# lspci -k | grep -EA3 'VGA|3D|Display'
00:02.0 VGA compatible controller: Intel Corporation CometLake-U GT2 [UHD Graphics] (rev 02)
	Subsystem: CLEVO/KAPOK Computer CometLake-U GT2 [UHD Graphics]
	Kernel driver in use: i915
	Kernel modules: i915

 cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-6.8.0-101-generic root=UUID=3c3ae400-eaf9-4fec-bcd1-312dd83a63e6 ro quiet splash acpi_os_name=Linux acpi_osi= acpi_backlight=vendor vt.handoff=7

Il faudrait tester :
acpi_backlight=none
video.use_native_backlight=1

A suivre.

Je vois bien le + et - via les commandes claviers … mais pas d’effet.

# acpi_listen 

thermal_zone LNXTHERM:00 00000081 00000000
thermal_zone LNXTHERM:00 00000081 00000000
video/brightnessup BRTUP 00000086 00000000
video/brightnessup BRTUP 00000086 00000000
video/brightnessdown BRTDN 00000087 00000000
video/brightnessdown BRTDN 00000087 00000000

# inxi -Fxxxz
System:
  Kernel: 6.8.0-101-generic arch: x86_64 bits: 64 compiler: gcc v: 13.3.0
    clocksource: tsc
  Desktop: GNOME v: 46.0 tk: GTK v: 3.24.41 wm: gnome-shell
    tools: gsd-screensaver-proxy dm: GDM3 v: 46.2 Distro: Ubuntu 24.04.4 LTS
    (Noble Numbat)
Machine:
  Type: Laptop System: TUXEDO product: TUXEDO v: N/A serial: N/A
    Chassis: Notebook type: 10 serial: N/A
...
Graphics:
  Device-1: Intel CometLake-U GT2 [UHD Graphics] vendor: CLEVO/KAPOK
    driver: i915 v: kernel arch: Gen-9.5 ports: active: HDMI-A-2,eDP-1
    empty: DP-1,HDMI-A-1 bus-ID: 00:02.0 chip-ID: 8086:9b41 class-ID: 0300
  Device-2: Chicony USB2.0 Camera driver: uvcvideo type: USB rev: 2.0
    speed: 480 Mb/s lanes: 1 bus-ID: 1-7:7 chip-ID: 04f2:b649 class-ID: 0e02
  Display: server: X.Org v: 23.2.6 with: Xwayland v: 23.2.6
    compositor: gnome-shell driver: dri: iris gpu: i915 display-ID: :0
    screens: 1
  Screen-1: 0 s-res: 3840x1080 s-dpi: 96 s-size: 1016x285mm (40.00x11.22")
    s-diag: 1055mm (41.54")
  Monitor-1: not-matched mapped: HDMI-2 pos: right res: 1920x1080 hz: 60
    dpi: 81 size: 600x340mm (23.62x13.39") diag: 690mm (27.15") modes: N/A
  Monitor-2: not-matched mapped: eDP-1 pos: primary,left res: 1920x1080
    hz: 60 dpi: 157 size: 310x170mm (12.2x6.69") diag: 354mm (13.92") modes: N/A
  API: EGL v: 1.5 hw: drv: intel iris platforms: device: 0 drv: iris
    device: 1 drv: swrast gbm: drv: iris surfaceless: drv: iris x11: drv: iris
    inactive: wayland
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: intel mesa
    v: 25.2.8-0ubuntu0.24.04.1 glx-v: 1.4 direct-render: yes renderer: Mesa
    Intel UHD Graphics (CML GT2) device-ID: 8086:9b41

# loginctl show-session 2 | grep "wayland"
Type=wayland

# cat /var/log/Xorg.0.log | grep " file"
[     9.729] (--) Log file renamed from "/var/log/Xorg.pid-2950.log" to "/var/log/Xorg.0.log"
[     9.730] Markers: (--) probed, (**) from config file, (==) default setting,
[     9.730] (==) Log file: "/var/log/Xorg.0.log", Time: Sat Feb 22 14:42:32 2025
[    10.212] (II) This device may have been added with another device file.
[    10.228] (II) This device may have been added with another device file.
[    10.459] (II) This device may have been added with another device file.
[  2902.537] (II) Server terminated successfully (0). Closing log file.

$ xbacklight -get
No outputs have backlight property

# find /sys/devices/ -iname edid
/sys/devices/pci0000:00/0000:00:02.0/drm/card1/card1-HDMI-A-1/edid
/sys/devices/pci0000:00/0000:00:02.0/drm/card1/card1-eDP-1/edid
/sys/devices/pci0000:00/0000:00:02.0/drm/card1/card1-HDMI-A-2/edid
/sys/devices/pci0000:00/0000:00:02.0/drm/card1/card1-DP-1/edid

# find /sys/devices/ -iname brightness 
/sys/devices/platform/i8042/serio0/input/input4/input4::capslock/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::scrolllock/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::numlock/brightness
/sys/devices/platform/tuxedo_keyboard/brightness
/sys/devices/pci0000:00/0000:00:1d.1/0000:40:00.0/leds/phy0-led/brightness
/sys/devices/pci0000:00/0000:00:1d.0/0000:3b:00.1/net/enp59s0f1/enp59s0f1-2::lan/brightness
/sys/devices/pci0000:00/0000:00:1d.0/0000:3b:00.1/net/enp59s0f1/enp59s0f1-1::lan/brightness
/sys/devices/pci0000:00/0000:00:1d.0/0000:3b:00.1/net/enp59s0f1/enp59s0f1-0::lan/brightness
/sys/devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4.4/1-4.4:1.0/0003:413C:2110.0002/input/input12/input12::scrolllock/brightness
/sys/devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4.4/1-4.4:1.0/0003:413C:2110.0002/input/input12/input12::numlock/brightness
/sys/devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4.4/1-4.4:1.0/0003:413C:2110.0002/input/input12/input12::capslock/brightness

#  xrandr --listactivemonitors
Monitors: 2
 0: +*eDP-1 1920/310x1080/170+0+0  eDP-1
 1: +HDMI-2 1920/600x1080/340+1920+0  HDMI-2

test :

#  xrandr --output eDP-1 --brightness  0.75

# brightnessctl --list
Available devices:
Device 'input4::capslock' of class 'leds':
	Current brightness: 0 (0%)
	Max brightness: 1

Device 'phy0-led' of class 'leds':
	Current brightness: 0 (0%)
	Max brightness: 1

Device 'input4::scrolllock' of class 'leds':
	Current brightness: 0 (0%)
	Max brightness: 1

Device 'enp59s0f1-2::lan' of class 'leds':
	Current brightness: 0 (0%)
	Max brightness: 255

Device 'enp59s0f1-1::lan' of class 'leds':
	Current brightness: 0 (0%)
	Max brightness: 255

Device 'input12::scrolllock' of class 'leds':
	Current brightness: 0 (0%)
	Max brightness: 1

Device 'input4::numlock' of class 'leds':
	Current brightness: 1 (100%)
	Max brightness: 1

Device 'enp59s0f1-0::lan' of class 'leds':
	Current brightness: 0 (0%)
	Max brightness: 255

Device 'input12::numlock' of class 'leds':
	Current brightness: 1 (100%)
	Max brightness: 1

Device 'input12::capslock' of class 'leds':
	Current brightness: 0 (0%)
	Max brightness: 1

# ddcutil  -d 1 getvcp 10
VCP code 0x10 (Brightness                    ): current value =   100, max value =   100
# ddcutil  -d 1 setvcp 10 80
# ddcutil  -d 1 getvcp 10
VCP code 0x10 (Brightness                    ): current value =    80, max value =   100

# ddcutil detect
Display 1
   I2C bus:  /dev/i2c-2
   DRM connector:           card1-HDMI-A-2
   EDID synopsis:
      Mfg id:               IVM - Iiyama North America
      Model:                PLX2783H
      Product code:         26184  (0x6648)
      Serial number:        1155890322923
      Binary serial number: 2923 (0x00000b6b)
      Manufacture year:     2019,  Week: 3
   VCP version:         2.1

Invalid display
   I2C bus:  /dev/i2c-5
   DRM connector:           card1-eDP-1
   EDID synopsis:
      Mfg id:               AUO - UNK
      Model:                
      Product code:         21565  (0x543d)
      Serial number:        
      Binary serial number: 0 (0x00000000)
      Manufacture year:     2017,  Week: 0
   DDC communication failed
   This is an eDP laptop display. Laptop displays do not support DDC/CI.