LinuxQuestions.org - Installing a Brightness Driver ( nvidiabl )

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Installing a Brightness Driver ( nvidiabl )

Hello,

i installed the nvidiabl Driver from

https://github.com/guillaumezin/nvidiabl

because i cant control the display brightness on my notebook (its always at 100%).

So i opened the

nvidiabl-dkms_0.80_all.deb

file with Ubuntu Software Center and installed the package. After it was successfully installed, i tried to reduce the Brightness level with FN keys, but it doesnt work.

So i read, that i must add the line "nvidiabl" to /etc/modules.

I did this by typing sedo nano -w /etc/modules

I successfully added the line and rebooted. But i am still not able to change the screen Brightness, what do i have to do?

My Notebook is a Acer Aspire TimelineX 5830TG

Hope you can help :)

Greetings,

Quaditz

I just did this last night in Fedora 17x64 on a Lenovo T420 with nVidia drivers installed.

check your xorg.conf and add this line:

Code:

Option "RegistryDwords" "EnableBrightnessControl=1"

I found this on fedora forums http://forums.fedoraforum.org/showthread.php?t=279973

xorg.conf can be found in /etc/X11/
I recommend making a backup of the xorg.conf and add the above line between
Then restart the xserver or restart the system.

I do not have the computer from last night available at the time to print exactly where it goes but I remember it goes between the tags in xorg.conf.

Hope this helps.

I had the same problem on an HP laptop, and it was burning my retinas. I've tried the xorg.conf solution and a host of others, to no avail. I have an AMD/ATI card, but I might be able to help:

A couple options are to download and install Redshift (http://jonls.dk/redshift/).
Using the following command might work:

Code:

redshift -l 0:0 -t 5800:5800 -r -b *brightness-value*&

See redshift's man page for argument descriptions, but *brightness-value* is a decimal between 0 and 1.

Anyways, because I adjust screen brightness every time I get on my computer, I wrote a Python script.

Just make sure you check and install the dependencies (see below), save the script to a file, chmod +x, and off you go.

Happy programming.

Code:

#!/usr/local/bin/python3

'''

Controls screen brightness on notebooks with switchable graphics cards 

(i.e. AMD/Intel) when proprietary drivers and notebook toggle switches

are inoperative.  Though Redshift was originally designed to automatically 

change screen temperature based on lat/long and time of day, its ability  

to alter screen brightness is exploited in this script.



Edit #! above (Python path), as required for your system.



Package Dependencies:



redshift - http://jonls.dk/redshift/

psutil - http://pypi.python.org/pypi/psutil

python - http://www.python.org/download/releases/

python-devel - install python from source gives you python-devel, or

              you can download a distro-specific package.



Written in Python 3.3

'''

import psutil

import os



def GetRedshiftPID():  #Get Process ID (PID) for redshift

    for proc in psutil.process_iter():

        if proc.name == "redshift":

            return proc.pid  #Returns redshift PID as integer

    return 0                #Returns 0 if redshift is not running



RedshiftPID = GetRedshiftPID()



def StartRedshift():

    brightness=input("Enter desired screen brightness (0-10): ")

    brightness=brightness.rstrip()  #Strips whitespace characters

    try: 

        brightness=float(brightness)  #Attempts to convert user input to a float

        if brightness not in range(0,11):

            print("Enter an integer between 1 and 10.")

            StartRedshift()  #Retry if user input is not an integer between 1 and 10

        else:

            if RedshiftPID != 0:  #If redshift is running, kill it

                os.system("kill " + str(RedshiftPID))

            if GetRedshiftPID() > 0:  #If redshift is running after first kill attempt, abort.

                print("Unable to kill Redshift. Exiting...")

                quit()

            brightness=brightness/10  #Convert brightness to float for use in redshift call

            os.system("redshift -l 0:0 -t 5800:5800 -r -b " + str(brightness) + "&")  #redshift to runs in background

            print("Script Complete.  Exiting...")

    except:

        print("Enter an integer between 1 and 10.")  #If exception is caught in conversion, retry

        StartRedshift()



StartRedshift()  #Begins program

If all this does not work you should take a look at /sys/class/backlight/acpi_video0/

there are files "actual_brightness", "max_brightness", "brightness"

Code:

cat /sys/class/backlight/acpi_video0/actual_brightness

cat /sys/class/backlight/acpi_video0/max_brightness

you can set another value for the brightness with (as root)

Code:

echo "4" > /sys/class/backlight/acpi_video0/brightness

where you have to use a useful value instead of 4, something between max_brighness and 0

Markus

@Markush

Quote:

...you should take a look at /sys/class/backlight/acpi_video0/

I've tried those, too - also to no avail.

Interesting question, though: If none of the known solutions are working on my system, how on God's green earth does Redshift work? Which values is Redshift altering?