Fn+F6 & F7 does not work for screen brightness in 12.04

Question

I am using Toshiba Portege R835-P70 and function keys work as expected on Windows but they do not on Ubuntu 12.04. For e.g. Fn+F6 and Fn+F7 are supposed to change screen brightness but do not work.

What is the solution for this issue?

I tried adding GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_backlight=vendor“ to /etc/default/grub, but it introduces an additional problem in that the laptop wakes up to a faintly visible dark screen from hibernation.

I know this is an old issue, but if it is so common, why isn't there a simple solution to it and why isn't it incorporated in latest versions of Ubuntu?

Thanks.

score 0 · Answer 1 · edited Jun 15 '17 at 19:55

0

Try this:

open your terminal and type this

sudo gedit /etc/default/grub

and find a line

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

and change it to like that. then close the editor and do sudo update-grub and give a restart. check it out now.

edited Jun 15 '17 at 19:55

Ravexina

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answered May 26 '12 at 06:29

Raja G

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I have already tried doing that. Above introduces an additional problem in that the screen boots to very faintly visible dark upon waking up from hibernation. – abhinavkulkarni May 26 '12 at 07:03

score 0 · Answer 2 · edited Jun 15 '17 at 19:55

0

See a solution that worked on my Protege 705-P35 at Toshiba Portege Z830\Z835 [Linux Laptop Wiki]. To make the new script executable, type:

sudo chmod 755 /etc/pm/sleep.d/restore_brightness

edited Jun 15 '17 at 19:55

Ravexina

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answered Dec 10 '12 at 07:36

Doug

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Welcome to Ask Ubuntu! Whilst this may theoretically answer the question, [it would be preferable](http://meta.stackexchange.com/q/8259) to include the essential parts of the answer here, and provide the link for reference. – Oyibo Dec 10 '12 at 08:38

score 0 · Answer 3 · edited Oct 02 '15 at 20:29

0

The following edit to /etc/default/grub helped me:

sudo nano `/etc/default/grub`

and then change the GRUB_CMDLINE_LINUX_DEFAULT to:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=force acpi_backlight=vendor"

Then run update-grub and reboot.

_Source

edited Oct 02 '15 at 20:29

Fabby

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answered Dec 22 '12 at 14:06

Venem

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@snoop: Could you please review my [edits](http://askubuntu.com/posts/231744/revisions)? – Fabby Oct 02 '15 at 20:30

Fn+F6 & F7 does not work for screen brightness in 12.04

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