> Did this issue start happening after an update/upgrade? Was there a prior kernel version where you were not having this particular problem?
I can not say if brightness controls worked immediately after installing the system. However, they were definitely broken after installing a few standard packages and the (proprietary) graphics drivers. The latest upstream kernel does *not* resolve the issue (neither are the FN buttons working, nor are `backlight` classes available under `/sys/class/backlight`). (I guess "generic" was the proper variant to test?) $ uname -r 4.15.0-041500-generic $ dmesg | grep acpi [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x01] high edge lint[0x1]) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x02] high edge lint[0x1]) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x03] high edge lint[0x1]) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x04] high edge lint[0x1]) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x05] high edge lint[0x1]) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x06] high edge lint[0x1]) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x07] high edge lint[0x1]) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x08] high edge lint[0x1]) [ 0.045039] acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5 [ 0.104918] acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig ASPM ClockPM Segments MSI] [ 0.105102] acpi PNP0A08:00: _OSC: platform does not support [PCIeHotplug PME AER PCIeCapability] [ 0.105105] acpi PNP0A08:00: _OSC: not requesting control; platform does not support [PCIeCapability] [ 0.105109] acpi PNP0A08:00: _OSC: OS requested [PCIeHotplug PME AER PCIeCapability] [ 0.105112] acpi PNP0A08:00: _OSC: platform willing to grant [] [ 0.105114] acpi PNP0A08:00: _OSC failed (AE_SUPPORT); disabling ASPM [ 0.264669] clocksource: acpi_pm: mask: 0xffffff max_cycles: 0xffffff, max_idle_ns: 2085701024 ns [ 1.541604] acpi device:77: hash matches [ 1.542026] acpi device:4a: hash matches [ 14.000879] acpi PNP0C14:02: duplicate WMI GUID 05901221-D566-11D1-B2F0-00A0C9062910 (first instance was on PNP0C14:01) [ 14.000963] acpi PNP0C14:03: duplicate WMI GUID 05901221-D566-11D1-B2F0-00A0C9062910 (first instance was on PNP0C14:01) [ 14.075152] thinkpad_acpi: ThinkPad ACPI Extras v0.25 [ 14.075153] thinkpad_acpi: http://ibm-acpi.sf.net/ [ 14.075154] thinkpad_acpi: ThinkPad BIOS N1UET37W (1.11 ), EC unknown [ 14.075155] thinkpad_acpi: Lenovo ThinkPad P51, model 20HJS27B00 [ 14.440734] thinkpad_acpi: radio switch found; radios are enabled [ 14.639622] thinkpad_acpi: rfkill switch tpacpi_bluetooth_sw: radio is unblocked [ 14.650775] input: ThinkPad Extra Buttons as /devices/platform/thinkpad_acpi/input/input13 ** Changed in: linux (Ubuntu) Status: Incomplete => Confirmed -- 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: Confirmed 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
