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

I’m having issues getting my screen brightness to change and would really appreciate any help. The Fn Keys and the brightness slider in the power manager system tray both appear like they’re working, in that the XFCE brightness pop-up is displayed and adjusted as expected and the values in the brightness file of /sys/class/backlight change, but the actual screen brightness seems stuck at 100%. When I first installed Manjaro some months ago the brightness keys worked (in a janky way: the brightness up worked but brightness down set brightness to 0/turned off the display), but either a kernel update or switching to proprietary NVIDIA drivers seem to have cut off the connection between my actual screen brightness and the brightness values I can manipulate, so I have been primarily using my windows install at night but want to get back to pure Manjaro.

I have tried manipulating my grub command-line options as per another forum post (can’t link), but that didn’t seem to help:
With no CMDLINE option, I have an acpi_video0 symlink in /sys/class/backlight, and it behaves as I described above (brightness file responding to FN Keys and the sytem tray slider from 0-100, screen brightness stuck at 100).
With GRUB_CMDLINE_LINUX="acpi_backlight=" none or native I get nothing in /sys/class/backlight, unresponsive brightness Fn Keys, and no slider in the system tray, and with the vendor option I get an ideapad symlink in /sys/class/backlight with a brightness file responsively changing from 0 to 16 but no actual screen brightness adjustment as with no CMDLINE option and the acpi_video0 brightness device, so I just went back to no grub CMDLINE option.

I have also tried switching to kernels 57 (same problem), and 59 (no boot), so I’ve gone back to 58.

I just recently found a workaround to change brightness manually by disabling redshift, executing xrandr --output DP-4 --brightness $value and then re-enabling redshift (if I don’t disable redshift it seems to reset the brightness value after a slight delay), but this is a little cumbersome and I’m wondering if there’s a better way to get the gui and laptop key brightness adjustment methods working.

In case they help diagnose my problem, here are my inxi -Fxxz:

System:    Kernel: 5.8.6-1-MANJARO x86_64 bits: 64 compiler: N/A Desktop: Xfce 4.14.2 tk: Gtk 3.24.20 wm: xfwm4 dm: LightDM 
           Distro: Manjaro Linux 
Machine:   Type: Laptop System: LENOVO product: 81SY v: Legion Y540-15IRH-PG0 serial: <filter> Chassis: type: 10 
           v: Legion Y540-15IRH-PG0 serial: <filter> 
           Mobo: LENOVO model: LNVNB161216 v: SDK0R32862 WIN serial: <filter> UEFI: LENOVO v: BHCN35WW date: 11/23/2019 
Battery:   ID-1: BAT0 charge: 31.5 Wh condition: 53.4/52.5 Wh (102%) volts: 11.6/11.3 model: LGC L17L3PG1 serial: <filter> 
           status: Unknown 
CPU:       Topology: 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: 800 MHz min/max: 800/4500 MHz Core speeds (MHz): 1: 800 2: 800 3: 800 4: 800 5: 800 6: 800 7: 800 8: 800 
           9: 800 10: 800 11: 800 12: 800 
Graphics:  Device-1: NVIDIA TU117M [GeForce GTX 1650 Mobile / Max-Q] vendor: Lenovo driver: nvidia v: 440.100 bus ID: 01:00.0 
           chip ID: 10de:1f91 
           Device-2: Lite-On Integrated Camera type: USB driver: uvcvideo bus ID: 1-6:3 chip ID: 04ca:7070 
           Display: x11 server: X.Org 1.20.8 driver: nvidia resolution: 1920x1080~60Hz s-dpi: 96 
           OpenGL: renderer: GeForce GTX 1650/PCIe/SSE2 v: 4.6.0 NVIDIA 440.100 direct render: Yes 
Audio:     Device-1: Intel Cannon Lake PCH cAVS vendor: Lenovo driver: snd_hda_intel v: kernel bus ID: 00:1f.3 
           chip ID: 8086:a348 
           Device-2: NVIDIA vendor: Lenovo driver: snd_hda_intel v: kernel bus ID: 01:00.1 chip ID: 10de:10fa 
           Sound Server: ALSA v: k5.8.6-1-MANJARO 
Network:   Device-1: Intel Wireless-AC 9560 [Jefferson Peak] driver: iwlwifi v: kernel bus ID: 00:14.3 chip ID: 8086:a370 
           IF: wlp0s20f3 state: up mac: <filter> 
           Device-2: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet vendor: Lenovo driver: r8169 v: kernel port: 3000 
           bus ID: 07:00.0 chip ID: 10ec:8168 
           IF: enp7s0 state: down mac: <filter> 
Drives:    Local Storage: total: 1.38 TiB used: 27.79 GiB (2.0%) 
           ID-1: /dev/nvme0n1 vendor: Samsung model: MZVLB512HBJQ-000L2 size: 476.94 GiB speed: 31.6 Gb/s lanes: 4 
           serial: <filter> 
           ID-2: /dev/sda vendor: Seagate model: ST1000LM049-2GH172 size: 931.51 GiB speed: 6.0 Gb/s serial: <filter> 
Partition: ID-1: / size: 95.13 GiB used: 14.30 GiB (15.0%) fs: ext4 dev: /dev/nvme0n1p6 
           ID-2: /home size: 406.44 GiB used: 13.49 GiB (3.3%) fs: ext4 dev: /dev/sda4 
Swap:      ID-1: swap-1 type: partition size: 7.45 GiB used: 0 KiB (0.0%) priority: -2 dev: /dev/sda3 
Sensors:   System Temperatures: cpu: 55.0 C mobo: N/A gpu: nvidia temp: 48 C 
           Fan Speeds (RPM): N/A 
Info:      Processes: 305 Uptime: 47m Memory: 15.56 GiB used: 2.97 GiB (19.1%) Init: systemd v: 246 Compilers: gcc: 10.2.0 
           Packages: pacman: 1136 Shell: Bash v: 5.0.18 running in: xfce4-terminal inxi: 3.1.05 

the contents of /etc/X11/mhwd.d:

==> mhwd.d/nvidia.conf <==
# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 440.82

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "Files"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
	Option "NoLogo" "1"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Extensions"
    Option         "COMPOSITE" "Enable"
EndSection

 
Section "InputClass"
    Identifier          "Keyboard Defaults"
    MatchIsKeyboard        "yes"
    Option              "XkbOptions" "terminate:ctrl_alt_bksp"
EndSection
 

==> mhwd.d/nvidia.conf.nvidia-xconfig-original <==

and finally /etc/X11/xorg.conf.d:

==> xorg.conf.d/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" "us"
        Option "XkbModel" "pc105"
EndSection

==> xorg.conf.d/90-mhwd.conf <==
# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 440.82

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "Files"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
	Option "NoLogo" "1"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Extensions"
    Option         "COMPOSITE" "Enable"
EndSection

 
Section "InputClass"
    Identifier          "Keyboard Defaults"
    MatchIsKeyboard        "yes"
    Option              "XkbOptions" "terminate:ctrl_alt_bksp"
EndSection
 

If anyone has any suggestions/ideas they would be much appreciated.

2 Likes

Do I see that correctly that your laptop does not have an integrated gpu? I find that nigh unbelievable. Could you please run sudo mhwd -li and lspci -v and post the output?

1 Like

You’re right, it does have an iGPU, but in my BIOS boot menu there is an option to select between discrete graphics and switchable graphics, and for now I just have discrete graphics selected.

for sudo mhwd -li:

> Installed PCI configs:
--------------------------------------------------------------------------------
                  NAME               VERSION          FREEDRIVER           TYPE
--------------------------------------------------------------------------------
    video-nvidia-440xx            2019.10.25               false            PCI


Warning: No installed USB configs!

I think the no USB config could be related to a Possibly missing firmware for module: xhci_pci warning I get when the kernel builds with mkinitcpio? Not sure if it’s related to this issue, however.

lspci -v:

00:00.0 Host bridge: Intel Corporation 8th Gen Core Processor Host Bridge/DRAM Registers (rev 07)
	Subsystem: Lenovo Device 3807
	Flags: bus master, fast devsel, latency 0
	Capabilities: [e0] Vendor Specific Information: Len=10 <?>
	Kernel driver in use: skl_uncore

00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor PCIe Controller (x16) (rev 07) (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 121
	Bus: primary=00, secondary=01, subordinate=05, sec-latency=0
	I/O behind bridge: 00004000-00004fff [size=4K]
	Memory behind bridge: b2000000-b30fffff [size=17M]
	Prefetchable memory behind bridge: 00000000a0000000-00000000b1ffffff [size=288M]
	Capabilities: [88] Subsystem: Lenovo Device 3812
	Capabilities: [80] Power Management version 3
	Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
	Capabilities: [a0] Express Root Port (Slot+), MSI 00
	Capabilities: [100] Virtual Channel
	Capabilities: [140] Root Complex Link
	Capabilities: [d94] Secondary PCI Express
	Kernel driver in use: pcieport

00:04.0 Signal processing controller: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem (rev 07)
	Subsystem: Lenovo Device 382f
	Flags: bus master, fast devsel, latency 0, IRQ 16
	Memory at b3410000 (64-bit, non-prefetchable) [size=32K]
	Capabilities: [90] MSI: Enable- Count=1/1 Maskable- 64bit-
	Capabilities: [d0] Power Management version 3
	Capabilities: [e0] Vendor Specific Information: Len=0c <?>
	Kernel driver in use: proc_thermal
	Kernel modules: processor_thermal_device

00:08.0 System peripheral: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model
	Subsystem: Lenovo Device 3864
	Flags: bus master, fast devsel, latency 0, IRQ 255
	Memory at b3424000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: [90] MSI: Enable- Count=1/1 Maskable- 64bit-
	Capabilities: [dc] Power Management version 2
	Capabilities: [f0] PCI Advanced Features

00:12.0 Signal processing controller: Intel Corporation Cannon Lake PCH Thermal Controller (rev 10)
	Subsystem: Lenovo Device 3802
	Flags: bus master, fast devsel, latency 0, IRQ 16
	Memory at b3425000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: [50] Power Management version 3
	Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
	Kernel driver in use: intel_pch_thermal
	Kernel modules: intel_pch_thermal

00:14.0 USB controller: Intel Corporation Cannon Lake PCH USB 3.1 xHCI Host Controller (rev 10) (prog-if 30 [XHCI])
	Subsystem: Lenovo Device 3806
	Flags: bus master, medium devsel, latency 0, IRQ 138
	Memory at b3400000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: [70] Power Management version 2
	Capabilities: [80] MSI: Enable+ Count=1/8 Maskable- 64bit+
	Capabilities: [90] Vendor Specific Information: Len=14 <?>
	Kernel driver in use: xhci_hcd
	Kernel modules: xhci_pci

00:14.2 RAM memory: Intel Corporation Cannon Lake PCH Shared SRAM (rev 10)
	Subsystem: Lenovo Device 3824
	Flags: bus master, fast devsel, latency 0
	Memory at b3420000 (64-bit, non-prefetchable) [size=8K]
	Memory at b3426000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: [80] Power Management version 3

00:14.3 Network controller: Intel Corporation Wireless-AC 9560 [Jefferson Peak] (rev 10)
	Subsystem: Intel Corporation Device 0034
	Flags: bus master, fast devsel, latency 0, IRQ 16
	Memory at b3418000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: [c8] Power Management version 3
	Capabilities: [d0] MSI: Enable- Count=1/1 Maskable- 64bit+
	Capabilities: [40] Express Root Complex Integrated Endpoint, MSI 00
	Capabilities: [80] MSI-X: Enable+ Count=16 Masked-
	Capabilities: [100] Null
	Capabilities: [14c] Latency Tolerance Reporting
	Capabilities: [164] Vendor Specific Information: ID=0010 Rev=0 Len=014 <?>
	Kernel driver in use: iwlwifi
	Kernel modules: iwlwifi

00:15.0 Serial bus controller [0c80]: Intel Corporation Cannon Lake PCH Serial IO I2C Controller #0 (rev 10)
	Subsystem: Lenovo Device 3803
	Flags: bus master, fast devsel, latency 0, IRQ 16
	Memory at b3427000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: [80] Power Management version 3
	Capabilities: [90] Vendor Specific Information: Len=14 <?>
	Kernel driver in use: intel-lpss
	Kernel modules: intel_lpss_pci

00:15.1 Serial bus controller [0c80]: Intel Corporation Cannon Lake PCH Serial IO I2C Controller #1 (rev 10)
	Subsystem: Lenovo Device 3804
	Flags: bus master, fast devsel, latency 0, IRQ 17
	Memory at b3428000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: [80] Power Management version 3
	Capabilities: [90] Vendor Specific Information: Len=14 <?>
	Kernel driver in use: intel-lpss
	Kernel modules: intel_lpss_pci

00:16.0 Communication controller: Intel Corporation Cannon Lake PCH HECI Controller (rev 10)
	Subsystem: Lenovo Device 3810
	Flags: bus master, fast devsel, latency 0, IRQ 139
	Memory at b3429000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: [50] Power Management version 3
	Capabilities: [8c] MSI: Enable+ Count=1/1 Maskable- 64bit+
	Capabilities: [a4] Vendor Specific Information: Len=14 <?>
	Kernel driver in use: mei_me
	Kernel modules: mei_me

00:17.0 SATA controller: Intel Corporation Cannon Lake Mobile PCH SATA AHCI Controller (rev 10) (prog-if 01 [AHCI 1.0])
	Subsystem: Lenovo Device 3808
	Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 124
	Memory at b3422000 (32-bit, non-prefetchable) [size=8K]
	Memory at b342e000 (32-bit, non-prefetchable) [size=256]
	I/O ports at 5040 [size=8]
	I/O ports at 5048 [size=4]
	I/O ports at 5020 [size=32]
	Memory at b342d000 (32-bit, non-prefetchable) [size=2K]
	Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
	Capabilities: [70] Power Management version 3
	Capabilities: [a8] SATA HBA v1.0
	Kernel driver in use: ahci

00:1d.0 PCI bridge: Intel Corporation Cannon Lake PCH PCI Express Root Port #9 (rev f0) (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 122
	Bus: primary=00, secondary=06, subordinate=06, sec-latency=0
	I/O behind bridge: [disabled]
	Memory behind bridge: b3300000-b33fffff [size=1M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: [40] Express Root Port (Slot+), MSI 00
	Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
	Capabilities: [90] Subsystem: Lenovo Device 381e
	Capabilities: [a0] Power Management version 3
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Access Control Services
	Capabilities: [150] Precision Time Measurement
	Capabilities: [200] L1 PM Substates
	Capabilities: [220] Secondary PCI Express
	Capabilities: [250] Downstream Port Containment
	Kernel driver in use: pcieport

00:1d.5 PCI bridge: Intel Corporation Cannon Lake PCH PCI Express Root Port #14 (rev f0) (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 123
	Bus: primary=00, secondary=07, subordinate=07, sec-latency=0
	I/O behind bridge: 00003000-00003fff [size=4K]
	Memory behind bridge: b3200000-b32fffff [size=1M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: [40] Express Root Port (Slot+), MSI 00
	Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
	Capabilities: [90] Subsystem: Lenovo Device 3823
	Capabilities: [a0] Power Management version 3
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Access Control Services
	Capabilities: [150] Precision Time Measurement
	Capabilities: [200] L1 PM Substates
	Capabilities: [220] Secondary PCI Express
	Capabilities: [250] Downstream Port Containment
	Kernel driver in use: pcieport

00:1e.0 Communication controller: Intel Corporation Cannon Lake PCH Serial IO UART Host Controller (rev 10)
	Subsystem: Lenovo Device 3813
	Flags: bus master, fast devsel, latency 0, IRQ 20
	Memory at b342a000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: [80] Power Management version 3
	Capabilities: [90] Vendor Specific Information: Len=14 <?>
	Kernel driver in use: intel-lpss
	Kernel modules: intel_lpss_pci

00:1f.0 ISA bridge: Intel Corporation HM470 Chipset LPC/eSPI Controller (rev 10)
	Subsystem: Lenovo Device 380e
	Flags: bus master, medium devsel, latency 0

00:1f.3 Audio device: Intel Corporation Cannon Lake PCH cAVS (rev 10)
	Subsystem: Lenovo Device 380f
	Flags: bus master, fast devsel, latency 32, IRQ 155
	Memory at b341c000 (64-bit, non-prefetchable) [size=16K]
	Memory at b3100000 (64-bit, non-prefetchable) [size=1M]
	Capabilities: [50] Power Management version 3
	Capabilities: [80] Vendor Specific Information: Len=14 <?>
	Capabilities: [60] MSI: Enable+ Count=1/1 Maskable- 64bit+
	Kernel driver in use: snd_hda_intel
	Kernel modules: snd_hda_intel, snd_soc_skl, snd_sof_pci

00:1f.4 SMBus: Intel Corporation Cannon Lake PCH SMBus Controller (rev 10)
	Subsystem: Lenovo Device 3814
	Flags: medium devsel, IRQ 16
	Memory at b342b000 (64-bit, non-prefetchable) [size=256]
	I/O ports at 5000 [size=32]
	Kernel driver in use: i801_smbus
	Kernel modules: i2c_i801

00:1f.5 Serial bus controller [0c80]: Intel Corporation Cannon Lake PCH SPI Controller (rev 10)
	Subsystem: Lenovo Device 3827
	Flags: bus master, fast devsel, latency 0
	Memory at fe010000 (32-bit, non-prefetchable) [size=4K]
	Kernel driver in use: intel-spi
	Kernel modules: intel_spi_pci

01:00.0 VGA compatible controller: NVIDIA Corporation TU117M [GeForce GTX 1650 Mobile / Max-Q] (rev a1) (prog-if 00 [VGA controller])
	Subsystem: Lenovo Device 3ffb
	Flags: bus master, fast devsel, latency 0, IRQ 156
	Memory at b2000000 (32-bit, non-prefetchable) [size=16M]
	Memory at a0000000 (64-bit, prefetchable) [size=256M]
	Memory at b0000000 (64-bit, prefetchable) [size=32M]
	I/O ports at 4000 [size=128]
	Expansion ROM at b3080000 [virtual] [disabled] [size=512K]
	Capabilities: [60] Power Management version 3
	Capabilities: [68] MSI: Enable+ Count=1/1 Maskable- 64bit+
	Capabilities: [78] Express Legacy Endpoint, MSI 00
	Capabilities: [100] Virtual Channel
	Capabilities: [250] Latency Tolerance Reporting
	Capabilities: [258] L1 PM Substates
	Capabilities: [128] Power Budgeting <?>
	Capabilities: [420] Advanced Error Reporting
	Capabilities: [600] Vendor Specific Information: ID=0001 Rev=1 Len=024 <?>
	Capabilities: [900] Secondary PCI Express
	Capabilities: [bb0] Physical Resizable BAR
	Kernel driver in use: nvidia
	Kernel modules: nouveau, nvidia_drm, nvidia

01:00.1 Audio device: NVIDIA Corporation Device 10fa (rev a1)
	Subsystem: Lenovo Device 3ffb
	Flags: bus master, fast devsel, latency 0, IRQ 17
	Memory at b3000000 (32-bit, non-prefetchable) [size=16K]
	Capabilities: [60] Power Management version 3
	Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+
	Capabilities: [78] Express Endpoint, MSI 00
	Capabilities: [100] Advanced Error Reporting
	Kernel driver in use: snd_hda_intel
	Kernel modules: snd_hda_intel

06:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983 (prog-if 02 [NVM Express])
	Subsystem: Samsung Electronics Co Ltd Device a801
	Flags: bus master, fast devsel, latency 0, IRQ 16, NUMA node 0
	Memory at b3300000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: [40] Power Management version 3
	Capabilities: [50] MSI: Enable- Count=1/32 Maskable- 64bit+
	Capabilities: [70] Express Endpoint, MSI 00
	Capabilities: [b0] MSI-X: Enable+ Count=33 Masked-
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [148] Device Serial Number 00-00-00-00-00-00-00-00
	Capabilities: [158] Power Budgeting <?>
	Capabilities: [168] Secondary PCI Express
	Capabilities: [188] Latency Tolerance Reporting
	Capabilities: [190] L1 PM Substates
	Kernel driver in use: nvme

07:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
	Subsystem: Lenovo Device 38cd
	Flags: bus master, fast devsel, latency 0, IRQ 17
	I/O ports at 3000 [size=256]
	Memory at b3204000 (64-bit, non-prefetchable) [size=4K]
	Memory at b3200000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: [40] Power Management version 3
	Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
	Capabilities: [70] Express Endpoint, MSI 01
	Capabilities: [b0] MSI-X: Enable+ Count=4 Masked-
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Virtual Channel
	Capabilities: [160] Device Serial Number 01-00-00-00-68-4c-e0-00
	Capabilities: [170] Latency Tolerance Reporting
	Capabilities: [178] L1 PM Substates
	Kernel driver in use: r8169
	Kernel modules: r8169
  1. I have this section:

    Section "Extensions"
        Option         "COMPOSITE" "Enable"
    EndSection
    

    in my /etc/X11/mhwd.d/nvidia.conf as well.

  2. What’s the output of:

    ls /sys/class/backlight
    

:question:

  1. That section is in there for me too, I think. It’s the second to last section

  2. In /sys/class/backlight there is a symlink to this acpi_video0 folder at /sys/devices/pci0000\:00/0000\:00\:01.0/0000\:01\:00.0/backlight/acpi_video0/, the contents of which are:

acpi_video0/actual_brightness:100
acpi_video0/bl_power:0
acpi_video0/brightness:100
grep: acpi_video0/device: Is a directory
acpi_video0/max_brightness:100
grep: acpi_video0/power: Is a directory
acpi_video0/scale:unknown
grep: acpi_video0/subsystem: Is a directory
acpi_video0/type:firmware

As I was meaning to say earlier, the value in the /sys/class/backlight/acpi_video0/brightness file (and the actual_brightness file) will change when I change my brightness via function keys or the sys tray slider, but my screen stays at 100% brightness. And I have a similar ideapad folder linked there after rebooting with the acpi_backlight=vendor Grub command-line option, with similar problems.

I have:

ls /sys/class/backlight/
nvidia_0

and it works!

What is:

mhwd --listinstalled
> Installed PCI configs:
--------------------------------------------------------------------------------
                  NAME               VERSION          FREEDRIVER           TYPE
--------------------------------------------------------------------------------
    video-nvidia-440xx            2019.10.25               false            PCI

(included my output to speed things up.)

:innocent:

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
1 Like

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: