Brightness keys don't work on HP Elitebook Folio 1040 G1

Bug Description

The brightness keys (F9, F10) don't work on HP Elitebook Folio 1040 G1. The keyboard backlight key at F11 works fine though.

Known workaround (2014年04月06日): Use "acpi_backlight=vendor"/3.13.x+ series kernel use: "video.use_native_backlight=1 as a boot option.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-23-generic 3.13.0-23.45 [modified: boot/vmlinuz-3.13.0-23-generic]
ProcVersionSignature: Ubuntu 3.13.0-23.45-generic 3.13.8
Uname: Linux 3.13.0-23-generic x86_64
ApportVersion: 2.14.1-0ubuntu1
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: jpds 3933 F.... pulseaudio
/dev/snd/controlC0: jpds 3933 F.... pulseaudio
CurrentDesktop: Unity
Date: Sun Apr 6 18:37:24 2014
HibernationDevice: RESUME=UUID=05490d4c-6800-46a1-b5ba-8b32bdc57e89
InstallationDate: Installed on 2014年04月06日 (0 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Daily amd64 (20140406)
MachineType: Hewlett-Packard HP EliteBook Folio 1040 G1
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.13.0-23-generic.efi.signed root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=7
RelatedPackageVersions:
linux-restricted-modules-3.13.0-23-generic N/A
linux-backports-modules-3.13.0-23-generic N/A
linux-firmware 1.127
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/09/2014
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: L83 Ver. 01.05
dmi.board.name: 213E
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 24.2A
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvrL83Ver.01.05:bd02/09/2014:svnHewlett-Packard:pnHPEliteBookFolio1040G1:pvrA3009DD18303:rvnHewlett-Packard:rn213E:rvrKBCVersion24.2A:cvnHewlett-Packard:ct10:cvr:
dmi.product.name: HP EliteBook Folio 1040 G1
dmi.product.version: A3009DD18303
dmi.sys.vendor: Hewlett-Packard

This change was made by a bot.

Collected above per: https://wiki.ubuntu.com/Kernel/Debugging/Backlight

Using acpi_backlight=vendor as a boot option makes the function keys work.

Executing:

# echo 8 > /sys/class/backlight/intel_backlight/brightness

...makes the screen VERY dark but still slightly viewable.

Removed kernel option "acpi_backlight=vendor" and added: "video.use_bios_initial_backlight=0".

System is unable to change brightness at all (hotkeys or a brightness applet) - though this is a EFI system.

Using 3.13.x+ series kernel, rebooted with just kernel parameter "video.use_native_backlight=1" → brightness can be changed with both methods.

Ok I have identified a possible fix, one which adds a quirk table, and obliquely references models similar to yours. Could you test this kernel and report back here:

http://people.canonical.com/~apw/lp1303419-trusty/

Above kernel fixes the issue for me.

This bug was fixed in the package linux - 3.13.0-24.46

---------------
linux (3.13.0-24.46) trusty; urgency=low

[ Andy Whitcroft ]

* [Config] d-i -- add nvme devices to block-modules udeb
- LP: #1303710

[ Paolo Pisati ]

* [Config] build vexpress a9 dtb
- LP: #1303657
* [Config] disable HVC_DCC
- LP: #1303657

[ Tim Gardner ]

* Release Tracking Bug
- LP: #1305158
* rebase to v3.13.9
* CONFIG_RTLBTCOEXIST=m
- LP: #1296591

[ Upstream Kernel Changes ]

* HID: Bluetooth: hidp: make sure input buffers are big enough
- LP: #1252874
* ACPI / video: Add systems that should favour native backlight interface
- LP: #1303419
* rds: prevent dereference of a NULL device in rds_iw_laddr_check
- LP: #1302222
- CVE-2014-2678
* x86/efi: Fix 32-bit fallout
- LP: #1301590
* drm/nouveau/devinit: tidy up the subdev class definition
- LP: #1158689
* drm/nouveau/device: provide a way for devinit to mark engines as
disabled
- LP: #1158689
* drm/nv50-/devinit: prevent use of engines marked as disabled by
hw/vbios
- LP: #1158689
* rtlwifi: btcoexist: Add new mini driver
- LP: #1296591
* rtlwifi: Prepare existing drivers for new driver
- LP: #1296591
* rtlwifi: add MSI interrupts mode support
- LP: #1296591
* rtlwifi: rtl8188ee: enable MSI interrupts mode
- LP: #1296591

[ Upstream Kernel Changes ]

* rebase to v3.13.9
-- Tim Gardner <email address hidden> 2014年4月04日 09:26:27 -0400