2

So, like many other users, I can't set the brightness of my laptop using Fn keys or the brightness controls on settings.

I have tried all the solutions that I could fine but nothing happens.

  • Updating grub config with different options for acpi_backlight
    doesn't work

  • I've tried to change in the BIOS the option of Graphic device to
    switchable graphics but I ended up with a black screen during boot
    up.

  • Using xrandr --output DP_2 --brightness 0.8 allows to change the
    "brightness" but that actually only affects the gamma.

  • Using xbacklight -set 50 has no effect either

  • Changing the value of brightness directly in /sys/class/backlight/acpi_video0/brightness, /sys/class/backlight/actual_brightness or /sys/class/backlight/max_brightness doesn't work.

I've also been taking a look at the arch wiki (backlight) and found something strange.

The wiki says:

The brightness of the screen backlight is adjusted by setting the power level of the backlight LEDs or cathodes. The power level can often be controlled using the ACPI kernel module for video. An interface to this module is provided via a sysfs directory at /sys/class/backlight/.

The name of the directory depends on the graphics card model.

$ ls /sys/class/backlight/

acpi_video0

In this case, the backlight is managed by an ATI graphics card. In the case of an Intel card, the directory is called intel_backlight. In the following examples, acpi_video0 is used. If you use an Intel card, simply replace acpi_video0 with intel_backlight in the examples.

When I do ls /sys/class/backlight/ I get the directory acpi_video0 but according to my laptop specs (Lenovo Legion Y540) and the lshw command (see below) I have no ATI components. My graphics card is a Nvidia RTX 2060.

  1. What can I do to fix my brightness control issues?
  2. Is my distro (Pop_OS 19.10) not finding the hardware of my laptop correctly?
  3. Why do I get a black screen when setting Switchable graphics in the BIOS?

sudo lshw

lenovo-y540                 
description: Notebook
product: 81SX (LENOVO_MT_81SX_BU_idea_FM_Legion Y540-15IRH)
vendor: LENOVO
version: Legion Y540-15IRH
serial: PF14675L
width: 64 bits
capabilities: smbios-3.0.1 dmi-3.0.1 smp vsyscall32
configuration: administrator_password=disabled boot=normal chassis=notebook family=Legion Y540-15IRH frontpanel_password=disabled keyboard_password=disabled power-on_password=disabled sku=LENOVO_MT_81SX_BU_idea_FM_Legion Y540-15IRH uuid=98D5B7D7-C3C3-E911-80D8-98FA9BA0B3AE
  *-core
       description: Motherboard
       product: LNVNB161216
       vendor: LENOVO
       physical id: 0
       version: SDK0R32862 WIN
       serial: PF14675L
       slot: Type2 - Board Chassis Location
     *-firmware
          description: BIOS
          vendor: LENOVO
          physical id: 0
          version: BHCN29WW
          date: 06/19/2019
          size: 128KiB
          capacity: 10MiB
          capabilities: pci upgrade shadowing cdboot bootselect edd int13floppynec int13floppytoshiba int13floppy360 int13floppy1200 int13floppy720 int13floppy2880 int9keyboard int10video acpi usb biosbootspecification uefi
     *-cpu
          description: CPU
          product: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
          vendor: Intel Corp.
          physical id: 4
          bus info: cpu@0
          version: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
          serial: To Be Filled By O.E.M.
          slot: U3E1
          size: 2523MHz
          capacity: 4500MHz
          width: 64 bits
          clock: 100MHz
          capabilities: lm fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp x86-64 constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch cpuid_fault epb invpcid_single pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx rdseed adx smap clflushopt intel_pt xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp md_clear flush_l1d cpufreq
      configuration: cores=6 enabledcores=6 threads=12
        *-cache:0
             description: L1 cache
             physical id: 5
             slot: L1 Cache
             size: 384KiB
             capacity: 384KiB
             capabilities: synchronous internal write-back unified
             configuration: level=1
        *-cache:1
             description: L2 cache
             physical id: 6
             slot: L2 Cache
             size: 1536KiB
             capacity: 1536KiB
             capabilities: synchronous internal write-back unified
             configuration: level=2
        *-cache:2
             description: L3 cache
             physical id: 7
             slot: L3 Cache
             size: 12MiB
             capacity: 12MiB
             capabilities: synchronous internal write-back unified
             configuration: level=3
     *-memory
          description: System Memory
          physical id: 25
          slot: System board or motherboard
          size: 16GiB
        *-bank:0
             description: SODIMM DDR4 Synchronous 2667 MHz (0,4 ns)
             product: M471A1K43DB1-CTD
             vendor: Samsung
             physical id: 0
             serial: 335E0974
             slot: ChannelA-DIMM0
             size: 8GiB
             width: 64 bits
             clock: 2667MHz (0.4ns)
        *-bank:1
             description: SODIMM DDR4 Synchronous 2667 MHz (0,4 ns)
             product: M471A1K43DB1-CTD
             vendor: Samsung
             physical id: 1
             serial: 335E04AB
             slot: ChannelB-DIMM0
             size: 8GiB
             width: 64 bits
             clock: 2667MHz (0.4ns)
     *-pci
          description: Host bridge
          product: 8th Gen Core Processor Host Bridge/DRAM Registers
          vendor: Intel Corporation
          physical id: 100
          bus info: pci@0000:00:00.0
          version: 07
          width: 32 bits
          clock: 33MHz
          configuration: driver=skl_uncore
          resources: irq:0
        *-pci:0
             description: PCI bridge
             product: Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor PCIe Controller (x16)
             vendor: Intel Corporation
             physical id: 1
             bus info: pci@0000:00:01.0
             version: 07
             width: 32 bits
             clock: 33MHz
             capabilities: pci pm msi pciexpress normal_decode bus_master cap_list
             configuration: driver=pcieport
             resources: irq:121 ioport:4000(size=4096) memory:a0000000-b40fffff ioport:b4100000(size=1048576)
           *-display
                description: VGA compatible controller
                product: TU106M [GeForce RTX 2060 Mobile]
                vendor: NVIDIA Corporation
                physical id: 0
                bus info: pci@0000:01:00.0
                version: a1
                width: 64 bits
                clock: 33MHz
                capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
                configuration: driver=nvidia latency=0
                resources: irq:129 memory:b3000000-b3ffffff memory:a0000000-afffffff memory:b0000000-b1ffffff ioport:4000(size=128) memory:b2000000-b207ffff
           *-multimedia
                description: Audio device
                product: TU106 High Definition Audio Controller
                vendor: NVIDIA Corporation
                physical id: 0.1
                bus info: pci@0000:01:00.1
                version: a1
                width: 32 bits
                clock: 33MHz
                capabilities: pm msi pciexpress bus_master cap_list
                configuration: driver=snd_hda_intel latency=0
                resources: irq:17 memory:b4000000-b4003fff
           *-usb
                description: USB controller
                product: TU106 USB 3.1 Host Controller
                vendor: NVIDIA Corporation
                physical id: 0.2
                bus info: pci@0000:01:00.2
                version: a1
                width: 64 bits
                clock: 33MHz
                capabilities: msi pciexpress pm xhci cap_list
                configuration: driver=xhci_hcd latency=0
                resources: irq:125 memory:b4100000-b413ffff memory:b4140000-b414ffff
              *-usbhost:0
                   product: xHCI Host Controller
                   vendor: Linux 5.3.0-7648-generic xhci-hcd
                   physical id: 0
                   bus info: usb@3
                   logical name: usb3
                   version: 5.03
                   capabilities: usb-2.00
                   configuration: driver=hub slots=2 speed=480Mbit/s
              *-usbhost:1
                   product: xHCI Host Controller
                   vendor: Linux 5.3.0-7648-generic xhci-hcd
                   physical id: 1
                   bus info: usb@4
                   logical name: usb4
                   version: 5.03
                   capabilities: usb-3.10
                   configuration: driver=hub slots=4 speed=10000Mbit/s
           *-serial UNCLAIMED
                description: Serial bus controller
                product: TU106 USB Type-C Port Policy Controller
                vendor: NVIDIA Corporation
                physical id: 0.3
                bus info: pci@0000:01:00.3
                version: a1
                width: 32 bits
                clock: 33MHz
                capabilities: msi pciexpress pm cap_list
                configuration: latency=0
                resources: memory:b4004000-b4004fff
        *-generic:0
             description: Signal processing controller
             product: Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem
             vendor: Intel Corporation
             physical id: 4
             bus info: pci@0000:00:04.0
             version: 07
             width: 64 bits
             clock: 33MHz
             capabilities: msi pm bus_master cap_list
             configuration: driver=proc_thermal latency=0
             resources: irq:16 memory:b4510000-b4517fff
        *-generic:1 UNCLAIMED
             description: System peripheral
             product: Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th Gen Core Processor Gaussian Mixture Model
             vendor: Intel Corporation
             physical id: 8
             bus info: pci@0000:00:08.0
             version: 00
             width: 64 bits
             clock: 33MHz
             capabilities: msi pm bus_master cap_list
             configuration: latency=0
             resources: memory:b4524000-b4524fff
        *-generic:2
             description: Signal processing controller
             product: Cannon Lake PCH Thermal Controller
             vendor: Intel Corporation
             physical id: 12
             bus info: pci@0000:00:12.0
             version: 10
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi bus_master cap_list
             configuration: driver=intel_pch_thermal latency=0
             resources: irq:16 memory:b4525000-b4525fff
        *-usb
             description: USB controller
             product: Cannon Lake PCH USB 3.1 xHCI Host Controller
             vendor: Intel Corporation
             physical id: 14
             bus info: pci@0000:00:14.0
             version: 10
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi xhci bus_master cap_list
             configuration: driver=xhci_hcd latency=0
             resources: irq:124 memory:b4500000-b450ffff
           *-usbhost:0
                product: xHCI Host Controller
                vendor: Linux 5.3.0-7648-generic xhci-hcd
                physical id: 0
                bus info: usb@1
                logical name: usb1
                version: 5.03
                capabilities: usb-2.00
                configuration: driver=hub slots=16 speed=480Mbit/s
              *-usb:0
                   description: Generic USB device
                   product: iPhone
                   vendor: Apple Inc.
                   physical id: 2
                   bus info: usb@1:2
                   version: 8.01
                   serial: 237e4af9d8a88c3127e28e56dce2fea65bb7d1b4
                   capabilities: usb-2.00
                   configuration: driver=ipheth maxpower=500mA speed=480Mbit/s
              *-usb:1
                   description: Video
                   product: Integrated Camera
                   vendor: SunplusIT Inc
                   physical id: 6
                   bus info: usb@1:6
                   version: 54.23
                   capabilities: usb-2.01
                   configuration: driver=uvcvideo maxpower=500mA speed=480Mbit/s
              *-usb:2
                   description: Keyboard
                   product: ITE Device(8910)
                   vendor: ITE Tech. Inc.
                   physical id: 9
                   bus info: usb@1:9
                   version: 0.43
                   capabilities: usb-1.10
                   configuration: driver=usbhid maxpower=100mA speed=12Mbit/s
              *-usb:3
                   description: Bluetooth wireless interface
                   vendor: Intel Corp.
                   physical id: e
                   bus info: usb@1:e
                   version: 0.02
                   capabilities: bluetooth usb-2.00
                   configuration: driver=btusb maxpower=100mA speed=12Mbit/s
           *-usbhost:1
                product: xHCI Host Controller
                vendor: Linux 5.3.0-7648-generic xhci-hcd
                physical id: 1
                bus info: usb@2
                logical name: usb2
                version: 5.03
                capabilities: usb-3.10
                configuration: driver=hub slots=8 speed=10000Mbit/s
        *-memory UNCLAIMED
             description: RAM memory
             product: Cannon Lake PCH Shared SRAM
             vendor: Intel Corporation
             physical id: 14.2
             bus info: pci@0000:00:14.2
             version: 10
             width: 64 bits
             clock: 33MHz (30.3ns)
             capabilities: pm bus_master cap_list
             configuration: latency=0
             resources: memory:b4520000-b4521fff memory:b4526000-b4526fff
        *-network
             description: Wireless interface
             product: Wireless-AC 9560 [Jefferson Peak]
             vendor: Intel Corporation
             physical id: 14.3
             bus info: pci@0000:00:14.3
             logical name: wlp0s20f3
             version: 10
             serial: 50:e0:85:c6:2f:be
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wireless
             configuration: broadcast=yes driver=iwlwifi driverversion=5.3.0-7648-generic firmware=46.6bf1df06.0 ip=192.168.1.10 latency=0 link=yes multicast=yes wireless=IEEE 802.11
             resources: irq:16 memory:b4518000-b451bfff
        *-serial:0
             description: Serial bus controller
             product: Cannon Lake PCH Serial IO I2C Controller #0
             vendor: Intel Corporation
             physical id: 15
             bus info: pci@0000:00:15.0
             version: 10
             width: 64 bits
             clock: 33MHz
             capabilities: pm bus_master cap_list
             configuration: driver=intel-lpss latency=0
             resources: irq:16 memory:b4527000-b4527fff
        *-serial:1
             description: Serial bus controller
             product: Cannon Lake PCH Serial IO I2C Controller #1
             vendor: Intel Corporation
             physical id: 15.1
             bus info: pci@0000:00:15.1
             version: 10
             width: 64 bits
             clock: 33MHz
             capabilities: pm bus_master cap_list
             configuration: driver=intel-lpss latency=0
             resources: irq:17 memory:b4528000-b4528fff
        *-communication:0
             description: Communication controller
             product: Cannon Lake PCH HECI Controller
             vendor: Intel Corporation
             physical id: 16
             bus info: pci@0000:00:16.0
             version: 10
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi bus_master cap_list
             configuration: driver=mei_me latency=0
             resources: irq:142 memory:b4529000-b4529fff
        *-sata
             description: SATA controller
             product: Cannon Lake Mobile PCH SATA AHCI Controller
             vendor: Intel Corporation
             physical id: 17
             bus info: pci@0000:00:17.0
             version: 10
             width: 32 bits
             clock: 66MHz
             capabilities: sata msi pm ahci_1.0 bus_master cap_list
             configuration: driver=ahci latency=0
             resources: irq:126 memory:b4522000-b4523fff memory:b452e000-b452e0ff ioport:5040(size=8) ioport:5048(size=4) ioport:5020(size=32) memory:b452d000-b452d7ff
    *-pci:1
         description: PCI bridge
         product: Cannon Lake PCH PCI Express Root Port #9
         vendor: Intel Corporation
         physical id: 1d
         bus info: pci@0000:00:1d.0
         version: f0
         width: 32 bits
         clock: 33MHz
         capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
         configuration: driver=pcieport
         resources: irq:122 memory:b4400000-b44fffff
       *-storage
            description: Non-Volatile memory controller
            product: Micron Technology Inc
            vendor: Micron Technology Inc
            physical id: 0
            bus info: pci@0000:06:00.0
            version: 01
            width: 64 bits
            clock: 33MHz
            capabilities: storage pciexpress msix msi pm nvm_express bus_master cap_list
            configuration: driver=nvme latency=0
            resources: irq:16 memory:b4400000-b4403fff
    *-pci:2
         description: PCI bridge
         product: Cannon Lake PCH PCI Express Root Port #14
         vendor: Intel Corporation
         physical id: 1d.5
         bus info: pci@0000:00:1d.5
         version: f0
         width: 32 bits
         clock: 33MHz
         capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
         configuration: driver=pcieport
         resources: irq:123 ioport:3000(size=4096) memory:b4300000-b43fffff
       *-network
            description: Ethernet interface
            product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
            vendor: Realtek Semiconductor Co., Ltd.
            physical id: 0
            bus info: pci@0000:07:00.0
            logical name: enp7s0
            version: 15
            serial: 98:fa:9b:a0:b3:ae
            capacity: 1Gbit/s
            width: 64 bits
            clock: 33MHz
            capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
            configuration: autonegotiation=on broadcast=yes driver=r8169 firmware=rtl8168h-2_0.0.2 02/26/15 latency=0 link=no multicast=yes port=MII
            resources: irq:17 ioport:3000(size=256) memory:b4304000-b4304fff memory:b4300000-b4303fff
    *-communication:1
         description: Communication controller
         product: Intel Corporation
         vendor: Intel Corporation
         physical id: 1e
         bus info: pci@0000:00:1e.0
         version: 10
         width: 64 bits
         clock: 33MHz
         capabilities: pm bus_master cap_list
         configuration: driver=intel-lpss latency=0
         resources: irq:20 memory:b452a000-b452afff
    *-isa
         description: ISA bridge
         product: Intel Corporation
         vendor: Intel Corporation
         physical id: 1f
         bus info: pci@0000:00:1f.0
         version: 10
         width: 32 bits
         clock: 33MHz
         capabilities: isa bus_master
         configuration: latency=0
    *-multimedia
         description: Audio device
         product: Cannon Lake PCH cAVS
         vendor: Intel Corporation
         physical id: 1f.3
         bus info: pci@0000:00:1f.3
         version: 10
         width: 64 bits
         clock: 33MHz
         capabilities: pm msi bus_master cap_list
         configuration: driver=snd_hda_intel latency=32
         resources: irq:157 memory:b451c000-b451ffff memory:b4200000-b42fffff
    *-serial:2
         description: SMBus
         product: Cannon Lake PCH SMBus Controller
         vendor: Intel Corporation
         physical id: 1f.4
         bus info: pci@0000:00:1f.4
         version: 10
         width: 64 bits
         clock: 33MHz
         configuration: driver=i801_smbus latency=0
         resources: irq:16 memory:b452b000-b452b0ff ioport:5000(size=32)
    *-serial:3 UNCLAIMED
         description: Serial bus controller
         product: Cannon Lake PCH SPI Controller
         vendor: Intel Corporation
         physical id: 1f.5
         bus info: pci@0000:00:1f.5
         version: 10
         width: 32 bits
         clock: 33MHz
         capabilities: bus_master
         configuration: latency=0
         resources: memory:fe010000-fe010fff
 *-pnp00:00
      product: PnP device PNP0c02
      physical id: 1
      capabilities: pnp
      configuration: driver=system
 *-pnp00:01
      product: PnP device PNP0c02
      physical id: 2
      capabilities: pnp
      configuration: driver=system
 *-pnp00:02
      product: PnP device PNP0c02
      physical id: 3
      capabilities: pnp
      configuration: driver=system
 *-pnp00:03
      product: PnP device PNP0c02
      physical id: 5
      capabilities: pnp
      configuration: driver=system
 *-pnp00:04
      product: PnP device INT3f0d
      physical id: 6
      capabilities: pnp
      configuration: driver=system
 *-pnp00:05
      product: PnP device PNP0303
      physical id: 7
      capabilities: pnp
      configuration: driver=i8042 kbd
 *-pnp00:06
      product: PnP device PNP0c02
      physical id: 8
      capabilities: pnp
      configuration: driver=system
 *-pnp00:07
      product: PnP device PNP0c02
      physical id: 9
      capabilities: pnp
      configuration: driver=system
*-battery
   description: Zinc Air Battery
   product: CRB Battery 0
   vendor: -Virtual Battery 0-
   physical id: 1
   version: 08/08/2010
   serial: Battery 0
   slot: Fake
*-power UNCLAIMED
   description: OEM Define 1
   product: OEM Define 5
   vendor: OEM Define 2
   physical id: 2
   version: OEM Define 6
   serial: OEM Define 3
   capacity: 75mWh
*-network
   description: Ethernet interface
   physical id: 3
   bus info: usb@1:2
   logical name: enp0s20f0u2c4i2
   serial: 9e:f4:8e:80:a8:d1
   capabilities: ethernet physical
   configuration: broadcast=yes driver=ipheth link=no multicast=yes

1 Answer 1

0

Had the same problem with a Lenovo Legion 5, Manjaro, nvidia 1650. The solution was slightly different for me. It worked after installing the last nvidia driver available (video-nvidia-450xx), change the graphic option from Switchable graphics to Discrete in the UEFI / BIOS, and creating this file:

sudo nano /usr/share/X11/xorg.conf.d/10-nvidia-brightness.conf

with the following content:

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "Quadro K1000M" #this value had no effect for me
    Option         "RegistryDwords" "EnableBrightnessControl=1"
EndSection

Source: Brightness not working after installing NVIDIA driver

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