Upgrade to version 11.04, disable the laptop display back light

temporarily assigned to collect data

hello Diogo
Can you please run in a terminal
apport-collect -p linux 779166
Thanks
Fabio

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hello Fabio

To run the command i connect a external screen to my laptop.

Hello Diogo

Sorry but i cannot found anything wrong in kernel logs, so i'm asking if you can see the bios screen at startup.
If not that mean that the lamp is broken.

Fabio

Also if you see the bios screen at startup, please try to follow this guide to evaluate an acpi issue
https://wiki.ubuntu.com/DebuggingACPI#Trouble%20Booting
Thanks
Fabio

Also can you please install the latest mainline kernel clicking on these links in this order:

http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.39-rc5-oneiric/linux-headers-2.6.39-020639rc5_2.6.39-020639rc5.201105041556_all.deb

http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.39-rc5-oneiric/linux-headers-2.6.39-020639rc5-generic_2.6.39-020639rc5.201105041556_amd64.deb

http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.39-rc5-oneiric/linux-image-2.6.39-020639rc5-generic_2.6.39-020639rc5.201105041556_amd64.deb

And refere if it is working

Thanks
fabio

the kernel guys talk about the same problem here http://us.generation-nt.com/answer/2-6-38-rc2-acpi-backlight-control-missing-help-201853772.html

Hello
There's someone that want to test the latest upstream kernel above suggested, it is fully functional on my system, so please try it without problems and refere if it fix this issue.
Thanks
Fabio

Same problem with kernel v2.6.39-rc7-oneiric on ACER ASPIRE 4736Z (ubuntu natty)
thanks

Hello Alejandro
can you please attach here using the button below 'Add attachment or patch the file:
/var/log/dmesg
of the rc7 kernel
Thanks
Fabio

Hi Fabio,
attached you will find /var/log/dmesg and /var/log/Xorg.0.log
thanks
Alejandro

Sorry, using the suggested kernel doesn't fix the problem. I'm having this issue on gma 950 on a shuttle x50

I have same problem..
Mine is Acer Aspire 4736 with Intel GMA 4500M.
Linux - 2.6.38-8-generic #42-Ubuntu SMP Mon Apr 11 03:31:50 UTC 2011 i686 i686 i386 GNU/Linux

I run this command under no-backlight condition on terminal (I still can read my screen under flashlight):
sudo setpci -s 00:02.0 F4.B=00
and my back light is back!
but back light is off again after reboot, need to run that command again :(

All I did was add the setpci command into sudoers file (sudo visudo) so i don't need to type password when running setpci,
and make a new executable file contains that command, then make new startup entry to run that executable file every startup.

Now i have my back light function normally every startup..
Try this guys, who knows it can help you.

Hi,
it works using acpi_backlight=vendor as a kernel parameter

Just edit /boot/grub/grub.cfg and add "acpi_backlight=vendor" to GRUB_CMDLINE_LINUX_DEFAULT:

GRUB_CMDLINE_LINUX_DEFAULT="acpi_backlight=vendor quiet splash"

Then execute:

# sudo update-grub

Hello Alejandro,

Ok, I don't find the GRUB_CMDLINE_LINUX_DEFAULT: in /boot/grub/grub.cfg
Where i should add GRUB_CMDLINE_LINUX_DEFAULT="acpi_backlight=vendor quiet splash"?

thanks

Correction: Is't is in /boot/grub/grub.cfg but is in /etc/default/grub

Still not work in my machine.

PS: Booting my old kernel 2.6.35-28-generic, the backlight works again.

Guys I told you. I have solved the problem. Don't you read?

On Mon, May 16, 2011 at 8:07 PM, Diogo Coelho <email address hidden>wrote:

> PS: Booting my old kernel 2.6.35-28-generic, the backlight works again.
>
> --
> You received this bug notification because you are a direct subscriber
> of a duplicate bug (752165).
> https://bugs.launchpad.net/bugs/779166
>
> Title:
> Upgrade to version 11.04, disable the laptop display back light
>
> Status in NULL Project:
> Invalid
> Status in “linux” package in Ubuntu:
> Confirmed
>
> Bug description:
> My laptop is a Acer Aspire 5732Z. When the system finish the update
> and reboot, at startup the display back light is off.
>
> PS: I'm unable to register/login in
> https://help.launchpad.net/UserPreferences?action=login
> ---
> AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
> AplayDevices:
> **** List of PLAYBACK Hardware Devices ****
> card 0: Intel [HDA Intel], device 0: ALC272X Analog [ALC272X Analog]
> Subdevices: 1/1
> Subdevice #0: subdevice #0
> Architecture: amd64
> ArecordDevices:
> **** List of CAPTURE Hardware Devices ****
> card 0: Intel [HDA Intel], device 0: ALC272X Analog [ALC272X Analog]
> Subdevices: 1/1
> Subdevice #0: subdevice #0
> AudioDevicesInUse:
> USER PID ACCESS COMMAND
> /dev/snd/controlC0: crazygangster 1744 F.... pulseaudio
> Card0.Amixer.info:
> Card hw:0 'Intel'/'HDA Intel at 0xd6700000 irq 46'
> Mixer name : 'Realtek ALC272X'
> Components : 'HDA:10ec0272,10250212,00100001'
> Controls : 16
> Simple ctrls : 9
> DistroRelease: Ubuntu 11.04
> HibernationDevice: RESUME=UUID=354838ae-6be5-4e73-972c-1ea464b7741a
> InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64
> (20101007)
> MachineType: Acer Aspire 5732Z
> Package: linux (not installed)
> ProcEnviron:
> LANGUAGE=en
> LANG=pt_PT.utf8
> LC_MESSAGES=en_US.UTF-8
> SHELL=/bin/bash
> ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-8-generic
> root=UUID=224fcb50-9794-49f4-af28-72262aeb41d0 ro quiet splash vt.handoff=7
> ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
> RelatedPackageVersions:
> linux-restricted-modules-2.6.38-8-generic N/A
> linux-backports-modules-2.6.38-8-generic N/A
> linux-firmware 1.52
> RfKill:
> 0: phy0: Wireless LAN
> Soft blocked: no
> Hard blocked: no
> Tags: natty running-unity
> Uname: Linux 2.6.38-8-generic x86_64
> UpgradeStatus: Upgraded to natty on 2011-05-07 (1 days ago)
> UserGroups: adm admin audio cdrom dialout dip fax floppy fuse lpadmin
> netdev nopasswdlogin plugdev root sambashare tape vboxusers video
> dmi.bios.date: 08/03/2009
> dmi.bios.vendor: Acer
> dmi.bios.version: V2.06
> dmi.board.asset.tag: Base Board Asset Tag
> dmi.board.name: Aspire 5732Z
> dmi.board.vendor: Acer
> dmi.board.version: V2.06
> dmi.chassis.type: 10
> dmi.chassis.vendor: Acer
> dmi.chassis.version: V2.06
> dmi.modalias:
> dmi:bvnAcer:bvrV2.06:bd08/03/2009:svnAcer:pnAspire5732Z:pvrV2.06:rvnAcer:rnAspire5732Z:rvrV2.06:cvnAcer:ct10:cvrV2.06:
> dmi.product.name: Aspire 5732Z
> dmi.product.version: V2....

kernel 2.6.35-28-generic has the same problem with my acer aspire

using "acpi_backlight=vendor" as kernel parameter doesn't work for me :(
however, some people found solution from this thread: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/752165

in my case, its true that I can get my backlight work again by using setpci command and add it to my rc.local file. But when i change my screen resolution or running apps that needs to change screen resolution, my screen blank again :(

thats why i recommend to set a keyboard shortcut to run an executable file containing setpci command, so whenever we change resolution and blank screen again, all we need to do is only press that keyboard shortcut. at least it helped me a little.

Hello Ghozy
can ypou please install the latest mainline kernel, clicking on the followings links

1 - http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.0-rc1-oneiric/linux-headers-3.0.0-0300rc1_3.0.0-0300rc1.201105310830_all.deb

2 - http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.0-rc1-oneiric/linux-headers-3.0.0-0300rc1-generic_3.0.0-0300rc1.201105310830_amd64.deb

3 - http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.0-rc1-oneiric/linux-image-3.0.0-0300rc1-generic_3.0.0-0300rc1.201105310830_amd64.deb

And refere if it works
Thanks
Fabio

I will confirm that it is an Issue in the kernal, it stopped working on my Acer 5732Z when I updated to the most recent kernal. Which i can't see without a backlight

I have a Acer Aspire 4736z with a new installation of natty i386 from iso and had a blank screen when booting without "nomodeset".

I managed to work around my issue by adding the modules i915.o, drm.o , drm_helper.o and video.o to the initrd and booting with the kernel parameter acpi=force .

Latest kernels don't fix it i tested it with 3 rc7 and the bug remains

https://bugzilla.kernel.org/show_bug.cgi?id=35072

Please someone help us... this bug is critical

Same behavior on Shuttel X50, only boot-option "acpi=off" works.

thx for bug fixing.

This bug needs to be fixed. Following liveCD's / LiveDVD's do not work: ubuntu 11.04; Linux Mint 11; Mandriva 11... How do you expect to convert closed source users if even the screen does not work? Still at 10.04 LTS which works just fine except for brightness adjustment.

Acer machine with GMA4500 chipset.

Every event that turns off the screen's backlight lets the system unaccessible, even the energy saving ...

Tested the latest update to 11.10 at the weekend and the screen is still dark.

My diagnostic information can be found in bug 740893 at the below link.
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/740893/comments/8

Kernel 2.6.35.22 show a fully bright screen.

Kernel 2.6.38-8 was the first update i found the problem and no updates so far have corrected it.

Here is a workaround that did the trick on my acer 7715 with GMA4500 chip:

The following command has solved my problem.
"sudo setpci -s 00:02.0 F4.B=00"

The best is to have this command executed automatically at start up. You can do that by including that command in your /etc/rc.local file. To achieve this start up pc the pc with a 10.04 Live USB / Live CD. Go into the /etc/rc.local of the installed ubuntu 11.04 on your HD and insert "sudo setpci -s 00:02.0 F4.B=00" (without quotes) before the exit 0 command.

My rc.local looks like this:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

sudo setpci -s 00:02.0 F4.B=00
exit 0

Hope this will solve problem.

Proudly copied from Angel Zone on:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/752165

Thanks for that, however the command reports missing width.

I'm guessing this has something to do with the B=00 part but I don't know what hex value to set, can you shed any light on the situation?

That solution only works after boot / resume, and with acpi_backlight=vendor....

And in my case the backlight control it also inverted....

@Gary

I am sorry, but I can't . I just reported the solution from the duplicate bug (752165) that solved my unlit bakclight problem. You might try the original author (Angel Zone) to shed any backlight on this situation.

My experience is that The "sudo setpci -s 00:02.0 F4.B=00" command only turns on the backlight from 0 to 100%. But the backlight controls will not work.

@cryd_be

Thanks for your reply, i've now seen the light ;)

I've added this (sudo setpci -s 00:02.0 F4.B=00) command to the rc.local file and the screen is now starting up.

I can also report that supertuxkart does not cause the screen to go dim again, as reported in another bug regarding this problem, also the brightness controls still do not function as you said.

@cgonzalez and anyone else:

Since the screen also goes dark when resuming from suspend or other purposes, and rc.local doesn't get run at that time, I've also added the relevant setpci command to root's crontab, to be executed every minute. That way, the screen isn't black for more than a minute.

(I might add that the machine affected belongs to a non-technical friend of mine who doesn't want anything complex.)

I have an acer Aspire 5732Z with intel GMA 4500M graphics running Linuxmint 11. The sudo setpci fix as outlined in post #33 works for me as long as I boot on battery.

If I connect the laptop to a power source and boot I end up with a blank screen. However I can then get the login screen by hitting Ctrl Alt Del
Works fine after that

I have prepared a PPA test kernel for Ubuntu 11.10 (Oneiric) including a patch which might address the "inverted backlight brightness" or "backlight off at startup" problems, for laptops with a Intel GPU's only:

    https://launchpad.net/~kamalmostafa/+archive/inverted-backlight

Feedback to this bug report will be appreciated.

Kamal,
the patched kernel solves the backlight off at startup problem on my HP dm-4 notebook (acpi_backlight=vendor).
thanks
Alejandro

I see no change with the patched kernel. :(

The machine is Acer Aspire 5732Z.

@Alejandro- Thanks for your report that the patched 'inverted-backlight' kernel (from comment #56) fixes it for your HP dm-4 notebook... Do you still have the Acer Aspire 4736Z that you mentioned in #27, and could you test it on that machine?

@Riccardo- Be sure to try the patched kernel along with using the kernel parameter "acpi_backlight=vendor" as described on the 'inverted-backlight' PPA details page (linked from comment #56) -- some systems will need that parameter to enable the patched code.

@Kamal i have an Acer Aspire and had the backlight issue, tried the acpi_backlight change to the grub but didnt notice any improvement ie screen was still dark at startup. I then used the decrease backlight and this increased the brightness, so it seems that the settings are inverted as using the hardware keys to decrease the backlight actually increases the screen brightness.

Hello, just to answer to kamal: the patched kernel, with the parameter "acpi_backlight=vendor" does nothing... I am still with 2.6.35-30.

Diogo Coelho, thank you for reporting this and helping make Ubuntu better. Natty reached EOL on October 28, 2012.
Please see this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We were wondering if this is still an issue in a supported release? If so, could you please test for this with the latest development release of Ubuntu? ISO images are available from http://cdimage.ubuntu.com/daily-live/current/ .

If it remains an issue, could you please run the following command in the development release from a Terminal (Applications->Accessories->Terminal), as it will automatically gather and attach updated debug information to this report:

apport-collect -p linux <replace-with-bug-number>

Also, could you please test the latest upstream kernel available following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue. Please do not test the kernel in the mainline kernels archive directory daily folder. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested. For example:
kernel-fixed-upstream-v3.10-rc5

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description. As well, please remove the tag:
needs-upstream-testing

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

As well, please remove the tag:
needs-upstream-testing

If you are unable to test the mainline kernel, please comment as to why specifically you were unable to test it and add the following tags:
kernel-unable-to-test-upstream
kernel-unable-to-test-upstream-VERSION-NUMBER

Once testing of the upstream kernel is complete, please mark this bug's Status as Confirmed. Please let us know your results. Thank you for your understanding.

Helpful bug reporting tips:
https://help.ubuntu.com/community/ReportingBugs