ASUS TUF Gaming A16 (FA608WV) on Linux
Screen Brightness & Keyboard Backlight — A Dual-GPU ACPI Case Study
System Overview
I am running Arch Linux on an ASUS TUF Gaming A16 (FA608WV) with the following configuration:
CPU / iGPU: AMD Ryzen AI 9 HX (Radeon 880M / 890M)
dGPU: NVIDIA RTX 4060 (Laptop)
GPU topology: Muxless dual-GPU system
Internal display panel is physically wired to the AMD iGPU
NVIDIA dGPU is used for rendering/offload
Display server: X11
Window manager: i3wm
Kernel: Linux 6.17.9-arch1-1
BIOS: FA608WV.305 (2024-11-25)
I run NVIDIA as the primary rendering provider (NVIDIA as Provider 0 in Xorg), which is a common setup for performance-focused Linux users.
Problem Summary
I am facing two related but distinct hardware control issues on Linux:
Screen hardware brightness control is unreliable / intermittent
Keyboard backlight does not work at all
❯ hostnamectl
Static hostname: 9HX
Icon name: computer-laptop
Chassis: laptop 💻
Chassis Asset Tag: No Asset Tag
Machine ID: 480d70398f004aa8b214c37b9314a6b2
Boot ID: 3efa217afce64be188aa57f18a2efa83
Operating System: Arch Linux
Kernel: Linux 6.17.9-arch1-1
Architecture: x86-64
Hardware Vendor: ASUSTeK COMPUTER INC.
Hardware Model: ASUS TUF Gaming A16 FA608WV_FA608WV
Hardware Version: 1.0
Firmware Version: FA608WV.305
Firmware Date: Mon 2024-11-25
Firmware Age: 1y 2month
Screen Brightness: Root Cause Only a single backlight interface is exposed:
Despite the internal panel being driven by the AMD iGPU, the kernel does not register the AMD DRM backlight (amdgpu_bl0). This forces Linux to fall back to an ACPI / Embedded Controller (EC) backlight path exposed via NVIDIA WMI.
This EC-based backlight path is:
Firmware-dependent
Power-state sensitive
Intermittent across boots and suspend/resume
As a result, hardware brightness control works inconsistently and tools like xbacklight are unusable because no DRM backlight exists.
❯ ls -l /sys/class/backlight/
total 0
lrwxrwxrwx 1 root root 0 Jan 25 19:43 nvidia_wmi_ec_backlight -> ../../devices/pci0000:00/PNP0C14:00/wmi_bus/wmi_bus-PNP0C14:00/603E9613-EF25-4338-A3D0-C46177516DB7-0/backlight/nvidia_wmi_ec_backlight
Rendering path:
❯ glxinfo | grep "OpenGL renderer"
OpenGL renderer string: NVIDIA GeForce RTX 4060 Laptop GPU/PCIe/SSE2
Xorg provider state:
❯ xrandr --listproviders
Providers: number : 2
Provider 0: id: 0x1b7 cap: 0x1, Source Output crtcs: 4 outputs: 4 associated providers: 1 name:NVIDIA-0
Provider 1: id: 0x1eb cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 4 outputs: 9 associated providers: 1 name:modesetting
GPU layout confirms a classic AMD-panel / NVIDIA-render configuration:
❯ lspci -nn | grep -E "VGA|3D|Display"
64:00.0 VGA compatible controller [0300]: NVIDIA Corporation AD107M [GeForce RTX 4060 Max-Q / Mobile] [10de:28e0] (rev a1)
65:00.0 Display controller [0380]: Advanced Micro Devices, Inc. [AMD/ATI] Strix [Radeon 880M / 890M] [1002:150e] (rev c1)
GPU layout confirms a classic AMD-panel / NVIDIA-render configuration:
❯ lspci -k | grep -A3 -E "VGA|Display"
pcilib: Error reading /sys/bus/pci/devices/0000:00:08.3/label: Operation not permitted
64:00.0 VGA compatible controller: NVIDIA Corporation AD107M [GeForce RTX 4060 Max-Q / Mobile] (rev a1)
Subsystem: ASUSTeK Computer Inc. Device 3818
Kernel driver in use: nvidia
Kernel modules: nouveau, nvidia_drm, nvidia
--
65:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Strix [Radeon 880M / 890M] (rev c1)
Subsystem: ASUSTeK Computer Inc. Device 3818
Kernel driver in use: amdgpu
Kernel modules: amdgpu
Keyboard Backlight: Root Cause
The kernel exposes a keyboard backlight interface:
/sys/class/leds/asus::kbd_backlight
However, writing brightness values produces no physical effect. This indicates that while the interface exists, no functional EC command is mapped for the FA608WV model. In other words, the required ASUS EC/WMI quirk for keyboard backlight control is missing.
Because this is a kernel-level issue, userspace tools such as asusctl cannot fix it.
Required Kernel Support (Conclusion)
For the ASUS TUF Gaming A16 (FA608WV, 2025) to work reliably on Linux, the most important fixes are required at the kernel level, not in window managers or userspace tools. The primary issue lies in the drm/amdgpu subsystem, where the kernel currently skips registering the AMD DRM backlight (amdgpu_bl0) despite the internal display panel being physically wired to the AMD iGPU. This forces Linux to fall back to an ACPI/EC-based backlight path that is firmware-dependent and unstable. To ensure consistent screen brightness control, the kernel needs a deterministic backlight selection policy—either by restoring AMD DRM backlight registration on this model or by introducing a DMI-based exception so that AMD-driven panels always expose a native DRM backlight interface.
The second required update concerns ASUS EC/WMI support in asus-wmi / asus-nb-wmi. Although the kernel exposes a keyboard backlight device (asus::kbd_backlight), it performs no actual EC action on the FA608WV, indicating a missing model-specific EC quirk. Without this, keyboard backlight control cannot function regardless of userspace configuration or tools like asusctl. Once these kernel-level fixes are in place—restoring AMD DRM backlight and adding the correct EC mapping for keyboard lighting—userspace utilities and desktop environments will work consistently without workarounds. Until then, brightness and keyboard lighting on this 2025-era laptop should be expected to remain best-effort rather than fully reliable.
On ASUS TUF Gaming A16 (FA608WV), the kernel skips AMD DRM backlight registration despite the panel being AMD-driven and exposes a non-functional ASUS EC keyboard backlight; restoring deterministic AMD backlight handling and adding a model-specific EC/WMI quirk are required for reliable brightness and keyboard lighting support.
good luck for those who purchased this laptop for Linux use case...me spent lot of money on this laptop and got noting to do other than waiting for an early update for this model..
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