Brightness fn keys don't work on dell xps 13 ultrabook

[Mitchell]

Have found this bug with the last few kernels in raring ringtail with my dell xps 13 ultrabook. Neither of the fn keys for brightness work... very frustrating! This seems to be a regression in the kernel, so I have marked this as an issue with the linux-header-kernel packages.

When I boot the computer I have this issue, as well as when the screen times out, or when I wake from suspend. The screen is stuck on 100% brightness. I have created a simple 'brightness-fix' script which I've put in /usr/local/bin, and run as root whenever I need to have the brightness less than 100%. I haven't looked to implment a better workaround, as I'm hoping for a more permanent fix from the kernel devs. My script for this is below:

---- code ----
#!/bin/bash

#FIx for brightness control:
echo 0 > /sys/class/backlight/intel_backlight/brightness
---- end code ----

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: linux-headers-3.8.0-17 3.8.0-17.27
ProcVersionSignature: Ubuntu 3.8.0-17.27-generic 3.8.6
Uname: Linux 3.8.0-17-generic x86_64
ApportVersion: 2.9.2-0ubuntu5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: mitchell 2039 F.... pulseaudio
Date: Tue Apr 9 07:56:50 2013
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=44202eef-4580-4844-9e5e-17436f2d39bd
InstallationDate: Installed on 2013-03-27 (12 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130326)
MachineType: Dell Inc. Dell System XPS L321X
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_AU:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.8.0-17-generic root=UUID=89891af3-60e2-4cb3-90e6-3280208bf5b9 ro quiet splash vt.handoff=7
PulseList:
 Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
 No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
 linux-restricted-modules-3.8.0-17-generic N/A
 linux-backports-modules-3.8.0-17-generic N/A
 linux-firmware 1.104
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/14/2012
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A07
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: 0.1
dmi.modalias: dmi:bvnDellInc.:bvrA07:bd08/14/2012:svnDellInc.:pnDellSystemXPSL321X:pvr:rvnDellInc.:rn:rvr:cvnDellInc.:ct8:cvr0.1:
dmi.product.name: Dell System XPS L321X
dmi.sys.vendor: Dell Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[AlJagal (al-jagal)]

Look like the same problem affected me. After rebooting after automatic upgrade to new 3.2.0-43-generic kernel, backlight get to 100% of brightness. Fn keys change brightness indicator only, not actual brightness. File /sys/class/backlight/intel_backlight/brightness unaccessible even with root privileges. The value in the files are:
actual_brightness 4882
bl_power 382089960
brightness 0
max_brightness 4882
type raw
uevent is empty.

It looks, like it should be reported here, because it's about 12.04 LTS and is not under attention in https://bugs.launchpad.net/bugs/1163720.

--------------------------------
db@NODE:/sys/class/backlight/intel_backlight$ ls -alF
total 0
drwxr-xr-x 3 root root 0 мая 22 17:06 ./
drwxr-xr-x 4 root root 0 мая 22 17:06 ../
-r--r--r-- 1 root root 4096 мая 22 17:06 actual_brightness
-rw-r--r-- 1 root root 4096 мая 22 17:54 bl_power
-rw-r--r-- 1 root root 4096 мая 22 17:06 brightness
lrwxrwxrwx 1 root root 0 мая 22 17:54 device -> ../../card0-LVDS-1/
-r--r--r-- 1 root root 4096 мая 22 17:54 max_brightness
drwxr-xr-x 2 root root 0 мая 22 17:54 power/
lrwxrwxrwx 1 root root 0 мая 22 17:06 subsystem -> ../../../../../../../class/backlight/
-r--r--r-- 1 root root 4096 мая 22 17:54 type
-rw-r--r-- 1 root root 4096 мая 22 17:06 uevent
db@NODE:/sys/class/backlight/intel_backlight$ sudo echo 0 > /sys/class/backlight/intel_backlight/brightness
bash: /sys/class/backlight/intel_backlight/brightness: Permission denied

[Francisco Cribari (cribari)]

I was able adjust the screen brightness using kernel 3.8.0-21, but there is a regression in kernel 3.8.0-22. Using the latter, I can no longer adjust the screen brightness using the Fn keys. Hardware is DELL XPS 13 and I am running Ubuntu Linux 13.04 (64 bit).

[ricolai (ricolai)]

Still affected in 3.8.0-24 and -25 :

* stuck at maximum level at startup and after a suspend
* Fn keys change brightness indicator only, not actual brightness

The brightness can be changed after running:

sudo bash -c "echo 0 > /sys/class/backlight/intel_backlight/brightness"

[postadelmaga (postadelmaga)]

I t could be the same problem reported here:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1229591

For me is still present in 15.04