Screen brightness does not change on Toshiba Satellite in Karmic

[filipejps]

Same problem here after changing /etc/default/grub:

"Cannot get laptop panel brightness"

I've a Toshiba Satellite T130

[squee]

Same problem here after changing /etc/default/grub:

"Cannot get laptop panel brightness"

I've a Toshiba Satellite T130

I have to bump this, sorry.

Same problem even with the newest updates. Also running a Toshiba t130.

[Ganda1f]

I upgraded from jaunty to karmic on Acer 4736, and the brightness control no longer works! The fix that was working on jaunty is also not working. I have tried other options mentioned here too, (except installing 64-bit ubuntu) and still brightness control does not work....

[squee]

BUMP

MODS this is still not solved for 10.04

Should a new thread be created or this one just edited?

[jabbermacy]

I don't even HAVE my T135 yet but I'm going to bump this anyway! The screen brightness issue unsolved means I can't use Linux on this laptop! BIG BUMMER. Any new information on the problem or fixes??

[larmoe01]

Applying "nomodeset acpi_backlight=vendor" to grub, will crash Xorg, since the most recent version of Xorg doesn’t support this string.
For the T130 I found this workaround, witch will dim the screen brightness and extend the battery time. This workaround will not allow you to adjust the brightness with the fn keys.

You can manually adjust the brightness with setpci:

sudo setpci -s 00:02.0 F4.B=#

were # is a value from 0 - 99.

This can be used in ACPI events to control the brightness according to the state of the AC adapter.

sudo touch /etc/acpi/brightness.sh
sudo chmod 755 /etc/acpi/brightness.sh
sudo nano -w /etc/acpi/brightness.sh

Copy paste the lines below to brightness.sh:

#!/bin/sh

if [ "`sed -e "s/.[^ ]* *//" /proc/acpi/ac_adapter/ACAD/state`" = "on-line" ]
        then
                logger "ACPI: AC adapter is on-line, brightness up..."
                sudo setpci -s 00:02.0 F4.B=99

        else
                logger "ACPI: AC adapter is off-line, brightness down..."
                sudo setpci -s 00:02.0 F4.B=40

fi

Now we have to edit the events to trigger brightness.sh. As root type

echo action=/etc/acpi/brightness.sh >> /etc/acpi/events/battery
echo action=/etc/acpi/brightness.sh >> /etc/acpi/events/ac
restart acpid

This will dim the brightness when laptop goes on battery, an brighten the screen when the AC adapter is connected.

Reference: http://www.gentoo-wiki.info/ACPI/Configuration

[cnu1]

You should edit the following section:

## additional options to use with the default boot option, but not with the
## alternatives
## e.g. defoptions=vga=791 resume=/dev/hda5
# defoptions=quiet splash

to

## additional options to use with the default boot option, but not with the
## alternatives
## e.g. defoptions=vga=791 resume=/dev/hda5
# defoptions=quiet splash nomodeset acpi_backlight=vendor

And run grub-update as root:

sudo grub-update

That should fix it.

Firstly a big thanks, it worked for me. Just for others who may still be having the problem. The key word is "nomodeset"

1. my default_grub line looks like this: GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_osi=Linux nomodeset acpi_backlight=vendor splash"
2. Then I ran "sudo update-grub" and "sudo update-grub2"
3. Finally restart. For me I was able to see the slidebar in the power management preferences

[Naguz]

Nomodeset isn't an option for many, since any half-recent intel graphics driver requires it. (I'm guessing you have one without intel graphics unless the intel drivers weren't updated with Jaunty - In which case they are very old.)

I'm getting kind of dired of the manual setcpi thingy, Different location needs different backlight.

[Pataforce8]

Hey all
I'm having the same problem, unfortunately using the nomodeset fix crashes my xserver and the setpci fix does not change the brightness for me. Any help?

[deibhaid]

Hey guys,

I took some of the previous bits of advice that I found around and I made scripts that I bound to the fn+brightnessup and fn+brightnessdown keys. I used the Compizconfig settings manager's commands section to bind each script to the brightness keys.

I am sure the bash scripts aren't perfect and could be easily modified to be more efficient, bit this works great for my purposes. Note: for this to work, one must run setpci with root permissions. chmod 4755 works, but of course it creates quite a potential security hole. perhaps adding the program to the sudoers list with your username would be acceptable.

**************************************************
brightness_up.sh
**************************************************
#!/bin/sh
test -f /tmp/brightness || echo 99 > /tmp/brightness
brightness=$((`cat /tmp/brightness`+5))
if [ $brightness -gt 99 ] ; then
brightness=99;
fi
echo $brightness > /tmp/brightness
export brightness
setpci -s 00:02.0 F4.B=`cat /tmp/brightness`



**************************************************
brightness_down.sh
**************************************************
#!/bin/sh
test -f /tmp/brightness || echo 6 > /tmp/brightness
brightness=$((`cat /tmp/brightness`-5))
if [ $brightness -lt 0 ] ; then
brightness=0;
fi
echo $brightness > /tmp/brightness
export brightness
setpci -s 00:02.0 F4.B=`cat /tmp/brightness`