Pressing Fn + Brightness Up and Down results in the brightness indicator jumping randomly up and down, with no change to the actual brightness. This laptop uses a nvidia graphics card for display and brightness which is not supported by ubuntu's default configuration.
There is only one way that I have found to actually make the brightness go up and down:
1. Add acpi_osi=Linux acpi_backlight=vendor ro to /boot/grub/grub.cfg
2. Type echo 5 > /sys/class/backlight/nv_backlight/brightness
And even with acpi_backlight=vendor switched on, using the Fn key to affect brightness still does not work, presumably because its trying to use dell_backlight, which does nothing.
Output of ls /sys/class/backlight with acpi_backlight=vendor:
root@r-Inspiron-1370:~# ls /sys/class/backlight
dell_backlight nv_backlight
root@r-Inspiron-1370:~#
Normally this only contains acpi_video0 (off top of head so might be a typo). I think someone needs to make a patch to fix this bug.
---
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu7
Architecture: i386
ArecordDevices:
**** List of CAPTURE Hardware Devices ****
card 0: Intel [HDA Intel], device 0: ALC272 Analog [ALC272 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: r 2030 F.... pulseaudio
/dev/snd/controlC0: r 2030 F.... pulseaudio
Card0.Amixer.info:
Card hw:0 'Intel'/'HDA Intel at 0xf1400000 irq 46'
Mixer name : 'Realtek ALC272'
Components : 'HDA:10ec0272,10280418,00100001'
Controls : 11
Simple ctrls : 6
Card1.Amixer.info:
Card hw:1 'NVidia'/'HDA NVidia at 0xf1000000 irq 16'
Mixer name : 'Nvidia GPU 0b HDMI/DP'
Components : 'HDA:10de000b,10de0101,00100100'
Controls : 24
Simple ctrls : 4
DistroRelease: Ubuntu 12.04
HibernationDevice: RESUME=UUID=466a8816-87d1-4087-869f-2e4d02cbf791
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
MachineType: Dell Inc. Inspiron 1370
Package: linux (not installed)
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcFB: 0 nouveaufb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-24-generic root=UUID=ce5b90bb-32e1-4bb1-98c0-ba189425a158 ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 3.2.0-24.39-generic 3.2.16
PulseList:
Error: command ['pacmd', 'list'] failed with exit code 1: Home directory /home/r not ours.
No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
linux-restricted-modules-3.2.0-24-generic N/A
linux-backports-modules-3.2.0-24-generic N/A
linux-firmware 1.79
SourcePackage: linux
Tags: precise precise
Uname: Linux 3.2.0-24-generic i686
UpgradeStatus: Upgraded to precise on 2012-05-04 (23 days ago)
UserGroups: disk
dmi.bios.date: 10/28/2009
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A02
dmi.board.name: 016YGK
dmi.board.vendor: Dell Inc.
dmi.board.version: A02
dmi.chassis.asset.tag: None
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: A02
dmi.modalias: dmi:bvnDellInc.:bvrA02:bd10/28/2009:svnDellInc.:pnInspiron1370:pvrA02:rvnDellInc.:rn016YGK:rvrA02:cvnDellInc.:ct8:cvrA02:
dmi.product.name: Inspiron 1370
dmi.product.version: A02
dmi.sys.vendor: Dell Inc.
---
ApportVersion: 2.4-0ubuntu6
Architecture: i386
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: r 2153 F.... pulseaudio
/dev/snd/controlC0: r 2153 F.... pulseaudio
DistroRelease: Ubuntu 12.10
HibernationDevice: RESUME=UUID=466a8816-87d1-4087-869f-2e4d02cbf791
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
MachineType: Dell Inc. Inspiron 1370
Package: linux (not installed)
ProcEnviron:
TERM=xterm
PATH=(custom, user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcFB: 0 nouveaufb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-10-generic root=UUID=ce5b90bb-32e1-4bb1-98c0-ba189425a158 acpi_osi=Linux acpi_backlight=vendor ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 3.5.0-10.10-generic 3.5.1
RelatedPackageVersions:
linux-restricted-modules-3.5.0-10-generic N/A
linux-backports-modules-3.5.0-10-generic N/A
linux-firmware 1.88
Tags: quantal running-unity
Uname: Linux 3.5.0-10-generic i686
UpgradeStatus: Upgraded to quantal on 2012-08-14 (1 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare
dmi.bios.date: 10/28/2009
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A02
dmi.board.name: 016YGK
dmi.board.vendor: Dell Inc.
dmi.board.version: A02
dmi.chassis.asset.tag: None
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: A02
dmi.modalias: dmi:bvnDellInc.:bvrA02:bd10/28/2009:svnDellInc.:pnInspiron1370:pvrA02:rvnDellInc.:rn016YGK:rvrA02:cvnDellInc.:ct8:cvrA02:
dmi.product.name: Inspiron 1370
dmi.product.version: A02
dmi.sys.vendor: Dell Inc.
This affects all versions of ubuntu including 11.10 and 12.04.