[Bug 2163244] Re: Ubuntu 26.04 LTS -- Lenovo Yoga 7 Pro 15IPH11 Screen Brightness not Working

RC4 attached here ** Attachment added: "brightness-rc4-vesa-drm.log" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2163244/+attachment/5991779/+files/brightness-rc4-vesa-drm.log -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2163244 Title: Ubuntu 26.04 LTS -- Lenovo Yoga 7 Pro 15IPH11 Screen Brightness not Working Status in linux package in Ubuntu: Confirmed Bug description: Laptop has OLED panel (EDO 3015 - EF25QBA63.B). Screen is at full brightness no matter how much I play with the slider. Tried the common internet tricks and scripts, nothing. Tried multiple flavours of Debian-based, Fedora-based and Arch based distros, problem persists. Tried kernel 7.0.0-22-generic, still nothing out of desperation I installed latest stable mainline kernel from kernel.ubuntu.com - v7.1.5-generic, problem still persists if VBT is required, please guide me to definitive steps as I tried one way I saw and it gives me an (input/output error) Ubuntu Release: 26.04 LTS Linux Release: 7.0.0-29-generic What is expected to happen: Moving screen brightness slider should modify the brightness of the OLED panel What happened instead: no response, screen at full brightness. demsg output does not print any responses as I play around with the slider. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-29-generic 7.0.0-29.29 ProcVersionSignature: Ubuntu 7.0.0-29.29-generic 7.0.12 Uname: Linux 7.0.0-29-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: omar 4317 F.... wireplumber /dev/snd/seq: omar 4311 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Tue Aug 11 15:15:58 2026 InstallationDate: Installed on 2026-08-11 (0 days ago) InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1) MachineType: LENOVO 83SN ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/bash XDG_RUNTIME_DIR=<set> ProcFB: 0 xedrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-29-generic root=UUID=02db4a59-6dd6-40bd-af90-92192c3afc49 ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 05/14/2026 dmi.bios.release: 1.37 dmi.bios.vendor: LENOVO dmi.bios.version: TNCN37WW dmi.board.asset.tag: NO Asset Tag dmi.board.name: LNVNB161216 dmi.board.vendor: LENOVO dmi.board.version: SDK0T76576 WIN dmi.chassis.asset.tag: NO Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Yoga Pro 7 15IPH11 dmi.ec.firmware.release: 1.37 dmi.modalias: dmi:bvnLENOVO:bvrTNCN37WW:bd05/14/2026:br1.37:efr1.37:svnLENOVO:pn83SN:pvrYogaPro715IPH11:rvnLENOVO:rnLNVNB161216:rvrSDK0T76576WIN:cvnLENOVO:ct10:cvrYogaPro715IPH11:skuLENOVO_MT_83SN_BU_idea_FM_YogaPro715IPH11:pfaYogaPro715IPH11: dmi.product.family: Yoga Pro 7 15IPH11 dmi.product.name: 83SN dmi.product.sku: LENOVO_MT_83SN_BU_idea_FM_Yoga Pro 7 15IPH11 dmi.product.version: Yoga Pro 7 15IPH11 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2163244/+subscriptions