I can reproduce this bug on my ThinkPad p51, this is a new bug in 18.10. Any progress?
** Changed in: linux (Ubuntu) Status: Expired => New -- 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/1747273 Title: Can not control brightness on Thinkpad P51 Status in linux package in Ubuntu: New Bug description: I can not modify the screen brightness in Ubuntu 17.10. Controls aside, the classes in `proc` are either not available or non- functional depending on what arguments I provide in GRUB_CMDLINE_LINUX_DEFAULT. On a parallel installation (Ubuntu 16.04.3), brightness control works flawlessly. System Information ------------------ $ lsb_release -rd Description: Ubuntu 17.10 Release: 17.10 $ lspci 00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v6/7th Gen Core Processor Host Bridge/DRAM Registers (rev 05) 00:01.0 PCI bridge: Intel Corporation Skylake PCIe Controller (x16) (rev 05) 00:08.0 System peripheral: Intel Corporation Skylake Gaussian Mixture Model 00:14.0 USB controller: Intel Corporation Sunrise Point-H USB 3.0 xHCI Controller (rev 31) 00:14.2 Signal processing controller: Intel Corporation Sunrise Point-H Thermal subsystem (rev 31) 00:15.0 Signal processing controller: Intel Corporation Sunrise Point-H Serial IO I2C Controller #0 (rev 31) 00:16.0 Communication controller: Intel Corporation Sunrise Point-H CSME HECI #1 (rev 31) 00:17.0 SATA controller: Intel Corporation Sunrise Point-H SATA controller [AHCI mode] (rev 31) 00:1b.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Root Port #17 (rev f1) 00:1c.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #1 (rev f1) 00:1c.2 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #3 (rev f1) 00:1c.4 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #5 (rev f1) 00:1d.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #9 (rev f1) 00:1d.4 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #13 (rev f1) 00:1f.0 ISA bridge: Intel Corporation Sunrise Point-H LPC Controller (rev 31) 00:1f.2 Memory controller: Intel Corporation Sunrise Point-H PMC (rev 31) 00:1f.3 Audio device: Intel Corporation Device a171 (rev 31) 00:1f.4 SMBus: Intel Corporation Sunrise Point-H SMBus (rev 31) 00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (5) I219-V (rev 31) 01:00.0 VGA compatible controller: NVIDIA Corporation GM107GLM [Quadro M1200 Mobile] (rev a2) 01:00.1 Audio device: NVIDIA Corporation Device 0fbc (rev a1) 02:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM961/PM961 04:00.0 Network controller: Intel Corporation Wireless 8265 / 8275 (rev 78) 3e:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM961/PM961 # with GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi=Linux thinkpad-acpi.brightness_enable=1": $ grep . -R /sys/class/backlight/thinkpad_screen/* /sys/class/backlight/thinkpad_screen/actual_brightness:0 /sys/class/backlight/thinkpad_screen/bl_power:0 /sys/class/backlight/thinkpad_screen/brightness:11 /sys/class/backlight/thinkpad_screen/max_brightness:15 /sys/class/backlight/thinkpad_screen/power/runtime_active_kids:0 /sys/class/backlight/thinkpad_screen/power/runtime_suspended_time:0 grep: /sys/class/backlight/thinkpad_screen/power/autosuspend_delay_ms: Input/output error /sys/class/backlight/thinkpad_screen/power/runtime_enabled:disabled /sys/class/backlight/thinkpad_screen/power/runtime_active_time:0 /sys/class/backlight/thinkpad_screen/power/control:auto /sys/class/backlight/thinkpad_screen/power/async:disabled /sys/class/backlight/thinkpad_screen/power/runtime_usage:0 /sys/class/backlight/thinkpad_screen/power/runtime_status:unsupported grep: warning: /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/subsystem: recursive directory loop /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/power/runtime_active_kids:0 /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/power/runtime_suspended_time:0 grep: /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/power/autosuspend_delay_ms: Input/output error /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/power/runtime_enabled:disabled /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/power/runtime_active_time:0 /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/power/control:auto /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/power/async:disabled /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/power/runtime_usage:0 /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/power/runtime_status:unsupported /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/max_brightness:15 /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/type:platform /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/brightness:11 /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/bl_power:0 /sys/class/backlight/thinkpad_screen/subsystem/thinkpad_screen/actual_brightness:0 /sys/class/backlight/thinkpad_screen/type:platform 3f:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS525A PCI Express Card Reader (rev 01) --- ApportVersion: 2.20.7-0ubuntu3.7 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: mhoff 2207 F.... pulseaudio /dev/snd/pcmC0D0p: mhoff 2207 F...m pulseaudio /dev/snd/controlC0: mhoff 2207 F.... pulseaudio /dev/snd/controlC2: mhoff 2207 F.... pulseaudio CurrentDesktop: ubuntu:GNOME DistroRelease: Ubuntu 17.10 HibernationDevice: RESUME=UUID=5d843303-18a4-4466-b711-98668a4d1172 InstallationDate: Installed on 2017-11-11 (86 days ago) InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20171018) MachineType: LENOVO 20HJS27B00 NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia Package: linux (not installed) ProcFB: 0 EFI VGA ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.13.0-32-generic.efi.signed root=/dev/mapper/ubuntu--vg-root ro acpi_osi=Linux thinkpad-acpi.brightness_enable=1 ProcVersionSignature: Ubuntu 4.13.0-32.35-generic 4.13.13 RelatedPackageVersions: linux-restricted-modules-4.13.0-32-generic N/A linux-backports-modules-4.13.0-32-generic N/A linux-firmware 1.169.2 Tags: artful Uname: Linux 4.13.0-32-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip disk libvirt lpadmin plugdev sambashare sudo _MarkForUpload: True dmi.bios.date: 07/24/2017 dmi.bios.vendor: LENOVO dmi.bios.version: N1UET37W (1.11 ) dmi.board.asset.tag: Not Available dmi.board.name: 20HJS27B00 dmi.board.vendor: LENOVO dmi.board.version: Not Defined dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.modalias: dmi:bvnLENOVO:bvrN1UET37W(1.11):bd07/24/2017:svnLENOVO:pn20HJS27B00:pvrThinkPadP51:rvnLENOVO:rn20HJS27B00:rvrNotDefined:cvnLENOVO:ct10:cvrNone: dmi.product.family: ThinkPad P51 dmi.product.name: 20HJS27B00 dmi.product.version: ThinkPad P51 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1747273/+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