[HP WMI] Issues with brightness keys [HP ProBook 640 G1]

[Ian Turner]

Three of the "function" keys on this laptop don't work at all: "Mute", "Brightness Down", and "Brightness Up". I believe these keys are controlled by WMI. Other buttons not controlled by WMI, such as "Volume Up" and "Volume Down" (both by ACPI), work fine. Setting display brightness via software (e.g., GUI slider) works fine.

Sometimes other keys (Windows, up/down arrow, pgup/pgdn) are interpreted as "Brightness Down". This behavior seems to come and go randomly after each reboot.

I have tried setting (separately) acpi_osi=Linux and acpi_backlight=vendor without effect.

The hp_wmi driver raises these message at each boot:
[ 19.610528] hp_wmi: query 0xd returned error 0x5
[ 19.610569] input: HP WMI hotkeys as /devices/virtual/input/input14

This system has the latest BIOS (1.43A, released 2018-01-25) and the latest Intel ME firmware (9.1.42.3002, released 2017-12-19).

No output is generated when pressing these buttons with evtest (choosing option 8, "HP WMI hotkeys"), xev, or acpi_listen).

I have attached the debugging information requested at <https://wiki.ubuntu.com/Kernel/Debugging/Backlight#Debugging_information_to_provide_in_your_bug_report>, although fwts method does not seem to be a valid command (anymore?).

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-12-generic 4.15.0-12.13
ProcVersionSignature: Ubuntu 4.15.0-12.13-generic 4.15.7
Uname: Linux 4.15.0-12-generic x86_64
ApportVersion: 2.20.8-0ubuntu10
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: vectro 1415 F.... pulseaudio
 /dev/snd/controlC0: vectro 1415 F.... pulseaudio
CurrentDesktop: KDE
Date: Fri Mar 23 17:15:19 2018
HibernationDevice: RESUME=UUID=0f34a9a4-0160-489a-9325-45913b03eb06
InstallationDate: Installed on 2018-03-23 (0 days ago)
InstallationMedia: Kubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20180306.1)
MachineType: Hewlett-Packard HP ProBook 640 G1
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-12-generic root=/dev/mapper/internal-root ro quiet splash acpi_osi=Linux vt.handoff=1
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-12-generic N/A
 linux-backports-modules-4.15.0-12-generic N/A
 linux-firmware 1.173
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 01/25/2018
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: L78 Ver. 01.43
dmi.board.name: 2101
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 16.3C
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvrL78Ver.01.43:bd01/25/2018:svnHewlett-Packard:pnHPProBook640G1:pvrA3009DD10303:rvnHewlett-Packard:rn2101:rvrKBCVersion16.3C:cvnHewlett-Packard:ct10:cvr:
dmi.product.family: 103C_5336AN G=N L=BUS B=HP S=PRO
dmi.product.name: HP ProBook 640 G1
dmi.product.version: A3009DD10303
dmi.sys.vendor: Hewlett-Packard

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Ian Turner (vectro)]

I think this bug may actually be INVALID.

It turns out the root cause is setting this in /etc/default/grub, which I had done in order to change the Grub keyboard layout:
GRUB_TERMINAL_INPUT=at_keyboard

After removing this line (and updating grub), the brightness keys work correctly and none of the other keys trigger brightness changes.

[Marcel Munce (mmunce)]

I also see those errors. Additionally "hp_wmi: query 0x4 returned error 0x5".
My grub configuration is untouched!