RGB Keyboard Control Not Working on Acer Nitro ANV16S-41

[mahmudovwork25]

RGB Keyboard Control Not Working on Acer Nitro ANV16S-41

Description

The facer module loads successfully on my Acer Nitro ANV16S-41 and creates both /dev/acer-gkbbl-0 and /dev/acer-gkbbl-static-0 character devices, but none of the RGB commands have any effect on the keyboard backlight. The keyboard stays in its default wave RGB mode (firmware default).

I tested all available modes (static, breath, neon, wave, shifting, zoom) and also tried writing directly to the character devices — none of them change the keyboard lighting.

System Information

Info	Value
Laptop Model	Acer Nitro ANV16S-41
Board Name	BRZ_SKF
BIOS Version	V1.04 (06/18/2025)
Kernel	6.19.8-zen1-1-zen (Arch Linux)
Module Version	Latest from main branch

What I Tried

1. Standard mode commands (all had no effect)

# Static mode - all 4 zones
sudo python facer_rgb.py -m 0 -z 1 -b 100 -cR 255 -cG 0 -cB 0
sudo python facer_rgb.py -m 0 -z 2 -b 100 -cR 0 -cG 255 -cB 0
sudo python facer_rgb.py -m 0 -z 3 -b 100 -cR 0 -cG 0 -cB 255
sudo python facer_rgb.py -m 0 -z 4 -b 100 -cR 255 -cG 255 -cB 0

# Breath mode
sudo python facer_rgb.py -m 1 -s 4 -b 100 -cR 255 -cG 0 -cB 255

# Neon mode
sudo python facer_rgb.py -m 2 -s 3 -b 100

# Wave mode (speed 0)
sudo python facer_rgb.py -m 3 -s 0 -b 100

2. Direct device writes (no effect)

sudo python3 -c "
data = bytes([0x01, 255, 255, 255])
with open('/dev/acer-gkbbl-static-0', 'wb') as f:
    f.write(data)
data2 = bytes([0,0,100,0,0,0,0,0,0,1,0,0,0,0,0,0])
with open('/dev/acer-gkbbl-0', 'wb') as f:
    f.write(data2)
"

3. Tried loading with predator_v4=1 (no effect)

sudo rmmod facer
sudo insmod /opt/turbo-fan/src/facer.ko predator_v4=1

dmesg Output

facer: Acer Laptop ACPI-WMI Extras
facer: Function bitmap for Communication Button: 0x1
facer: Unknown function number - 8 - 1
facer: Unknown function number - 9 - 1
facer: Unknown function number - 8 - 1

The "Unknown function number" errors (8 and 9) suggest this model uses WMI function numbers that the module doesn't currently handle.

Module Parameters (with predator_v4=1)

predator_v4: Y
force_caps: -1
force_series: 0

HID Devices

0018:06CB:CFE4 - SYNA7DAB:00 (Synaptics touchpad)
0018:0CF2:5130 - ENEK5130:00 (unknown)
0018:1025:174B - Acer device (possibly keyboard controller)

Note: No ITE 8291 USB device found (no 048d vendor in lsusb). The keyboard appears to use I2C HID rather than USB HID.

lsusb

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 13d3:3607 IMC Networks Wireless_Device
Bus 002-008: Only root hubs (no USB keyboard controller)

Additional Notes

• The keyboard has a 4-zone RGB backlight that defaults to a wave/rainbow effect in firmware
• This wave effect runs even without any OS-level drivers (was present from the first Linux boot)
• On Windows, NitroSense (or Acer QuickPanel) controls the RGB
• The character devices /dev/acer-gkbbl-0 and /dev/acer-gkbbl-static-0 are created successfully, which means the WMI GUIDs are detected, but the actual WMI method calls don't appear to reach the keyboard controller

I'd love to help test any patches or provide additional debug info if needed!

[mahmudovwork25]

Update: I found issue #285 which confirms the AN16-41 (non-Slim) works out of the box with all RGB modes. My ANV16S-41 (Slim variant - thinner chassis) does not respond to any RGB commands despite the module loading successfully and /dev/acer-gkbbl-0 + /dev/acer-gkbbl-static-0 devices being created.

The "S" (Slim) variant likely uses different WMI method IDs for keyboard backlight control. The non-Slim AN16-41 and my ANV16S-41 share the same CPU platform but have different motherboards (mine is BRZ_SKF).

I tested with both predator_v4=0 and predator_v4=1 - neither had any effect. The keyboard remains in its firmware-default wave RGB mode.

[0x189D7997]

@mahmudovwork25
I am curious if the script from here works for ANV16S-41, might be helpful:
0x7375646F/Linuwu-Sense#65
It is a different project but I had to figure out the new rgb logic from scratch anyway.