As per prev. comment, the test kernel re-enables the keyboard brightness setting. However, the slider in the Gnome panel menu is not being moved when using the keyboard keys. Dragging the slider with the mouse does change the brightness, though.
(May be related: The volume slider in the panel menu & the volume keys show the same behaviour: the volume keys work but do not affect the slider) And by the way, the brightness problem also occurs on Asus Zenbook Flip UX561UD, and the test kernel behaves in the same way, keys work but slider unaffected. -- 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/1858844 Title: [Dell XPS 15 9575] Screen brightness stopped working with linux- image-5.4.0-9-generic Status in linux package in Ubuntu: Confirmed Bug description: I upgraded to Focal Fossa 3 days ago and nothing broke. At the time, it was still using linux 5.3 (linux-image-5.3.0-24-generic). Today, it updated to linux 5.4 (linux-image-5.4.0-9-generic) and after rebooting, the screen brightness does not work anymore - neither from keyboard keys nor from the slider in the gnome-shell panel. It works again when rebooting into the previous linux- image-5.3.0-24-generic kernel. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-9-generic 5.4.0-9.12 ProcVersionSignature: Ubuntu 5.4.0-9.12-generic 5.4.3 Uname: Linux 5.4.0-9-generic x86_64 ApportVersion: 2.20.11-0ubuntu15 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: mario 1892 F.... pulseaudio CurrentDesktop: ubuntu:GNOME Date: Wed Jan 8 20:23:31 2020 InstallationDate: Installed on 2018-09-13 (481 days ago) InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Alpha amd64 (20180912) MachineType: Dell Inc. XPS 15 9575 ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-9-generic root=UUID=26ff4c95-5f68-4121-b7d0-989fa705fcc8 ro quiet splash RelatedPackageVersions: linux-restricted-modules-5.4.0-9-generic N/A linux-backports-modules-5.4.0-9-generic N/A linux-firmware 1.184 SourcePackage: linux UpgradeStatus: Upgraded to focal on 2020-01-04 (3 days ago) dmi.bios.date: 07/07/2019 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.7.1 dmi.board.name: 0C32VW dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 31 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.7.1:bd07/07/2019:svnDellInc.:pnXPS159575:pvr:rvnDellInc.:rn0C32VW:rvrA00:cvnDellInc.:ct31:cvr: dmi.product.family: XPS dmi.product.name: XPS 15 9575 dmi.product.sku: 080D dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1858844/+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
