Hi, Thanks for your feedback. I had a chat with somebody with some experience and he suggested it should be fixed in userspace, here: https://git.gnome.org/browse/gnome-settings-daemon/tree/plugins/power/gsd-backlight-linux.c
This is what he suggests (if the above is indeed what Ubuntu uses, because it is meant for Fedora): In the gsd_backlight_helper_get_best_backlight helper. It only looks at the type of backlight and not at the connection between the backlight interface and the connector. An option is, if the gsd_backlight_helper_get_type (devices, "firmware") and gsd_backlight_helper_get_type (devices, "platform") calls both are unsuccessful, then instead of using gsd_backlight_helper_get_type which simply returns the first matching one of the found backlights of type raw, do the following: Take $PATH as the variable to /sys/class/backlight/foo dir and check the content of $PATH/../enabled, it has to be "enabled", that way you can find out which backlight interface is connected to an LVDS interface that actually has a connected LCD. If no interface is found with: `cat $PATH/../enabled` == "enabled" then as a fallback, still return the first found interface. I tried to implement this, but just getting the development environment setup to develop and test took me so much time that I haven't gotten to it. Perhaps the above is easy to implement for someone with the proper setup. Please keep us informed, if I make progress I will post too (but that might take a while). cheers -- 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/1683445 Title: E6430 brightness control not working Status in Linux: Confirmed Status in linux package in Ubuntu: Confirmed Bug description: The Dell E6430 with Nvidia Optimus enables in BIOS, using the Open Source Nouveau driver shows the brightness slider moving but does not affect the brightness. When using the kernel boot option acpi_backlight=vendor , the brightness control works. ProblemType: Bug DistroRelease: Ubuntu 17.04 Package: linux-image-4.10.0-19-generic 4.10.0-19.21 ProcVersionSignature: Ubuntu 4.10.0-19.21-generic 4.10.8 Uname: Linux 4.10.0-19-generic x86_64 NonfreeKernelModules: wl ApportVersion: 2.20.4-0ubuntu4 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: ubuntu 2081 F.... pulseaudio CurrentDesktop: Unity:Unity7 Date: Mon Apr 17 20:00:56 2017 HibernationDevice: RESUME=UUID=66528b53-0f42-4043-9ff8-da8f86036be6 InstallationDate: Installed on 2017-04-10 (7 days ago) InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Beta amd64 (20170321) MachineType: Dell Inc. Latitude E6430 ProcFB: 0 nouveaufb 1 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.10.0-19-generic.efi.signed root=UUID=4e08c33d-f8cf-4159-a559-a0463d67b96c ro quiet splash acpi_backlight=vendor vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-4.10.0-19-generic N/A linux-backports-modules-4.10.0-19-generic N/A linux-firmware 1.164 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 01/18/2016 dmi.bios.vendor: Dell Inc. dmi.bios.version: A18 dmi.board.name: 0H3MT5 dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 9 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvrA18:bd01/18/2016:svnDellInc.:pnLatitudeE6430:pvr01:rvnDellInc.:rn0H3MT5:rvrA00:cvnDellInc.:ct9:cvr: dmi.product.name: Latitude E6430 dmi.product.version: 01 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1683445/+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
