Brightness keys (fn+f5/f6) not working, UX305FA

[Daniel]

Brightness keys does not change screen brightness. Manually editing the brightness in system settings does work however. Using xev, neither of the brightness function keys are detected.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: xorg 1:7.7+1ubuntu8.1
ProcVersionSignature: Ubuntu 3.19.0-26.28~14.04.1-generic 3.19.8-ckt4
Uname: Linux 3.19.0-26-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.14.1-0ubuntu3.12
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Fri Sep 4 08:59:14 2015
DistUpgraded: Fresh install
DistroCodename: trusty
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation Broadwell-U Integrated Graphics [8086:161e] (rev 08) (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Device [1043:181d]
InstallationDate: Installed on 2015-09-02 (1 days ago)
InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 003: ID 064e:9700 Suyin Corp.
 Bus 001 Device 002: ID 8087:0a2a Intel Corp.
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: ASUSTeK COMPUTER INC. UX305FA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-26-generic.efi.signed root=UUID=dc0d1e93-b3f9-4b94-9fd9-4c91317f91f7 ro quiet splash acpi_osi=Linux vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/19/2015
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: UX305FA.210
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: UX305FA
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK COMPUTER INC.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrUX305FA.210:bd05/19/2015:svnASUSTeKCOMPUTERINC.:pnUX305FA:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnUX305FA:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:
dmi.product.name: UX305FA
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.
version.compiz: compiz 1:0.9.11.3+14.04.20150313-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.60-2~ubuntu14.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri N/A
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core N/A
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati N/A
version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A
xserver.bootTime: Fri Sep 4 08:03:23 2015
xserver.configfile: /etc/X11/xorg.conf
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.17.1-0ubuntu3~trusty1
xserver.video_driver: intel

[penalvch (penalvch)]

Daniel, thank you for reporting this and helping make Ubuntu better. Could you please test the latest upstream kernel available from the very top line at the top of the page from http://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D (the release names are irrelevant for testing, and please do not test the daily folder)? Install instructions are available at https://wiki.ubuntu.com/Kernel/MainlineBuilds . This will allow additional upstream developers to examine the issue.

If the latest kernel did not allow you to test to the issue (ex. you couldn't boot into the OS) please make a comment in your report about this, and continue to test the next most recent kernel version until you can test to the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this issue is fixed in the mainline kernel, please add the following tags by clicking on the yellow circle with a black pencil icon, next to the word Tags, located at the bottom of the report description:
kernel-fixed-upstream
kernel-fixed-upstream-X.Y-rcZ

Where X, Y, and Z are numbers corresponding to the kernel version.

If the mainline kernel does not fix the issue, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-X.Y-rcZ

Please note, an error to install the kernel does not fit the criteria of kernel-bug-exists-upstream.

Once testing of the latest upstream kernel is complete, please mark this report's Status as Confirmed. Please let us know your results.

Thank you for your understanding.

[Daniel (daniel-lundn)]

The bug also exists when testing on upstream kernel v4.3-rc6-unstable.

[penalvch (penalvch)]

Daniel, anything change if you remove the non-default kernel boot parameter:
acpi_osi=Linux

If not, then could you please advise to the WORKAROUNDs noted in https://wiki.ubuntu.com/Kernel/Debugging/Backlight ?

Also, in order to upstream this, could you please test the latest mainline kernel (4.4) and advise to the results?

[Daniel (daniel-lundn)]

--- acpi_osi removed from kernel parameters in grub ---

Hotkeys still not working, brightness applet working.

By https://wiki.ubuntu.com/Kernel/Debugging/Backlight
I am in the following situation:
"Backlight control works through the brightness applet but not via hotkeys."

Thereafter following the link on debugging hotkeys https://wiki.ubuntu.com/Hotkeys/Troubleshooting

Results from step-by-step troubleshooting:
 - Nothing registered with xev when pressing fn+f5/f6 (backlight down/up)
 - Nothing registered with evtest when pressing fn+f5/f6
 - Nothing registered with acpi_listen when pressing fn+f5/f6 (other fn-key functions such as turning off the touchpad are registered)

Also, please find the files produced by commands under "Useful Information to Collect in Reports" attached.

--- WORKAROUND in https://wiki.ubuntu.com/Kernel/Debugging/Backlight ---

Booting with only acpi_backlight=vendor, adjusting the brightness through the applet stops working as well. The brightness changes when executing "echo 8 > /sys/class/backlight/intel_backlight/brightness".

Booting with only video.use_bios_initial_backlight=0, brightness applet works, but not the brightness hotkeys.

Booting with only acpi_osi=, neither applet nor hotkeys work.

Booting with only video.use_native_backlight=1, applet works but not hotkeys.

Also, please find vendorbacklight and lslabacklight files attached.

--- Kernel v4.5-rc4-wily ---

Problem still exists