changing screen brightness broken in Xubuntu (12.04 and 14.04)

Damian Kleiman fliakleiman at gmail.com
Sun Apr 27 02:35:46 UTC 2014


My brightness also stopped working on my last update, but i fixed it
by using the following command to make it brighter:

xgamma -gamma 1

I tried several numbers between 0 and 1 (0.25, 0.5, etc) and i
prefered one on my laptop.

Regards,
Damian

2014-04-26 21:26 GMT-03:00 Liviu Andronic <landronimirc at gmail.com>:
> On Sat, Apr 26, 2014 at 10:26 AM, PK <pliniusminor at gmail.com> wrote:
>> Try this:
>> https://sites.google.com/site/easylinuxtipsproject/display#TOC-Brightness-of-the-display-is-wrong-and-not-adjustable
>>
>> Those tweaks work fine on my machines. :-)
>>
>> Not really a Linux error, this; it has to do with BIOS / UEFI that's not
>> standard-compliant.
>>
> Thanks for the tips, but unfortunately none worked for me. I tried
> several workarounds.
> - with no obvious success:
> GRUB_CMDLINE_LINUX="acpi_osi=Linux"
>
> and
> update-grub
>
> - the following has no effect:
> xbacklight -set 20
>
> - and neither does this help:
> root at liv-inspiron:/home/geek# lspci | grep -i vga
> 00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT
> Integrated Graphics Controller (rev 09)
> 03:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
> [AMD/ATI] Venus PRO [Radeon HD 8850M] (rev ff)
> root at liv-inspiron:/home/geek# setpci -s 00:02.0 F4.B=20
> root at liv-inspiron:/home/geek# setpci -s 03:00.0 F4.B=20
>
>
> Any ideas on what else could be wrong? Thanks,
> Liviu
>
>> Regards, Pjotr.
>>
>>
>> 2014-04-26 9:56 GMT+02:00 Liviu Andronic <landronimirc at gmail.com>:
>>>
>>> Dear all,
>>> For several releases now (12.04 and 14.04) and across several machines
>>> (Lenovo 32-bit and Dell 64-bit), changing brightness settings is
>>> broken. It doesn't work whether I use the laptop buttons to modify
>>> screen brightness (to get the notification changing the percentage,
>>> but actual brightness NOT move one bit) or the Brightness panel-plugin
>>> from xfce4-power-manager (nothing really happens).
>>>
>>> Is this a known issue (or should I report it to Launchpad)? But more
>>> importantly, how can I change screen brightness in Xubuntu (install
>>> gnome-power-manager, etc.)?
>>>
>>> Regards,
>>> Liviu
>>>
>>> --
>>> Do you know how to read?
>>> http://www.alienetworks.com/srtest.cfm
>>> http://goodies.xfce.org/projects/applications/xfce4-dict#speed-reader
>>> Do you know how to write?
>>> http://garbl.home.comcast.net/~garbl/stylemanual/e.htm#e-mail
>>>
>>> --
>>> xubuntu-devel mailing list
>>> xubuntu-devel at lists.ubuntu.com
>>> https://lists.ubuntu.com/mailman/listinfo/xubuntu-devel
>>
>>
>>
>> --
>> xubuntu-devel mailing list
>> xubuntu-devel at lists.ubuntu.com
>> https://lists.ubuntu.com/mailman/listinfo/xubuntu-devel
>>
>
>
>
> --
> Do you know how to read?
> http://www.alienetworks.com/srtest.cfm
> http://goodies.xfce.org/projects/applications/xfce4-dict#speed-reader
> Do you know how to write?
> http://garbl.home.comcast.net/~garbl/stylemanual/e.htm#e-mail
>
> --
> xubuntu-devel mailing list
> xubuntu-devel at lists.ubuntu.com
> https://lists.ubuntu.com/mailman/listinfo/xubuntu-devel




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