Brightness controls doesn't work on a MacBook Pro 5.5 (ubuntu 12.04 LTS)

Question

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Brightness controls doesn't work on a MacBook Pro 5.5

I recently installed Ubuntu 12.04 LTS on my MacBook pro 5.5 (mid 2009). I have a problem with the brightness control. The thing is, when I try to reduce the brightness of my display which would help my battery and also not burn a hole through my eyes, is doesnt work.

I tried to use the system preference but nothing. The brightness control brightness slider doesn't even work. The only time the screen with change brightness is when ubuntu wants to go to sleep.

I went to the Ubuntu wiki or whatever it is and went through the MacBook Pro compatibility stuff to no avail.

I'm not sure if this has been asked allot or not, but I'm unable to find a solution. I am also new to ubuntu/linux but want to make the change and learn all I can.

P.s.- is there anything out there that will make the touch-pad work really well, I've already played with the mouse/track-pad settings that comes with Ubuntu? It's working but there seems to be some sluggishness and a few glitches here and there.

Thank you in advance =)

Solution

First, see this for instructions on changing brightness through the command line. If that doesn't work, it is likely a problem with your graphics driver and/or kernel version.

Note that by switching graphics driver, you can solve one problem but cause another. The default for nvidia has no power management, so people may switch to the proprietary driver if battery life on a laptop is important to them, but nvidia's drivers (being closed source) may not play nice with Ubuntu (leading to display issues like tearing in video).

If you want the nvidia driver, type in the terminal sudo apt-get install nvidia-current. After installing the driver, you'll need to enable brightness controls in /etc/X11/xorg.conf.

In /etc/X11/xorg.conf you should put:

Section "Device"
    Identifier     "NVIDIA GeForce"
    Driver         "nvidia"
    Option         "NoLogo" "True"
    Option         "RegistryDwords" "EnableBrightnessControl=1"
EndSection

"Identifier" is not so important unless you have other stuff referring to this device in your conf file. You can replace with more appropriate name if it's not an Nvidia GeForce type card. Everything else must be as written; "NoLogo" is to avoid the annoying Nvidia splash screen.

To edit the file using a GUI text editor, type gksudo gedit /etc/X11/xorg.conf in the terminal. Save changes and reboot... if all went well, you will now be using the new driver and brightness controls will work! If it doesn't work, you can check if you're using the new driver by typing in the terminal lspci -v | grep -i -A 15 vga. You should get something like:

02:00.0 VGA compatible controller: NVIDIA Corporation Device 08a3 (rev a2) (prog-if 00 [VGA controller])
[some lines omitted....]
Kernel driver in use: nvidia
Kernel modules: nvidia_current, nouveau, nvidiafb

Kernel drive in use should be nvidia, not nouveau.

Comments

[Chan-Ho Suh]

One question at a time please :-) For your brightness control, see if this works. If it doesn't, you might need to change graphics driver (if you are using the default). Post your trackpad question separately. It should be easy to fix.

[Barkerto]

Is there a preferred graphics driver people use over the default?

[Chan-Ho Suh]

You didn't say whether the command line worked :-) Well, switching drivers is a funny business.. you can fix one thing but break another. But in answer to your question, it depends on the graphics card you have. The default for nvidia has no power management, so people may switch to the proprietary driver if battery life on a laptop is important to them, but nvidia's drivers (being closed source) may not play nice with Ubuntu (leading to display issues like tearing in video).

[Barkerto]

Alright, Thank you. I'll check out the nvidia driver on their site (I'm guessing that's where I would find the drivers). But before that let me check the command line. I'll get back to you shortly.

[Barkerto]

Alright, so I tried the command lines in the link. It would change the brightness variables but it still wasn't changing the actual brightness of the screen. Could it possibly be that I'm running 64-bit instead of 32-bit?

[Chan-Ho Suh]

If you need an nvidia driver, for 12.04 you should be able to find it in an Ubuntu repository (without adding any PPA). On my system, sudo apt-get install nvidia-current worked. But as I cautioned earlier, this may break something else... although it doesn't seem difficult to change back (or switch back and forth, as some people do!). If you use the nvidia driver, you'll probably need to enable brightness controls in /etc/X11/xorg.conf.

[Chan-Ho Suh]

I don't think it's an architecture issue. I switched graphics drivers, from nouveau to nvidia, on 12.04 and got brightness controls to work, but it never worked before for me, even in 11.10. If the command line option isn't working, your options are looking kind of limited: you can change to the nvidia prop driver, but then it might mess up your compositing/effects (if you like that stuff). It might also decrease your video quality. But you can always try it and see.

[Barkerto]

I found the file for the /etc/X11/xorg.conf but this is all that is in it currently Section "Device" Identifier "Default Device" Option "NoLogo" "True" EndSection what would I need to do for enabling brightness? -Thanks for all your help so far @Chan-HoSuh

[Chan-Ho Suh]

You switched drivers? I believe the default nouveau driver will ignore xorg.conf, so there's no point in dealing with that if you didn't switch.

[Barkerto]

Yes, I switched, sorry I thought I typed that out. I'm not trying to input the proper formatting into the conf file now. But when I try to save it's telling me that I don't have permission to do that. I'm the only user of this computer, is this referring to admin only (which i am the admin of course), or something that I'm missing?

[Barkerto]

GOT IT!!!! Thank you so much! I just had to use sudo gedit /etc/X11/xorg.conf and then edit the file respectively. Thank you!!

[ialm]

In case someone has this problem and they don't have the file /etc/X11/xorg.conf: I installed Xubuntu 18.04, and the file /etc/X11/xorg.conf did not exist. Taking a look at this answer here, I found /usr/share/X11/xorg.conf.d/<nvidia>.conf and I added Option "RegistryDwords" "EnableBrightnessControl=1" to the configuration and it worked.

[ialm]

Actually, following the conventions according to the answer that I found in another answer here, I copied the original conf file from /usr/share/X11/xorg.conf.d/<nvidia>.conf to /etc/X11/xorg.conf.d/ and made my changes there.

[Yu Buntu]

By <nvidia>.conf do you mean, for example, the file on my system 10-nvidia.conf ?

[Yu Buntu]

I did what ialm did using 10-nvidia.conf (the only nvidia file in the /usr/share/X11/xorg.conf.d/ directory and it didn't work.