Can't control Lenovo laptop screen brightness

Hi, I can’t control the built-in monitors screen brightness; adjusting it with the keyboard or the UI has no effect on the actual display. This is another issue, and possibly related to the following: Connecting external display to laptop - #22 by LukeH

 inxi -Fazy                                      ✔ 
System:
  Kernel: 5.15.41-1-MANJARO arch: x86_64 bits: 64 compiler: gcc v: 12.1.0
    parameters: BOOT_IMAGE=/boot/vmlinuz-5.15-x86_64
    root=UUID=b0c1b620-4a51-4d52-983b-e9774711e237 rw acpi_backlight=vendor
    quiet apparmor=1 security=apparmor udev.log_priority=3
  Desktop: KDE Plasma v: 5.24.5 tk: Qt v: 5.15.4 info: latte-dock
    wm: kwin_x11 vt: 1 dm: SDDM Distro: Manjaro Linux base: Arch Linux
Machine:
  Type: Laptop System: LENOVO product: 82JU v: Legion 5 15ACH6H
    serial: <superuser required> Chassis: type: 10 v: Legion 5 15ACH6H
    serial: <superuser required>
  Mobo: LENOVO model: LNVNB161216 v: SDK0J40709 WIN
    serial: <superuser required> UEFI: LENOVO v: GKCN46WW date: 10/01/2021
Battery:
  ID-1: BAT0 charge: 61.3 Wh (100.0%) condition: 61.3/60.0 Wh (102.2%)
    volts: 17.5 min: 15.4 model: Celxpert L20C4PC0 type: Li-poly
    serial: <filter> status: full cycles: 9
CPU:
  Info: model: AMD Ryzen 5 5600H with Radeon Graphics bits: 64 type: MT MCP
    arch: Zen 3 family: 0x19 (25) model-id: 0x50 (80) stepping: 0
    microcode: 0xA50000C
  Topology: cpus: 1x cores: 6 tpc: 2 threads: 12 smt: enabled cache:
    L1: 384 KiB desc: d-6x32 KiB; i-6x32 KiB L2: 3 MiB desc: 6x512 KiB
    L3: 16 MiB desc: 1x16 MiB
  Speed (MHz): avg: 3326 high: 3963 min/max: 1200/3300 boost: enabled
    scaling: driver: acpi-cpufreq governor: schedutil cores: 1: 3580 2: 3933
    3: 3189 4: 3112 5: 3530 6: 3963 7: 3088 8: 3191 9: 3139 10: 3213 11: 3211
    12: 2764 bogomips: 79081
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm
  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: Retpolines, IBPB: conditional, IBRS_FW,
    STIBP: always-on, RSB filling
  Type: srbds status: Not affected
  Type: tsx_async_abort status: Not affected
Graphics:
  Device-1: NVIDIA GA104M [GeForce RTX 3070 Mobile / Max-Q] vendor: Lenovo
    driver: nvidia v: 510.73.05 alternate: nouveau,nvidia_drm non-free: 515.xx+
    status: current (as of 2022-05) arch: Ampere pcie: gen: 3 speed: 8 GT/s
    lanes: 8 link-max: gen: 4 speed: 16 GT/s lanes: 16 bus-ID: 01:00.0
    chip-ID: 10de:24dd class-ID: 0300
  Device-2: AMD Cezanne vendor: Lenovo driver: amdgpu v: kernel pcie: gen: 3
    speed: 8 GT/s lanes: 16 link-max: gen: 4 speed: 16 GT/s ports: active: eDP-1
    empty: none bus-ID: 05:00.0 chip-ID: 1002:1638 class-ID: 0300
  Display: x11 server: X.Org v: 21.1.3 with: Xwayland v: 22.1.1
    compositor: kwin_x11 driver: X: loaded: amdgpu,nvidia
    unloaded: modesetting,nouveau alternate: fbdev,nv,vesa gpu: amdgpu
    display-ID: :0 screens: 1
  Screen-1: 0 s-res: 4480x1440 s-dpi: 96 s-size: 1182x380mm (46.54x14.96")
    s-diag: 1242mm (48.88")
  Monitor-1: HDMI-1-0 size-res: N/A modes: N/A
  Monitor-2: eDP pos: primary res: 1920x1080 hz: 165 dpi: 142
    size: 344x194mm (13.54x7.64") diag: 395mm (15.55") modes: N/A
  OpenGL: renderer: AMD RENOIR (LLVM 13.0.1 DRM 3.42 5.15.41-1-MANJARO)
    v: 4.6 Mesa 22.0.4 direct render: Yes
Audio:
  Device-1: NVIDIA GA104 High Definition Audio driver: snd_hda_intel v: kernel
    pcie: gen: 3 speed: 8 GT/s lanes: 8 link-max: gen: 4 speed: 16 GT/s
    lanes: 16 bus-ID: 01:00.1 chip-ID: 10de:228b class-ID: 0403
  Device-2: AMD ACP/ACP3X/ACP6x Audio Coprocessor vendor: Lenovo driver: N/A
    alternate: snd_pci_acp3x, snd_rn_pci_acp3x, snd_pci_acp5x pcie: gen: 3
    speed: 8 GT/s lanes: 16 link-max: gen: 4 speed: 16 GT/s bus-ID: 05:00.5
    chip-ID: 1022:15e2 class-ID: 0480
  Device-3: AMD Family 17h/19h HD Audio vendor: Lenovo driver: snd_hda_intel
    v: kernel pcie: gen: 3 speed: 8 GT/s lanes: 16 link-max: gen: 4
    speed: 16 GT/s bus-ID: 05:00.6 chip-ID: 1022:15e3 class-ID: 0403
  Sound Server-1: ALSA v: k5.15.41-1-MANJARO running: yes
  Sound Server-2: JACK v: 1.9.21 running: no
  Sound Server-3: PulseAudio v: 15.0 running: yes
  Sound Server-4: PipeWire v: 0.3.51 running: yes
Network:
  Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet
    vendor: Lenovo driver: r8169 v: kernel pcie: gen: 1 speed: 2.5 GT/s lanes: 1
    port: 2000 bus-ID: 03:00.0 chip-ID: 10ec:8168 class-ID: 0200
  IF: eno1 state: down mac: <filter>
  Device-2: Intel Wi-Fi 6 AX200 driver: iwlwifi v: kernel pcie: gen: 2
    speed: 5 GT/s lanes: 1 bus-ID: 04:00.0 chip-ID: 8086:2723 class-ID: 0280
  IF: wlp4s0 state: up mac: <filter>
  IF-ID-1: br-dcd89bf8ef45 state: up speed: 10000 Mbps duplex: unknown
    mac: <filter>
  IF-ID-2: docker0 state: down mac: <filter>
  IF-ID-3: veth57b56ab state: up speed: 10000 Mbps duplex: full
    mac: <filter>
  IF-ID-4: vethd917899 state: up speed: 10000 Mbps duplex: full
    mac: <filter>
  IF-ID-5: vethffa552b state: up speed: 10000 Mbps duplex: full
    mac: <filter>
Bluetooth:
  Device-1: Intel AX200 Bluetooth type: USB driver: btusb v: 0.8 bus-ID: 3-4:3
    chip-ID: 8087:0029 class-ID: e001
  Report: rfkill ID: hci0 rfk-id: 4 state: up address: see --recommends
Drives:
  Local Storage: total: 476.94 GiB used: 32.77 GiB (6.9%)
  SMART Message: Unable to run smartctl. Root privileges required.
  ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Western Digital
    model: PC SN530 SDBPMPZ-512G-1101 size: 476.94 GiB block-size:
    physical: 512 B logical: 512 B speed: 31.6 Gb/s lanes: 4 type: SSD
    serial: <filter> rev: 21160001 temp: 34.9 C scheme: GPT
Partition:
  ID-1: / raw-size: 476.64 GiB size: 468.09 GiB (98.21%)
    used: 32.76 GiB (7.0%) fs: ext4 dev: /dev/nvme0n1p2 maj-min: 259:2
  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
Swap:
  Alert: No swap data was found.
Sensors:
  System Temperatures: cpu: N/A mobo: N/A gpu: amdgpu temp: 43.0 C
  Fan Speeds (RPM): N/A
Info:
  Processes: 359 Uptime: 1d 7h 21m wakeups: 3 Memory: 13.57 GiB
  used: 4.64 GiB (34.2%) Init: systemd v: 250 tool: systemctl Compilers:
  gcc: 12.1.0 clang: 13.0.1 Packages: pacman: 1349 lib: 342 flatpak: 0
  Shell: Zsh v: 5.9 default: Bash v: 5.1.16 running-in: konsole inxi: 3.3.16

See if this helps any …

No luck:

$ cat /etc/default/grub
...
GRUB_CMDLINE_LINUX_DEFAULT="acpi_backlight=vendor quiet apparmor=1 security=apparmor udev.log_priority=3 amdgpu.backlight=0"
...

Then updating grub:
sudo update-grub

Unfortunately, it doesn’t affect anything.

I’m terribly sorry for not doing this before blurting out my previous response, but after going through pages and pages of my log notes, I came across something that might be of help to you.

Using info from this forum page and @rscm’s posts:

you will see that there are four possibilities for acpi_backlight –

acpi_backlight=video
acpi_backlight=vendor
acpi_backlight=native
acpi_backlight=none

According to my notes, what worked for my Legion 5 Pro laptop was acpi_backlight=video. Perhaps of even more importance to note was that, for me, this only worked in Dynamic mode. I could not get any control of the screen brightness in Discrete mode.

Thanks for the explanation regarding the different options. I am not quite sure how to set/check the dynamic mode. At least setting it to video did nothing for me.