it down — happy to test and follow up with results).
-- Package-specific info:
** Kernel log: boot messages from `journalctl -k -b`, relevant excerpt above.
** Model information
sys_vendor: ASUSTeK COMPUTER INC.
product_name: ROG Strix G512LV_G512LV
product_version: G512LV
bios_vendor: American Megatrends Inc.
bios_version: G512LV.314
board_vendor: ASUSTeK COMPUTER INC.
board_name: G512LV
-- System Information:
Debian Release: 13.7
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 6.12.111+deb13-amd64 (SMP w/16 CPU threads; PREEMPT)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_WARN, TAINT_OOT_MODULE,
TAINT_UNSIGNED_MODULE
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
