Screen brightness on Acer 4810T

[aioan]

with "nomodeset" it works but makes the desktop slow to a crawl.

On my laptop worked great while in BIOS v1.10

After upgrading to v1.31 using the brightness control brings the system to a "low power" mode making it unusable... Any application using 3d is REALLY slow and crashes when trying to run glxgears or Google Earth.

Any ideas?

Regards,

[executorvs]

I'm trying to draw more attention to this bug on launchpad as it also affects other timeline models and I suspect a few of the other Aspire series as well.

there is a bug report at https://bugs.launchpad.net/ubuntu/+s...el/+bug/446717

I have marked as duplicates all of the bugs related to the changes in how the brightness keys have failed over time.

if anyone with either a 3810(TZ/TG) or 4810(TZ/TG) or 5810TG could post exact details of how this bug affects there computer under lucid it would be appreciated.

[jsampaio57]

you need to
sudo update-grub

cheers...

[jsampaio57]

It's my grub:

I can't change blacklight brightness
Help me
I use Ubuntu 9.10 ,my laptop: ASPRIRE 4736Z

you need to:
sudo update-grub

cheers...

[executorvs]

there seem to be two problems, one is with a lot of acers and the other is with intel powered graphics cards.
The acer problem is on launchpad https://bugs.launchpad.net/bugs/397617 and you may find a work around in one of the listed duplicates.

The bug affecting the intel graphics cards is related to KMS and is on launchpad at https://bugs.launchpad.net/bugs/397617 again there are workarounds listed.

the larger annoyance in all of this is that in many cases the fixes that work for some hardware don't work for others it can be a firmware difference which makes or breaks the effectiveness of any of the workarounds listed.. I just want brightness buttons that work

[hesapotman]

I am using ...

Laptop: Acer Aspire 4736z
Graphics: Intel GMA 4500M
OS: Ubuntu Maverick Meerkat (10.10)
Kernel: 2.6.35-23-generic

And I managed to solve this problem for myself using some modified scripts/advice from other forum posts.

First, create a folder on your desktop called "brightness", go into the directory, create two files: brup and brdn, and set their permissions to execute.

mkdir /home/<YOUR_USERNAME>/Desktop/brightness

cd /home/<YOUR_USERNAME>/Desktop/brightness

touch brup brdn

chmod 0755 br*

Next, we'll edit "brup"

gedit brup

Adding the following text to "brup"

#!/bin/bash

# these are the possible values:
# 00  19 32 4b 64 7d 96 af c8 e1 ff
# 100 90 80 70 60 50 40 30 20 10 00

Current=`sudo setpci -s 00:02.0 F4.B`
case $Current in
  e1)
    sudo setpci -s 00:02.0 F4.B=c8
  ;;
  c8)
    sudo setpci -s 00:02.0 F4.B=af
  ;;
  af)
    sudo setpci -s 00:02.0 F4.B=96
  ;;
  96)
    sudo setpci -s 00:02.0 F4.B=7d
  ;;
  7d)
    sudo setpci -s 00:02.0 F4.B=64
  ;;
  64)
    sudo setpci -s 00:02.0 F4.B=4b
  ;;
  4b)
    sudo setpci -s 00:02.0 F4.B=32
  ;;
  32)
    sudo setpci -s 00:02.0 F4.B=19
  ;;
  19)
    sudo setpci -s 00:02.0 F4.B=00
  ;;
  *)
    sudo setpci -s 00:02.0 F4.B=00
  ;;
esac

Now we "Save" the file and "Close" gedit.

Next, we'll edit "brdn"

gedit brdn

Adding the following text to "brdn"

#!/bin/bash

# these are the possible values:
# 00  19 32 4b 64 7d 96 af c8 e1 ff
# 100 90 80 70 60 50 40 30 20 10 00

Current=`sudo setpci -s 00:02.0 F4.B`
case $Current in
  00)
    sudo setpci -s 00:02.0 F4.B=19
  ;;
  19)
    sudo setpci -s 00:02.0 F4.B=32
  ;;
  32)
    sudo setpci -s 00:02.0 F4.B=4b
  ;;
  4b)
    sudo setpci -s 00:02.0 F4.B=64
  ;;
  64)
    sudo setpci -s 00:02.0 F4.B=7d
  ;;
  7d)
    sudo setpci -s 00:02.0 F4.B=96
  ;;
  96)
    sudo setpci -s 00:02.0 F4.B=af
  ;;
  af)
    sudo setpci -s 00:02.0 F4.B=c8
  ;;
  c8)
    sudo setpci -s 00:02.0 F4.B=e1
  ;;
  *)
    sudo setpci -s 00:02.0 F4.B=e1
  ;;
esac

Now we "Save" the file and "Close" gedit.

Next, we would like to put those files somewhere in the System. I chose to create a directory called "brightness" in the "/usr/bin" path. After that, we copy the scripts we just wrote (brup & brdn) to that path.

sudo mkdir /usr/bin/brightness

sudo cp * /usr/bin/brightness

Now we want to change the "sudoers" file so that we can execute these scripts without having to enter a password each time.

sudo gedit /etc/sudoers

After the line "#Cmnd alias specification", we want to add a line aliasing our brightness commands.

# Cmnd alias specification
Cmnd_Alias BRIGHT_CMDS = /usr/bin/brightness/brup, /usr/bin/brightness/brdn

And at the very bottom of the file (AFTER the line "%admin ALL=(ALL) ALL"), we want to add a line permitting all users to execute those scripts without having to enter a password.

ALL ALL=(ALL) NOPASSWD: BRIGHT_CMDS

Now we "Save" the file and "Close" gedit.

Painful terminal crap is over ... So close it!

Now we go to the menu-bar selecting from the cascading options: System -> Preferences -> Keyboard Shortcuts

In the box that opens, click the "Add" button and enter the following:

Name: Brightness Up
Command: gksudo /usr/bin/brightness/brup

And click "Apply".

Next we click the "Add" button again and enter the following:

Name: Brightness Down
Command: gksudo /usr/bin/brightness/brdn

And click "Apply".

Now, if you look at the bottom of the list of Keyboard Shortcuts, you should see two "Custom Shortcuts" (the ones you just entered).

If you click on the right side of the listings (in the "Shortcut" column), you will be able to enter a keystroke (or combination) that will activate your "Brightness Up" and "Brightness Down" actions.

For me, I chose CTRL+WIN+RIGHT_ARROW for "Brightness Up" and CTRL+WIN+LEFT_ARROW for "Brightness Down. But you can use any keystrokes you like as long as they don't conflict with other existing shortcuts.

Now click "Close" in the "Keyboard Shortcuts" box.

THAT'S IT! You should be good to go now. Give it a try with your selected keystrokes and see if it works for you. I sure hope this helps someone.

[hesapotman]

there seem to be two problems, one is with a lot of acers and the other is with intel powered graphics cards.
The acer problem is on launchpad https://bugs.launchpad.net/bugs/397617 and you may find a work around in one of the listed duplicates.

The bug affecting the intel graphics cards is related to KMS and is on launchpad at https://bugs.launchpad.net/bugs/397617 again there are workarounds listed.

the larger annoyance in all of this is that in many cases the fixes that work for some hardware don't work for others it can be a firmware difference which makes or breaks the effectiveness of any of the workarounds listed.. I just want brightness buttons that work

Yes indeed, different hardware reacts differently. For example, the "workaround" scripts I found specified brightness values in hex where "FF" was supposed to be 100% brightness and 19 was supposed to be 10% brightness. Well it only took me a moment to figure out that those numbers were exactly ***-backwards (for MY hardware). So I modified the scripts such that "E1" was 10% and "00" was 100%.

So for goodness sake, if anyone attempts to use the fix I listed above, PLEASE be sure to note my hardware/software specs. If you're not using the same hardware/software, I have no idea what might happen when you go messing around.

[Noob-untu]

Hi everyone,
hesapotman,

I just wanted to say that I tried your thingy and it worked for me. Wow, I didn't really have much hope, after all the solutions I have tried.

Downside: Power manager remains unable to change brightness, but hey, at least, until a comprehensive solution is found, my eyes won't drop dead now.

Downside: Sometimes, it gets a little stuck for a few seconds, and a window with the title "Starting Administrative Application" can be seen in the task bar, and the cursor gets into "loading" mode. CPU gets 'intense' while trying to sort that out.

Downside: Also, I get the impression that the max brightness I can set is dimmer than it used to be. Is it possible to change the range of brightness set in the brup and brdn files? (I'm more interested in learning this out of curiosity than of practical reasons, so you don't really have to bother explaining).

But all in all, thanks a lot, I appreciate that you bothered to write a fool-proof guide!

Acer Extensa 5235
Ubuntu 10.04
GMA 4500M

[hesapotman]

Hi everyone,
hesapotman,

I just wanted to say that I tried your thingy and it worked for me. Wow, I didn't really have much hope, after all the solutions I have tried.

Downside: Power manager remains unable to change brightness, but hey, at least, until a comprehensive solution is found, my eyes won't drop dead now.

Downside: Sometimes, it gets a little stuck for a few seconds, and a window with the title "Starting Administrative Application" can be seen in the task bar, and the cursor gets into "loading" mode. CPU gets 'intense' while trying to sort that out.

Downside: Also, I get the impression that the max brightness I can set is dimmer than it used to be. Is it possible to change the range of brightness set in the brup and brdn files? (I'm more interested in learning this out of curiosity than of practical reasons, so you don't really have to bother explaining).

But all in all, thanks a lot, I appreciate that you bothered to write a fool-proof guide!

Acer Extensa 5235
Ubuntu 10.04
GMA 4500M

Hey, I'm really glad that worked for you! I know some of the gurus get their panties all bunched up at having such a detailed guide (they consider it condescending). But it's important to remember that not every Ubuntu user is a computer wizard, and sometimes people need a step-by-step guide telling them every little detail.

Yes, having the "Starting Administrative Application" thing show up in the taskbar - even for a moment - is a pain. But it's much better than having to enter the password for each 10% brightness step. However, I've never had any issues with the scripts eating CPU or causing slow-down. I guess it would be best not to change brightness during some mission-critical real-time apps then.

I have found the built-in Power Manager to be pretty much worthless at controlling the monitor (it won't even put my monitor to sleep correctly). It's just one more of the "default apps" that Canonical has failed to repair for a long time now. Anyway, if you're having that problem also, I used a fix where I replaced gnome-screensaver with xscreensaver. Topic is here: http://ubuntuforums.org/showthread.php?t=1358946

As far as I am aware, display brightness is set as a 1-byte hexadecimal value. The range is from 00 to FF (in normal decimal, that's 0 to 255). The maximum brightness setting (00) is as low as the value can go, so it's probably the brightest your monitor can get. It's possible that the backlights in your monitor are aging and aren't as bright as they used to be. Or it's possible that you're remembering your monitor's brightness being brighter than it really was.

Cheers!

[tuxonapogostick]

Xmodmap might solve your problem.
I suggest that you do:
1. get the keysym name of the key via xev that you would like to use for screen brightness adjustment
2. find the keysym name for the screen brightness
3. do :

xmodmap -e " keysym function4 = Brightness"

for example. This is just an example actual keysym names will probably different than "function4" or "Brightness".