@Sulliwane did you find the solution? If yes can you please let me know. I am gettting the same issue in my Lenovo legion 5i.
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1881462 Title: Brightness settings don't work on Lenovo Ideapad 5 15ARE05 Status in linux package in Ubuntu: Confirmed Bug description: After installation, the notebook brighness buttons change brightness settings, but settings are not applied on the screen. In the log files I can see something like this: Failed to start Load/Save Screen Backlight Brightness of backlight:amdgpu_bl0. amdgpu_bl0: Failed to write system 'brightness' attribute: No such device or address amdgpu_bl0: Failed to write system 'brightness' attribute: No such device or address Failed to get backlight or LED device 'backlight:acpi_video0': No such device ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: xorg 1:7.7+19ubuntu14 ProcVersionSignature: Ubuntu 5.4.0-33.37-generic 5.4.34 Uname: Linux 5.4.0-33-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.2 Architecture: amd64 BootLog: Error: [Errno 13] Keine Berechtigung: '/var/log/boot.log' CasperMD5CheckResult: skip CompositorRunning: None CurrentDesktop: X-Cinnamon Date: Sun May 31 10:43:17 2020 DistUpgraded: Fresh install DistroCodename: focal DistroVariant: ubuntu ExtraDebuggingInterest: Yes GraphicsCard: Advanced Micro Devices, Inc. [AMD/ATI] Renoir [1002:1636] (rev ce) (prog-if 00 [VGA controller]) Subsystem: Lenovo Renoir [17aa:381b] InstallationDate: Installed on 2020-05-29 (1 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) MachineType: LENOVO 81YQ ProcEnviron: PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-33-generic root=UUID=94ab3768-11c5-4582-9374-578128353e38 ro quiet splash amdgpu.exp_hw_support=1 vt.handoff=7 SourcePackage: xorg Symptom: display UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 03/25/2020 dmi.bios.vendor: LENOVO dmi.bios.version: E7CN24WW dmi.board.asset.tag: No Asset Tag dmi.board.name: LNVNB161216 dmi.board.vendor: LENOVO dmi.board.version: No DPK dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: IdeaPad 5 15ARE05 dmi.modalias: dmi:bvnLENOVO:bvrE7CN24WW:bd03/25/2020:svnLENOVO:pn81YQ:pvrIdeaPad515ARE05:rvnLENOVO:rnLNVNB161216:rvrNoDPK:cvnLENOVO:ct10:cvrIdeaPad515ARE05: dmi.product.family: IdeaPad 5 15ARE05 dmi.product.name: 81YQ dmi.product.sku: LENOVO_MT_81YQ_BU_idea_FM_IdeaPad 5 15ARE05 dmi.product.version: IdeaPad 5 15ARE05 dmi.sys.vendor: LENOVO version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.101-2 version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.4-2ubuntu1 version.libgl1-mesa-glx: libgl1-mesa-glx N/A version.xserver-xorg-core: xserver-xorg-core 2:1.20.8-2ubuntu2 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1881462/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp