Can't adjust screen brightness (Lenovo Laptop, NVIDIA, XFCE)

Hello, i have the exact same problem here with a similar environment (same Lenovo Legion laptop + Nvidia + XFCE), similar configuration files (main difference is that i’m using kernel 5.4) and same content in /sys/class/backlight when using acpi_backlight=vendor.
Did you manage to fix it ?

Is there a way to rename the /sys/class/backlight/ideapad to nvidia_0 ?
I could not use mv or ln -s on it.

I notice a version mismatch between mhwd -li (which gives video-nvidia-440xx) and the driver i am supposed to be using (linux54-nvidia-450xx). Could it be related to the issue ?

Hello,

After my manjaro updated today screen brightness seems to be set to maximum and neither my keyboard nor the slider under setting works anymore.

Here are some infos on my machine. If you need more I’ll try to deliver it.

System:    Kernel: 5.9.8-2-MANJARO x86_64 bits: 64 compiler: gcc v: 10.2.0 Desktop: GNOME 3.38.1 tk: GTK 3.24.23 
           wm: gnome-shell dm: GDM 3.38.1 Distro: Manjaro Linux 
Machine:   Type: Laptop System: Dell product: XPS 15 9570 v: N/A serial: <filter> Chassis: type: 10 serial: <filter> 
           Mobo: Dell model: 0JVFJ2 v: A00 serial: <filter> UEFI [Legacy]: Dell v: 1.16.2 date: 04/21/2020 
Battery:   ID-1: BAT0 charge: 60.1 Wh condition: 81.9/97.0 Wh (84%) volts: 11.5/11.4 model: SMP DELL GPM0365 type: Li-ion 
           serial: <filter> status: Discharging 
Memory:    RAM: total: 7.15 GiB used: 1.77 GiB (24.8%) 
           RAM Report: permissions: Unable to run dmidecode. Root privileges required. 
CPU:       Info: Quad Core model: Intel Core i5-8300H bits: 64 type: MT MCP arch: Kaby Lake rev: A L2 cache: 8192 KiB 
           bogomips: 36812 
           Speed: 800 MHz min/max: 800/4000 MHz Core speeds (MHz): 1: 800 2: 800 3: 800 4: 800 5: 800 6: 800 7: 800 8: 801 
           Flags: 3dnowprefetch abm acpi adx aes aperfmperf apic arat arch_perfmon art avx avx2 bmi1 bmi2 bts clflush 
           clflushopt cmov constant_tsc cpuid cpuid_fault cx16 cx8 de ds_cpl dtes64 dtherm dts epb ept ept_ad erms est f16c 
           flexpriority flush_l1d fma fpu fsgsbase fxsr ht hwp hwp_act_window hwp_epp hwp_notify ibpb ibrs ida intel_pt 
           invpcid invpcid_single lahf_lm lm mca mce md_clear mmx monitor movbe mpx msr mtrr nonstop_tsc nopl nx pae pat pbe 
           pcid pclmulqdq pdcm pdpe1gb pebs pge pln pni popcnt pse pse36 pti pts rdrand rdseed rdtscp rep_good sdbg sep smap 
           smep ss ssbd sse sse2 sse4_1 sse4_2 ssse3 stibp syscall tm tm2 tpr_shadow tsc tsc_adjust tsc_deadline_timer vme vmx 
           vnmi vpid x2apic xgetbv1 xsave xsavec xsaveopt xsaves xtopology xtpr 
Graphics:  Device-1: Intel UHD Graphics 630 vendor: Dell driver: i915 v: kernel bus ID: 00:02.0 chip ID: 8086:3e9b 
           Device-2: NVIDIA GP107M [GeForce GTX 1050 Mobile] driver: nouveau v: kernel bus ID: 01:00.0 chip ID: 10de:1c8d 
           Device-3: Microdia Integrated_Webcam_HD type: USB driver: uvcvideo bus ID: 1-12:4 chip ID: 0c45:671d 
           Display: x11 server: X.org 1.20.9 compositor: gnome-shell driver: modesetting 
           alternate: fbdev,intel,nouveau,nv,vesa resolution: <xdpyinfo missing> 
           OpenGL: renderer: Mesa Intel UHD Graphics 630 (CFL GT2) v: 4.6 Mesa 20.2.2 direct render: Yes 
Audio:     Device-1: Intel Cannon Lake PCH cAVS vendor: Dell driver: snd_hda_intel v: kernel bus ID: 00:1f.3 
           chip ID: 8086:a348 
           Sound Server: ALSA v: k5.9.8-2-MANJARO 
Network:   Device-1: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter vendor: Bigfoot Networks driver: ath10k_pci 
           v: kernel port: 3000 bus ID: 3b:00.0 chip ID: 168c:003e 
           IF: wlp59s0 state: up mac: <filter> 
           IP v4: <filter> type: dynamic noprefixroute scope: global broadcast: <filter> 
           IP v6: <filter> type: dynamic noprefixroute scope: global 
           IP v6: <filter> type: noprefixroute scope: link 
           Device-2: Qualcomm Atheros QCA61x4 Bluetooth 4.0 type: USB driver: btusb bus ID: 1-4:2 chip ID: 0cf3:e300 
           WAN IP: <filter> 
Drives:    Local Storage: total: 57.30 GiB used: 34.74 GiB (60.6%) 
           ID-1: /dev/sda type: USB vendor: SanDisk model: Ultra Luxe size: 57.30 GiB serial: <filter> rev: 1.00 scheme: GPT 
           Message: No Optical or Floppy data was found. 
RAID:      Hardware-1: Intel 82801 Mobile SATA Controller [RAID mode] driver: ahci v: 3.0 port: 4060 bus ID: 00:17.0 
           chip ID: 8086.282a rev: 10 
Partition: ID-1: / size: 23.91 GiB used: 16.13 GiB (67.5%) fs: ext4 dev: /dev/sda2 label: N/A 
           uuid: 83300378-9e6b-42ab-a364-88a344b99ce3 
           ID-2: /boot size: 511.0 MiB used: 149.5 MiB (29.3%) fs: vfat dev: /dev/sda1 label: N/A uuid: 6864-FAF5 
           ID-3: /home size: 31.62 GiB used: 18.47 GiB (58.4%) fs: ext4 dev: /dev/dm-0 label: N/A 
           uuid: f67ebcbc-769d-406f-a958-d582dc4ff3a9 
Swap:      Alert: No Swap data was found. 
Unmounted: ID-1: /dev/sda3 size: 32.38 GiB fs: crypto_luks label: N/A uuid: ae6eaac8-a2f9-468f-a12e-d33184ca3973 
           ID-2: /dev/sda4 size: 8.9 MiB fs: <superuser/root required> label: N/A uuid: N/A 
USB:       Hub: 1-0:1 info: Full speed (or root) Hub ports: 16 rev: 2.0 speed: 480 Mb/s chip ID: 1d6b:0002 
           Device-1: 1-2:5 info: Pixart Imaging Optical Mouse type: Mouse driver: hid-generic,usbhid interfaces: 1 rev: 2.0 
           speed: 1.5 Mb/s chip ID: 093a:2510 
           Device-2: 1-4:2 info: Qualcomm Atheros QCA61x4 Bluetooth 4.0 type: Bluetooth driver: btusb interfaces: 2 rev: 2.0 
           speed: 12 Mb/s chip ID: 0cf3:e300 
           Device-3: 1-7:3 info: Shenzhen Goodix Fingerprint Reader type: Abstract (modem),CDC-Data driver: cdc_acm 
           interfaces: 2 rev: 2.0 speed: 12 Mb/s chip ID: 27c6:5395 serial: <filter> 
           Device-4: 1-12:4 info: Microdia Integrated_Webcam_HD type: Video driver: uvcvideo interfaces: 2 rev: 2.0 
           speed: 480 Mb/s chip ID: 0c45:671d 
           Hub: 2-0:1 info: Full speed (or root) Hub ports: 10 rev: 3.1 speed: 10 Gb/s chip ID: 1d6b:0003 
           Device-1: 2-1:2 info: SanDisk Ultra Luxe type: Mass Storage driver: usb-storage interfaces: 1 rev: 3.2 
           speed: 5 Gb/s chip ID: 0781:55a3 serial: <filter> 
Sensors:   System Temperatures: cpu: 36.0 C mobo: N/A gpu: nouveau temp: 31.0 C 
           Fan Speeds (RPM): cpu: 0 fan-2: 0 
Info:      Processes: 260 Uptime: 14m Init: systemd v: 246 Compilers: gcc: N/A Packages: 1321 pacman: 1315 flatpak: 6 
           Shell: Zsh v: 5.8 running in: gnome-terminal inxi: 3.1.08

Yeah, after updating to kernel 5.9.8-2 my screen brightness was also fixed on my Dell XPS 13 laptop. 100% brightness when connected to a power supply, and 20% when running on the battery.

Here is my inxi -Fxxz output:

System:
  Kernel: 5.9.8-2-MANJARO x86_64 bits: 64 compiler: gcc v: 10.2.0
  Desktop: Xfce 4.14.3 tk: Gtk 3.24.23 wm: xfwm4 dm: LightDM Distro: Manjaro Linux
Machine:
  Type: Laptop System: Dell product: XPS 13 9370 v: N/A serial: <filter> Chassis:
  type: 10 serial: <filter>
  Mobo: Dell model: 0F6P3V v: A00 serial: <filter> UEFI: Dell v: 1.13.1
  date: 07/08/2020
Battery:
  ID-1: BAT0 charge: 47.1 Wh condition: 50.3/52.0 Wh (97%) volts: 8.3/7.6
  model: SMP DELL G8VCF6C serial: <filter> status: Discharging
CPU:
  Info: Quad Core model: Intel Core i7-8550U bits: 64 type: MT MCP arch: Kaby Lake
  rev: A L2 cache: 8192 KiB
  flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 32012
  Speed: 900 MHz min/max: 400/4000 MHz Core speeds (MHz): 1: 900 2: 900 3: 900
  4: 900 5: 900 6: 900 7: 900 8: 900
Graphics:
  Device-1: Intel UHD Graphics 620 vendor: Dell driver: i915 v: kernel
  bus ID: 00:02.0 chip ID: 8086:5917
  Device-2: Realtek Integrated_Webcam_HD type: USB driver: uvcvideo bus ID: 1-5:3
  chip ID: 0bda:58f4
  Display: x11 server: X.Org 1.20.9 driver: intel unloaded: modesetting
  alternate: fbdev,vesa s-res: 1920x1080 s-dpi: 96
  OpenGL: renderer: Mesa Intel UHD Graphics 620 (KBL GT2) v: 4.6 Mesa 20.2.2
  direct render: Yes
Audio:
  Device-1: Intel Sunrise Point-LP HD Audio vendor: Dell driver: snd_hda_intel
  v: kernel bus ID: 00:1f.3 chip ID: 8086:9d71
  Sound Server: ALSA v: k5.9.8-2-MANJARO
Network:
  Device-1: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter
  vendor: Bigfoot Networks Killer 1435 Wireless-AC driver: ath10k_pci v: kernel
  port: f040 bus ID: 02:00.0 chip ID: 168c:003e
  IF: wlp2s0 state: down mac: <filter>
  Device-2: Realtek RTL8153 Gigabit Ethernet Adapter type: USB driver: r8152
  bus ID: 2-1.2.1:5 chip ID: 0bda:8153
  IF: enp0s20f0u1u2u1 state: up speed: 1000 Mbps duplex: full mac: <filter>
Drives:
  Local Storage: total: 476.94 GiB used: 8.43 GiB (1.8%)
  ID-1: /dev/nvme0n1 vendor: Toshiba model: KXG50ZNV512G NVMe 512GB size: 476.94 GiB
  speed: 31.6 Gb/s lanes: 4 serial: <filter>
Partition:
  ID-1: / size: 451.54 GiB used: 8.43 GiB (1.9%) fs: ext4 dev: /dev/nvme0n1p2
Swap:
  ID-1: swap-1 type: partition size: 16.88 GiB used: 0 KiB (0.0%) priority: -2
  dev: /dev/nvme0n1p3
Sensors:
  System Temperatures: cpu: 33.0 C mobo: 26.0 C sodimm: 27.0 C
  Fan Speeds (RPM): cpu: 0
Info:
  Processes: 237 Uptime: 2m Memory: 15.34 GiB used: 1.21 GiB (7.9%) Init: systemd
  v: 246 Compilers: gcc: N/A Packages: pacman: 975 Shell: Bash v: 5.0.18
  running in: alacritty inxi: 3.1.08

And here is my sudo mhwd -li output:

> Installed PCI configs:
--------------------------------------------------------------------------------
                  NAME               VERSION          FREEDRIVER           TYPE
--------------------------------------------------------------------------------
           video-linux            2018.05.04                true            PCI


Warning: No installed USB configs!

And here is my lspci -v output:

e/DRAM Registers (rev 08)
	Subsystem: Dell Device 07e6
	Flags: bus master, fast devsel, latency 0
	Capabilities: <access denied>
	Kernel driver in use: skl_uncore

00:02.0 VGA compatible controller: Intel Corporation UHD Graphics 620 (rev 07) (prog-if 00 [VGA controller])
	DeviceName:  Onboard IGD
	Subsystem: Dell Device 07e6
	Flags: bus master, fast devsel, latency 0, IRQ 139
	Memory at db000000 (64-bit, non-prefetchable) [size=16M]
	Memory at 50000000 (64-bit, prefetchable) [size=256M]
	I/O ports at f000 [size=64]
	Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
	Capabilities: <access denied>
	Kernel driver in use: i915
	Kernel modules: i915

00:04.0 Signal processing controller: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem (rev 08)
	Subsystem: Dell Device 07e6
	Flags: fast devsel, IRQ 16
	Memory at dc420000 (64-bit, non-prefetchable) [size=32K]
	Capabilities: <access denied>
	Kernel driver in use: proc_thermal
	Kernel modules: processor_thermal_device

00:14.0 USB controller: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller (rev 21) (prog-if 30 [XHCI])
	Subsystem: Dell Device 07e6
	Flags: bus master, medium devsel, latency 0, IRQ 136
	Memory at dc410000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: <access denied>
	Kernel driver in use: xhci_hcd
	Kernel modules: xhci_pci

00:14.2 Signal processing controller: Intel Corporation Sunrise Point-LP Thermal subsystem (rev 21)
	Subsystem: Dell Device 07e6
	Flags: fast devsel, IRQ 18
	Memory at dc434000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>
	Kernel driver in use: intel_pch_thermal
	Kernel modules: intel_pch_thermal

00:15.0 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #0 (rev 21)
	Subsystem: Dell Device 07e6
	Flags: bus master, fast devsel, latency 0, IRQ 16
	Memory at dc433000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>
	Kernel driver in use: intel-lpss
	Kernel modules: intel_lpss_pci

00:15.1 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #1 (rev 21)
	Subsystem: Dell Device 07e6
	Flags: bus master, fast devsel, latency 0, IRQ 17
	Memory at dc432000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>
	Kernel driver in use: intel-lpss
	Kernel modules: intel_lpss_pci

00:16.0 Communication controller: Intel Corporation Sunrise Point-LP CSME HECI #1 (rev 21)
	Subsystem: Dell Device 07e6
	Flags: bus master, fast devsel, latency 0, IRQ 137
	Memory at dc431000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>
	Kernel driver in use: mei_me
	Kernel modules: mei_me

00:1c.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #1 (rev f1) (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 122
	Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
	I/O behind bridge: [disabled]
	Memory behind bridge: dc300000-dc3fffff [size=1M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

00:1c.2 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #3 (rev f1) (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 123
	Bus: primary=00, secondary=02, subordinate=02, sec-latency=0
	I/O behind bridge: [disabled]
	Memory behind bridge: dc000000-dc1fffff [size=2M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

00:1c.4 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #5 (rev f1) (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 124
	Bus: primary=00, secondary=03, subordinate=6d, sec-latency=0
	I/O behind bridge: 00002000-00002fff [size=4K]
	Memory behind bridge: ac000000-da0fffff [size=737M]
	Prefetchable memory behind bridge: 0000000060000000-00000000a9ffffff [size=1184M]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

00:1d.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #9 (rev f1) (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 125
	Bus: primary=00, secondary=6e, subordinate=6e, sec-latency=0
	I/O behind bridge: [disabled]
	Memory behind bridge: dc200000-dc2fffff [size=1M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

00:1f.0 ISA bridge: Intel Corporation Sunrise Point LPC Controller/eSPI Controller (rev 21)
	Subsystem: Dell Device 07e6
	Flags: bus master, fast devsel, latency 0

00:1f.2 Memory controller: Intel Corporation Sunrise Point-LP PMC (rev 21)
	Subsystem: Dell Device 07e6
	Flags: fast devsel
	Memory at dc42c000 (32-bit, non-prefetchable) [disabled] [size=16K]

00:1f.3 Audio device: Intel Corporation Sunrise Point-LP HD Audio (rev 21) (prog-if 80)
	Subsystem: Dell Device 07e6
	Flags: bus master, fast devsel, latency 32, IRQ 140
	Memory at dc428000 (64-bit, non-prefetchable) [size=16K]
	Memory at dc400000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: <access denied>
	Kernel driver in use: snd_hda_intel
	Kernel modules: snd_hda_intel, snd_soc_skl

00:1f.4 SMBus: Intel Corporation Sunrise Point-LP SMBus (rev 21)
	Subsystem: Dell Device 07e6
	Flags: medium devsel, IRQ 16
	Memory at dc430000 (64-bit, non-prefetchable) [size=256]
	I/O ports at f040 [size=32]
	Kernel driver in use: i801_smbus
	Kernel modules: i2c_i801

01:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS525A PCI Express Card Reader (rev 01)
	Subsystem: Dell Device 07e6
	Flags: bus master, fast devsel, latency 0, IRQ 135
	Memory at dc300000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>
	Kernel driver in use: rtsx_pci
	Kernel modules: rtsx_pci

02:00.0 Network controller: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter (rev 32)
	Subsystem: Bigfoot Networks, Inc. Killer 1435 Wireless-AC
	Flags: bus master, fast devsel, latency 0, IRQ 138
	Memory at dc000000 (64-bit, non-prefetchable) [size=2M]
	Capabilities: <access denied>
	Kernel driver in use: ath10k_pci
	Kernel modules: ath10k_pci

6e:00.0 Non-Volatile memory controller: Toshiba Corporation Device 0116 (prog-if 02 [NVM Express])
	Subsystem: Toshiba Corporation Device 0001
	Flags: bus master, fast devsel, latency 0, IRQ 16, NUMA node 0
	Memory at dc200000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: nvme

And here is my ls /sys/class/backlight output:

intel-backlight

Hope this information will be of any help! Currently, the only fix (for now) is simply going back to 5.8.18-1. Having both 5.8.18-1 and 5.9.8-2 installed keeps the same problem.

If you need even more information, I’ll happily oblige!

Just updated to Kernel 5.9.10-1 and I also can’t adjust screen brightness anymore. Indicator is showing and moving when trying to do so using keys, but brightness won’t adjust. Same goes for trying via tray icon slider. Screen turns black when I set brightness to 0%, though.

System:    Kernel: 5.9.10-1-MANJARO x86_64 bits: 64 compiler: gcc v: 10.2.0 
           Desktop: KDE Plasma 5.20.3 tk: Qt 5.15.1 wm: kwin_x11 dm: SDDM Distro: Manjaro Linux 
Machine:   Type: Laptop System: Dell product: XPS 15 7590 v: N/A serial: <filter> Chassis: 
           type: 10 serial: <filter> 
           Mobo: Dell model: 0VYV0G v: A00 serial: <filter> UEFI: Dell v: 1.7.0 date: 05/11/2020 
Battery:   ID-1: BAT0 charge: 80.0 Wh condition: 84.5/97.0 Wh (87%) volts: 12.1/11.4 
           model: SMP DELL GPM0365 serial: <filter> status: Discharging 
           Device-1: hidpp_battery_0 model: Logitech Wireless Mouse serial: <filter> 
           charge: 55% (should be ignored) status: Discharging 
CPU:       Info: 6-Core model: Intel Core i7-9750H bits: 64 type: MT MCP arch: Kaby Lake rev: A 
           L2 cache: 12.0 MiB 
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 62431 
           Speed: 873 MHz min/max: 800/4500 MHz Core speeds (MHz): 1: 873 2: 888 3: 878 4: 876 
           5: 884 6: 889 7: 874 8: 878 9: 881 10: 871 11: 882 12: 892 
Graphics:  Device-1: Intel UHD Graphics 630 vendor: Dell driver: i915 v: kernel bus ID: 00:02.0 
           chip ID: 8086:3e9b 
           Device-2: NVIDIA TU117M [GeForce GTX 1650 Mobile / Max-Q] vendor: Hewlett-Packard 
           driver: nvidia v: 450.80.02 bus ID: 01:00.0 chip ID: 10de:1f91 
           Device-3: Microdia Integrated_Webcam_HD type: USB driver: uvcvideo bus ID: 1-12:5 
           chip ID: 0c45:6723 
           Display: x11 server: X.Org 1.20.9 compositor: kwin_x11 driver: modesetting,nvidia 
           alternate: fbdev,intel,nouveau,nv,vesa resolution: 1920x1080 s-dpi: 96 
           OpenGL: renderer: Mesa Intel UHD Graphics 630 (CFL GT2) v: 4.6 Mesa 20.2.2 
           direct render: Yes 
Audio:     Device-1: Intel Cannon Lake PCH cAVS vendor: Dell driver: snd_hda_intel v: kernel 
           bus ID: 00:1f.3 chip ID: 8086:a348 
           Sound Server: ALSA v: k5.9.10-1-MANJARO 
Network:   Device-1: Intel Wi-Fi 6 AX200 vendor: Bigfoot Networks driver: iwlwifi v: kernel 
           port: 3000 bus ID: 3b:00.0 chip ID: 8086:2723 
           IF: wlp59s0 state: up mac: <filter> 
Drives:    Local Storage: total: 476.94 GiB used: 263.42 GiB (55.2%) 
           ID-1: /dev/nvme0n1 vendor: Toshiba model: KXG60ZNV512G NVMe 512GB size: 476.94 GiB 
           speed: 31.6 Gb/s lanes: 4 serial: <filter> 
Partition: ID-1: / size: 451.64 GiB used: 263.42 GiB (58.3%) fs: ext4 dev: /dev/nvme0n1p2 
Swap:      ID-1: swap-1 type: partition size: 16.79 GiB used: 0 KiB (0.0%) priority: -2 
           dev: /dev/nvme0n1p3 
Sensors:   System Temperatures: cpu: 36.0 C mobo: N/A 
           Fan Speeds (RPM): cpu: 0 fan-2: 0 
Info:      Processes: 294 Uptime: 22m Memory: 15.26 GiB used: 1.92 GiB (12.6%) Init: systemd 
           v: 246 Compilers: gcc: 10.2.0 Packages: pacman: 1364 Shell: Bash v: 5.0.18 
           running in: konsole inxi: 3.1.08

Just checked it myself and my laptop does the exact same thing when setting it to 0%. Does your laptop also boots with 100% brightness when you have it plugged in? And about ~20% when running on battery?

Same problem on T480 with KDE on 5.9.10-1, booting up 5.4 solved the issue for now.

So I had put my problem into this thread: [Stable Update] 2020-11-22 - Kernels, Pamac, Gnome, Jade, OnlyOffice, Xorg-Server

And it was split by @Yochanan into a new thread: Screen brightness issues

In this new thread a solution was offered that did work for me!

Hopefully this fix will work for others as well! Many thanks to @Jack1221 :smile: !

[EDIT] And yes, this solution works for the 5.9.10-1 kernel.

I have the same problem, but none of the solutions presented above helped.

The following did help

´´´
In the file /etc/default/grub change
GRUB_CMDLINE_LINUX=“acpi_osi=Linux acpi_backlight=vendor”
to
GRUB_CMDLINE_LINUX=“acpi_osi=Linux acpi_backlight=0”
´´´

I tried to make it more readable with 3 backticks, but I have no idea what a backtick is and where I would find it on my Belgian azerty keyboard.

@mbbs1024 here: `

Or you can just select the text and press Ctrl+Shift+C or the </> (preformatted text) icon.

Thanks for the tip on formatting.

For Lenovo Y540 (using Manjaro KDE) I’ve managed to fix it.

I’ve edited /etc/default/grub file to look like this

GRUB_CMDLINE_LINUX_DEFAULT="quiet apparmor=1 security=apparmor udev.log_priority=3 acpi_backlight=vendor"
GRUB_CMDLINE_LINUX="reboot=acpi"

I’ve also edited /usr/share/X11/xorg.conf.d/10-amdgpu-nvidia-drm-outputclass.conf by adding this line to the Nvidia OutputClass section

Option "RegistryDwords" "EnableBrightnessControl=1;"

Working file looks like this

Section "ServerLayout"
    Identifier "layout"
    Option "AllowNVIDIAGPUScreens"
EndSection

Section "OutputClass"
    Identifier "AMDgpu"
    MatchDriver "amdgpu"
    Driver "amdgpu"
EndSection

Section "OutputClass"
    Identifier "nvidia"
    MatchDriver "nvidia-drm"
    Driver "nvidia"
    Option "AllowEmptyInitialConfiguration"
    ModulePath "/usr/lib/nvidia/xorg"
    ModulePath "/usr/lib/xorg/modules"
    Option "RegistryDwords" "EnableBrightnessControl=1;"
EndSection

Alternative way:

I’m currently using the optimus-switch-sddm tool to switch between GPU’s and on Nvidia driver, my /etc/default/grub file looks like

GRUB_CMDLINE_LINUX_DEFAULT="quiet apparmor=1 security=apparmor udev.log_priority=3"
GRUB_CMDLINE_LINUX="reboot=acpi"

it was also working with

GRUB_CMDLINE_LINUX_DEFAULT="quiet apparmor=1 security=apparmor udev.log_priority=3 i915.enable_dpcd_backlight=0"
GRUB_CMDLINE_LINUX="reboot=acpi"

and I also added

Option "RegistryDwords" "EnableBrightnessControl=1;"

to the /usr/share/X11/xorg.conf.d/10-amdgpu-nvidia-drm-outputclass.conf to the the Nvidia OutputClass section as above.

Additional info

After some updates /usr/share/X11/xorg.conf.d/10-amdgpu-nvidia-drm-outputclass.conf was overwritten so I had to edit it again.

Don’t forget to run it after editing the grub file

sudo update-grub
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I had the very same problem BUT in my case loading kernel 5.7 instead of 5.9 fixed the issue for some time. Today there was an update that removed kernel 5.7, so the problem was back for me since 5.8 and 5.9 kernels both have the issue, I’ve tried to install and load the latest kernel 5.10 and the problem is fixed for me…

Dude, I don’t understand how you works…
You create the link “nvidia_0” or you always have it???
for me, I don’t have “nvidia_0”, and my “mhwd --listinstalled” looks not good.
I have no idea how to fix this problem, but I think yours are the most closed solution, could you list more detail?

Means you do not have the nVidia drivers installed or you don’t have an nVidia card.

Start here:

https://wiki.manjaro.org/index.php/Configure_Graphics_Cards

and if that doesn’t help, open a new topic and provide more information:

and post some more information so we can see what’s really going on. Now we know the symptom of the disease, but we need some more probing to know where the origin lies…

An inxi --admin --verbosity=7 --filter --no-host --width would be the minimum required information… (Personally Identifiable Information like serial numbers and MAC addresses will be filtered out by the above command)

:+1:

Hi,

I’ve done the first modifications you sugested on the grub file and now my system won’t boot !

I havent do “sudo update-grub” that you recommended at the end, because I’ve only see it after doing the modifications and as the screen brightness was still no changing, I tried to reboot.

Do you how can repair my boot ?

Heeey, it’s working !

I didn’t manage to repair my boot and had to reinstall the system after my last BIG MISTAKE, but now it’s ok : )

For me (Lenovo 5 15ARH05H), it worked with :

GRUB_CMDLINE_LINUX_DEFAULT=“quiet apparmor=1 security=apparmor udev.log_priority=3 acpi_backlight=vendor”
GRUB_CMDLINE_LINUX=“reboot=acpi”

AND

the line in the /usr/share/X11/xorg.conf.d/10-amdgpu-nvidia-drm-outputclass.conf file

But, it didn’t work with :

GRUB_CMDLINE_LINUX="i915.enable_dpcd_backlight=0"

My BIG MISTAKE was to not do :

sudo update-grub

So, please don’t forget to do it.

Everything was working but…

When I tried to install proprietary drivers my system stop booting again and I have to reinstall all again, as all my attempts of repairing Grub were again unfruitful.

There are 4 drivers listed in my “display controller” on the “Hardware Configuration” :

  • video-nvidia
  • video-linux
  • video modesetting
  • video-vesa

Only the first one was in proprietary and the latter three were in Open Source. When I tried to changed them to proprietary the system didn’t boot anymore.

Now I’m in 5.10.15-1 kernel and the screen brightness regulation is working, but I honestly don’t know if this is due to the editions suggested by @kuba kuba or due to the new kernel.

Anyway, now it’s working and I’m tired of having to reinstall the whole OS each time I try to make an improvement in the system so I’m not touching it anymore.

My drivers are in Open Source which are supposed to be worse, and they will remain like that until it’s clear to me that it’s safe to try to change them.

Quite disappointed of Manjaro if you ask me, but it’s the way it is.

Well, I updated to Kernel 5.10 now but on my computer (XFCE,NVIDIA,HP), brightness regulation still doesn’t work. And I couldn’t follow your settings above and what you changed. Could you condense it maybe?

Condense…

I did :

And SPECIALLY :

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I’m putting this here in case someone else has a laptop like mine, a Dell Latitude E7470 and like me has this same problem while running kernel 5.9.16-1. Upgrading to 5.10.19-1 has fixed this problem and I can now make my screen dim or bright on demand.
I’m new to Manjaro (about a week now) and this feature of switching kernels is a real boon. My only concern that making this change has maybe broken something else, only time will tell :slightly_smiling_face:

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