Hi Manjaro Community! 
I have had this problem for a while now, searched forums and reddit and tried out as many solutions as I felt comfortable with (I’m still a n00b, I couldn’t even get the 5.4 kernel running 
). The problem is basically, that I can’t change the brightness on my laptop display. It’s constantly 100%. I do see the visual indication of the brightness changing but it doesn’t affect the actual brightness. In /sys/class/backlight the actual_brightness and brightness files do change as well.
As for solutions so far, I have tried…
- …adding acpi_backlight=vendor, native, none and video to GRUB_CMDLINE_LINUX_DEFAULT
- …adding i915.enable_dpcd_backlight=0 to GRUB_CMDLINE_LINUX_DEFAULT
- …changing kernels: I am running Linux 5.10… 5.14 did not change anything… 5.4 did not boot
- …downloading tools like clight (couldn’t get it to work) and xorg-xbacklight (couldn’t get it to work)
None of those changed anything, or I should say I couldn’t use any of them in a way to change something.
I had the same issue on Pop!_OS and TuxOS. I managed to fix it on TuxOS with acpi_backlight=vendor.
Can someone either give me a detailed answer to how to fix this (haha, if only)? If not does somebody have more ideas to what I can try? Should I try to install the 5.4 kernel before I do anything else?
inxi output
System:
Kernel: 5.10.56-1-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0
parameters: BOOT_IMAGE=/boot/vmlinuz-5.10-x86_64
root=UUID=fc8f40cf-985f-4b4e-ad65-74690075cd48 rw quiet splash
acpi_backlight=video
Desktop: KDE Plasma 5.22.4 tk: Qt 5.15.2 wm: kwin_x11 vt: 1 dm: SDDM
Distro: Manjaro Linux base: Arch Linux
Machine:
Type: Laptop System: TUXEDO product: TUXEDO Polaris AMD Gen2 (REN)
v: Standard serial: <filter>
Mobo: NB02 model: GMxNGxx v: Standard serial: <filter>
UEFI: American Megatrends v: N.1.05A02 date: 05/28/2021
Battery:
ID-1: BAT0 charge: 62.3 Wh (100.0%) condition: 62.3/62.3 Wh (100.0%)
volts: 17.3 min: 15.2 model: standard type: Li-ion serial: <filter>
status: Full
Memory:
RAM: total: 30.85 GiB used: 3.23 GiB (10.5%)
RAM Report: permissions: Unable to run dmidecode. Root privileges required.
CPU:
Info: 8-Core model: AMD Ryzen 7 4800H with Radeon Graphics bits: 64
type: MT MCP arch: Zen 2 family: 17 (23) model-id: 60 (96) stepping: 1
microcode: 8600106 cache: L2: 4 MiB bogomips: 92657
Speed: 1397 MHz min/max: 1400/2900 MHz boost: enabled Core speeds (MHz):
1: 1397 2: 1397 3: 1397 4: 1396 5: 1397 6: 1395 7: 1397 8: 1396 9: 1403
10: 1427 11: 1397 12: 1398 13: 1527 14: 1416 15: 1397 16: 1389
Flags: 3dnowprefetch abm adx aes aperfmperf apic arat avic avx avx2 bmi1
bmi2 bpext cat_l3 cdp_l3 clflush clflushopt clwb clzero cmov cmp_legacy
constant_tsc cpb cpuid cqm cqm_llc cqm_mbm_local cqm_mbm_total cqm_occup_llc
cr8_legacy cx16 cx8 de decodeassists extapic extd_apicid f16c flushbyasid
fma fpu fsgsbase fxsr fxsr_opt ht hw_pstate ibpb ibrs ibs irperf lahf_lm
lbrv lm mba mca mce misalignsse mmx mmxext monitor movbe msr mtrr mwaitx
nonstop_tsc nopl npt nrip_save nx osvw overflow_recov pae pat pausefilter
pclmulqdq pdpe1gb perfctr_core perfctr_llc perfctr_nb pfthreshold pge pni
popcnt pse pse36 rdpid rdpru rdrand rdseed rdt_a rdtscp rep_good sep sha_ni
skinit smap smca smep ssbd sse sse2 sse4_1 sse4_2 sse4a ssse3 stibp succor
svm svm_lock syscall tce topoext tsc tsc_scale umip v_vmsave_vmload vgif
vmcb_clean vme vmmcall wbnoinvd wdt xgetbv1 xsave xsavec xsaveerptr xsaveopt
xsaves
Vulnerabilities: Type: itlb_multihit status: Not affected
Type: l1tf status: Not affected
Type: mds status: Not affected
Type: meltdown status: Not affected
Type: spec_store_bypass
mitigation: Speculative Store Bypass disabled via prctl and seccomp
Type: spectre_v1
mitigation: usercopy/swapgs barriers and __user pointer sanitization
Type: spectre_v2 mitigation: Full AMD retpoline, IBPB: conditional, IBRS_FW,
STIBP: conditional, RSB filling
Type: srbds status: Not affected
Type: tsx_async_abort status: Not affected
Graphics:
Device-1: NVIDIA GA106M [GeForce RTX 3060 Mobile / Max-Q]
vendor: Tongfang Hongkong Limited driver: nvidia v: 470.57.02
alternate: nouveau,nvidia_drm bus-ID: 01:00.0 chip-ID: 10de:2520
class-ID: 0300
Device-2: AMD Renoir vendor: Tongfang Hongkong Limited driver: amdgpu
v: kernel bus-ID: 06:00.0 chip-ID: 1002:1636 class-ID: 0300
Device-3: Chicony HD Webcam type: USB driver: uvcvideo bus-ID: 1-4:4
chip-ID: 04f2:b71a class-ID: 0e02 serial: <filter>
Display: x11 server: X .Org 1.20.13 compositor: kwin_x11 driver:
loaded: amdgpu,ati,nvidia unloaded: modesetting,nouveau
alternate: fbdev,nv,vesa display-ID: :0 screens: 1
Screen-1: 0 s-res: 2560x1440 s-dpi: 96 s-size: 677x381mm (26.7x15.0")
s-diag: 777mm (30.6")
Monitor-1: eDP res: 2560x1440 hz: 165 dpi: 189 size: 344x194mm (13.5x7.6")
diag: 395mm (15.5")
OpenGL: renderer: AMD RENOIR (DRM 3.40.0 5.10.56-1-MANJARO LLVM 12.0.1)
v: 4.6 Mesa 21.1.6 direct render: Yes
Audio:
Device-1: AMD Raven/Raven2/FireFlight/Renoir Audio Processor
vendor: Tongfang Hongkong Limited driver: N/A
alternate: snd_pci_acp3x, snd_rn_pci_acp3x bus-ID: 06:00.5
chip-ID: 1022:15e2 class-ID: 0480
Device-2: AMD Family 17h HD Audio vendor: Tongfang Hongkong Limited
driver: snd_hda_intel v: kernel bus-ID: 06:00.6 chip-ID: 1022:15e3
class-ID: 0403
Sound Server-1: ALSA v: k5.10.56-1-MANJARO running: yes
Sound Server-2: JACK v: 1.9.19 running: no
Sound Server-3: PulseAudio v: 15.0 running: yes
Sound Server-4: PipeWire v: 0.3.33 running: no
Network:
Device-1: Realtek RTL8125 2.5GbE vendor: Tongfang Hongkong Limited
driver: r8169 v: kernel port: e000 bus-ID: 02:00.0 chip-ID: 10ec:8125
class-ID: 0200
IF: enp2s0 state: down mac: <filter>
Device-2: Intel Wi-Fi 6 AX200 driver: iwlwifi v: kernel port: e000
bus-ID: 04:00.0 chip-ID: 8086:2723 class-ID: 0280
IF: wlp4s0 state: up mac: <filter>
IP v4: <filter> type: dynamic noprefixroute scope: global
broadcast: <filter>
IP v6: <filter> type: noprefixroute scope: link
WAN IP: <filter>
Bluetooth:
Device-1: Intel AX200 Bluetooth type: USB driver: btusb v: 0.8 bus-ID: 3-4:4
chip-ID: 8087:0029 class-ID: e001
Report: rfkill ID: hci0 rfk-id: 1 state: up address: see --recommends
Logical:
Message: No logical block device data found.
RAID:
Message: No RAID data found.
Drives:
Local Storage: total: 931.51 GiB used: 50.13 GiB (5.4%)
SMART Message: Unable to run smartctl. Root privileges required.
ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Samsung model: SSD 980 1TB
size: 931.51 GiB block-size: physical: 512 B logical: 512 B speed: 31.6 Gb/s
lanes: 4 type: SSD serial: <filter> rev: 1B4QFXO7 temp: 35.9 C scheme: GPT
Message: No optical or floppy data found.
Partition:
ID-1: / raw-size: 897.28 GiB size: 882.12 GiB (98.31%)
used: 50.13 GiB (5.7%) fs: ext4 dev: /dev/nvme0n1p2 maj-min: 259:2
label: N/A uuid: fc8f40cf-985f-4b4e-ad65-74690075cd48
ID-2: /boot/efi raw-size: 300 MiB size: 299.4 MiB (99.80%)
used: 288 KiB (0.1%) fs: vfat dev: /dev/nvme0n1p1 maj-min: 259:1
label: NO_LABEL uuid: 86FE-A993
Swap:
Kernel: swappiness: 60 (default) cache-pressure: 100 (default)
ID-1: swap-1 type: partition size: 33.94 GiB used: 0 KiB (0.0%) priority: -2
dev: /dev/nvme0n1p3 maj-min: 259:3 label: N/A
uuid: fd1fc023-ec45-406a-a33b-ca2c682143fc
Unmounted:
Message: No unmounted partitions found.
USB:
Hub-1: 1-0:1 info: Full speed (or root) Hub ports: 4 rev: 2.0
speed: 480 Mb/s chip-ID: 1d6b:0002 class-ID: 0900
Hub-2: 1-2:3 info: Genesys Logic Hub ports: 2 rev: 2.1 speed: 480 Mb/s
chip-ID: 05e3:0610 class-ID: 0900
Device-1: 1-4:4 info: Chicony HD Webcam type: Video driver: uvcvideo
interfaces: 4 rev: 2.0 speed: 480 Mb/s power: 500mA chip-ID: 04f2:b71a
class-ID: 0e02 serial: <filter>
Hub-3: 2-0:1 info: Full speed (or root) Hub ports: 2 rev: 3.1 speed: 10 Gb/s
chip-ID: 1d6b:0003 class-ID: 0900
Device-1: 2-1:3 info: Realtek Card Reader type: Mass Storage
driver: usb-storage interfaces: 1 rev: 3.0 speed: 5 Gb/s power: 800mA
chip-ID: 0bda:0316 class-ID: 0806 serial: <filter>
Hub-4: 2-2:2 info: Genesys Logic USB3.2 Hub ports: 2 rev: 3.2 speed: 5 Gb/s
chip-ID: 05e3:0620 class-ID: 0900
Hub-5: 3-0:1 info: Full speed (or root) Hub ports: 4 rev: 2.0
speed: 480 Mb/s chip-ID: 1d6b:0002 class-ID: 0900
Device-1: 3-2:2 info: Dell Optical 5-Button Wheel Mouse type: Mouse
driver: hid-generic,usbhid interfaces: 1 rev: 2.0 speed: 1.5 Mb/s
power: 100mA chip-ID: 413c:3016 class-ID: 0301
Hub-6: 3-3:3 info: Genesys Logic Hub ports: 4 rev: 2.1 speed: 480 Mb/s
power: 500mA chip-ID: 05e3:0608 class-ID: 0900
Device-1: 3-4:4 info: Intel AX200 Bluetooth type: Bluetooth driver: btusb
interfaces: 2 rev: 2.0 speed: 12 Mb/s power: 100mA chip-ID: 8087:0029
class-ID: e001
Hub-7: 4-0:1 info: Full speed (or root) Hub ports: 2 rev: 3.1 speed: 10 Gb/s
chip-ID: 1d6b:0003 class-ID: 0900
Sensors:
System Temperatures: cpu: 58.5 C mobo: 49.0 C gpu: amdgpu temp: 42.0 C
Fan Speeds (RPM): N/A
Info:
Processes: 327 Uptime: 31m wakeups: 1 Init: systemd v: 248 tool: systemctl
Compilers: gcc: 11.1.0 Packages: pacman: 1293 lib: 361 flatpak: 0
Shell: Bash v: 5.1.8 running-in: yakuake inxi: 3.3.06
and all the data requested here:
00-keyboard.conf
# Read and parsed by systemd-localed. It's probably wise not to edit this file
# manually too freely.
Section "InputClass"
Identifier "system-keyboard"
MatchIsKeyboard "on"
Option "XkbLayout" "de"
EndSection
30-touchpad.conf
Section "InputClass"
Identifier "touchpad"
Driver "libinput"
MatchIsTouchpad "on"
Option "Tapping" "on"
EndSection
90-mhwd.conf
##
## Generated by mhwd - Manjaro Hardware Detection
##
I feel like I should also add /etc/default/grub since I messed around with it a lot.
/etc/default/grub
GRUB_DEFAULT=saved
GRUB_TIMEOUT=5
GRUB_TIMEOUT_STYLE=hidden
GRUB_DISTRIBUTOR="Manjaro"
GRUB_CMDLINE_LINUX="reboot=acpi"
GRUB_CMDLINE_LINUX_DEFAULT="quiet apparmor=1 security=apparmor udev.log_priority=3 acpi_backlight=vendor"
# If you want to enable the save default function, uncomment the following
# line, and set GRUB_DEFAULT to saved.
GRUB_SAVEDEFAULT=true
# Preload both GPT and MBR modules so that they are not missed
GRUB_PRELOAD_MODULES="part_gpt part_msdos"
# Uncomment to enable booting from LUKS encrypted devices
#GRUB_ENABLE_CRYPTODISK=y
# Uncomment to use basic console
GRUB_TERMINAL_INPUT=console
# Uncomment to disable graphical terminal
#GRUB_TERMINAL_OUTPUT=console
# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command 'videoinfo'
GRUB_GFXMODE=auto
# Uncomment to allow the kernel use the same resolution used by grub
GRUB_GFXPAYLOAD_LINUX=keep
# Uncomment if you want GRUB to pass to the Linux kernel the old parameter
# format "root=/dev/xxx" instead of "root=/dev/disk/by-uuid/xxx"
#GRUB_DISABLE_LINUX_UUID=true
# Uncomment to disable generation of recovery mode menu entries
GRUB_DISABLE_RECOVERY=true
# Uncomment this option to enable os-prober execution in the grub-mkconfig command
GRUB_DISABLE_OS_PROBER=false
# Uncomment and set to the desired menu colors. Used by normal and wallpaper
# modes only. Entries specified as foreground/background.
GRUB_COLOR_NORMAL="light-gray/black"
GRUB_COLOR_HIGHLIGHT="green/black"
# Uncomment one of them for the gfx desired, a image background or a gfxtheme
#GRUB_BACKGROUND="/usr/share/grub/background.png"
GRUB_THEME="/usr/share/grub/themes/manjaro/theme.txt"
# Uncomment to get a beep at GRUB start
#GRUB_INIT_TUNE="480 440 1"
# Uncomment to ensure that the root filesystem is mounted read-only so that
# systemd-fsck can run the check automatically. We use 'fsck' by default, which
# needs 'rw' as boot parameter, to avoid delay in boot-time. 'fsck' needs to be
# removed from 'mkinitcpio.conf' to make 'systemd-fsck' work.
# See also Arch-Wiki: https://wiki.archlinux.org/index.php/Fsck#Boot_time_checking
#GRUB_ROOT_FS_RO=true
After the most recent system updates and a restart the brightness could just be controlled again.