Changing the grub line GRUB_CMDLINE_LINUX_DEFAULT=""
to GRUB_CMDLINE_LINUX_DEFAULT="acpi_backlight=vendor" did not work. -- 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/1667323 Title: Backlight control does not work and there are no entries in /sys/class/backlight Status in linux package in Ubuntu: Confirmed Bug description: It was working fine until today. The folder /sys/class/backlight/ use to have "acpi_video0/brightness", but now is empty. I am using Nvidia Proprietary driver 340.101 (proprietary, tested). The problem persists even with the 304 driver. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.4.0-64-generic 4.4.0-64.85 ProcVersionSignature: Ubuntu 4.4.0-64.85-generic 4.4.44 Uname: Linux 4.4.0-64-generic x86_64 NonfreeKernelModules: nvidia_uvm nvidia ApportVersion: 2.20.1-0ubuntu2.5 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: desgua 2028 F.... pulseaudio /dev/snd/controlC0: desgua 2028 F.... pulseaudio CurrentDesktop: Unity Date: Thu Feb 23 11:31:18 2017 HibernationDevice: RESUME=UUID=f23a6347-9483-460e-aa29-cbc47850f890 InstallationDate: Installed on 2014-05-01 (1028 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) Lsusb: Bus 002 Device 003: ID 064e:a127 Suyin Corp. Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub MachineType: Hewlett-Packard HP Pavilion dv6 Notebook PC ProcFB: ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-64-generic root=/dev/mapper/ubuntu--vg-root ro RelatedPackageVersions: linux-restricted-modules-4.4.0-64-generic N/A linux-backports-modules-4.4.0-64-generic N/A linux-firmware 1.157.8 SourcePackage: linux UpgradeStatus: Upgraded to xenial on 2016-08-17 (189 days ago) dmi.bios.date: 12/03/2009 dmi.bios.vendor: Hewlett-Packard dmi.bios.version: F.13 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: 3659 dmi.board.vendor: Hewlett-Packard dmi.board.version: 32.23 dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.chassis.version: N/A dmi.modalias: dmi:bvnHewlett-Packard:bvrF.13:bd12/03/2009:svnHewlett-Packard:pnHPPaviliondv6NotebookPC:pvr049D210000241210000020000:rvnHewlett-Packard:rn3659:rvr32.23:cvnHewlett-Packard:ct10:cvrN/A: dmi.product.name: HP Pavilion dv6 Notebook PC dmi.product.version: 049D210000241210000020000 dmi.sys.vendor: Hewlett-Packard To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1667323/+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