apport information ** Tags added: apport-collected resolute wayland-session
** Description changed: On my Lenovo ThinkPad L13 Yoga Gen 2a (model 21AES01A00), the keyboard backlight is not detected on Linux kernel 7.x. The keyboard backlight works correctly on kernels 6.8 and 6.9 (e.g., Linux Mint), where /sys/class/leds/tpacpi::kbd_backlight is present. On kernel 7.x, the LED interface is missing entirely. Expected behavior: thinkpad_acpi should detect the keyboard backlight and expose the LED interface tpacpi::kbd_backlight. Actual behavior: The keyboard backlight is not detected. The Fn+Space key does nothing. There is no LED entry for the keyboard backlight under /sys/class/leds/. thinkpad_acpi prints the following messages when loading: thinkpad_acpi: This ThinkPad has standard ACPI backlight brightness control, supported by the ACPI video driver thinkpad_acpi: Standard ACPI backlight interface available, not loading native one This is incorrect: The ThinkPad L13 Yoga Gen 2a does have a native ThinkPad keyboard backlight, and it works on older kernels. Hardware: Lenovo ThinkPad L13 Yoga Gen 2a Model: 21AES01A00 BIOS: R1QET52W (1.38) EC: R1QHT32W Kernel version: 7.0.0-15-generic (Ubuntu 26.04) Relevant dmesg output: [ 15.265890] thinkpad_acpi: This ThinkPad has standard ACPI backlight brightness control, supported by the ACPI video driver [ 15.265892] thinkpad_acpi: Disabling thinkpad-acpi brightness events by default... [ 373.695843] thinkpad_acpi: Standard ACPI backlight interface available, not loading native one + --- + ProblemType: Bug + ApportVersion: 2.34.0-0ubuntu2 + Architecture: amd64 + CasperMD5CheckResult: pass + CurrentDesktop: ubuntu:GNOME + DistroRelease: Ubuntu 26.04 + InstallationDate: Installed on 2026-02-06 (103 days ago) + InstallationMedia: Ubuntu 24.04.3 LTS "Noble Numbat" - Release amd64 (20250805.1) + MachineType: LENOVO 21AES01A00 + Package: linux (not installed) + ProcEnviron: + LANG=de_DE.UTF-8 + PATH=(custom, no user) + SHELL=/bin/bash + TERM=xterm-256color + XDG_RUNTIME_DIR=<set> + ProcFB: 0 amdgpudrmfb + ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-15-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash amdgpu.runpm=0 amdgpu.gpu_recovery=1 pcie_aspm=off pci=noaer crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M + ProcVersionSignature: Ubuntu 7.0.0-15.15-generic 7.0.0 + Tags: resolute wayland-session + Uname: Linux 7.0.0-15-generic x86_64 + UpgradeStatus: Upgraded to resolute on 2026-05-16 (4 days ago) + UserGroups: adm cdrom dialout dip kvm libvirt lpadmin plugdev sudo users + _MarkForUpload: True + dmi.bios.date: 10/09/2025 + dmi.bios.release: 1.38 + dmi.bios.vendor: LENOVO + dmi.bios.version: R1QET52W (1.38 ) + dmi.board.asset.tag: Not Available + dmi.board.name: 21AES01A00 + dmi.board.vendor: LENOVO + dmi.board.version: Not Defined + dmi.chassis.asset.tag: No Asset Information + dmi.chassis.type: 31 + dmi.chassis.vendor: LENOVO + dmi.chassis.version: None + dmi.ec.firmware.release: 1.18 + dmi.modalias: dmi:bvnLENOVO:bvrR1QET52W(1.38):bd10/09/2025:br1.38:efr1.18:svnLENOVO:pn21AES01A00:pvrThinkPadL13YogaGen2a:rvnLENOVO:rn21AES01A00:rvrNotDefined:cvnLENOVO:ct31:cvrNone:skuLENOVO_MT_21AE_BU_Think_FM_ThinkPadL13YogaGen2a:pfaThinkPadL13YogaGen2a: + dmi.product.family: ThinkPad L13 Yoga Gen 2a + dmi.product.name: 21AES01A00 + dmi.product.sku: LENOVO_MT_21AE_BU_Think_FM_ThinkPad L13 Yoga Gen 2a + dmi.product.version: ThinkPad L13 Yoga Gen 2a + dmi.sys.vendor: LENOVO ** Attachment added: "AlsaInfo.txt" https://bugs.launchpad.net/bugs/2152818/+attachment/5972009/+files/AlsaInfo.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2152818 Title: ThinkPad L13 Yoga Gen 2a: Keyboard backlight not detected in kernel 7.x (thinkpad_acpi does not expose tpacpi::kbd_backlight) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2152818/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
