Lower brightness of backlight display of MacBook Pro with Nvidia graphics adapter

[ChittiBabu]

right now I am having MacBook(Pro). Nvidia graphics adapter installed on the laptop is at maximum brightness after resuming from the suspend. Driver is showing the last recently set values. This particular issue can be fixed by simply resending the value at the time of suspend. Ca n you tell me who its work?

[Samaria]

The above mentioned thing can be done in following manner.
You have to install deb package and reload the module.

sudo dpkg -i mbp-nvidia-bl-dkms_0.11_all.deb
sudo rmmod mbp_nvidia_bl
sudo modprobe mbp_nvidia_bl

you have to set the display brightness to low value

echo 1 | sudo tee /sys/class/backlight/mbp_backlight/brightness

in case it is not working for you than you have to remove below mentioned package.

sudo apt-get remove --purge mbp-nvidia-bl-dkms

[ChittiBabu]

Below mentioned code is not working for me. I am getting ‘Permission Denied’ error message while running the command. Can you help me out?

sudo echo 1 > /sys/class/backlight/mbp_backlight/brightness

[Sasuke Uchiha]

Yes it will not work for you since it is two different commands. You will not require sudo for echo command. However you will need sudo for '>' command since you are looking to pipe to the protected file.
so you should execute below mentioned command.

echo 1 |sudo tee /sys/class/backlight/mbp_backlight/brightness

[Anjan1990]

You can try below mentioned steps and let me know whether it was useful to you.

• You should boot the computer and run below thing. you should run /etc/acpi script under root directory.

video_brightnessup.sh

#!/bin/bash

CURRENT=`cat /sys/class/backlight/mbp_backlight/actual_brightness`


case "$CURRENT" in

15)
echo -n 15 > /sys/class/backlight/mbp_backlight/brightness;
;;
14)
echo -n 14 > /sys/class/backlight/mbp_backlight/brightness;
;;
13)
echo -n 13 > /sys/class/backlight/mbp_backlight/brightness;
;;
12)
echo -n 12 > /sys/class/backlight/mbp_backlight/brightness;
;;
11)
echo -n 11 > /sys/class/backlight/mbp_backlight/brightness;
;;
10)
echo -n 10 > /sys/class/backlight/mbp_backlight/brightness;
;;
9)
echo -n 9 > /sys/class/backlight/mbp_backlight/brightness;
;;
8)
echo -n 8 > /sys/class/backlight/mbp_backlight/brightness;
;;
7)
echo -n 7 > /sys/class/backlight/mbp_backlight/brightness;
;;
6)
echo -n 6 > /sys/class/backlight/mbp_backlight/brightness;
;;
5)
echo -n 5 > /sys/class/backlight/mbp_backlight/brightness;
;;
4)
echo -n 4 > /sys/class/backlight/mbp_backlight/brightness;
;;
3)
echo -n 3 > /sys/class/backlight/mbp_backlight/brightness;
;;
3)
echo -n 2 > /sys/class/backlight/mbp_backlight/brightness;
;;
1)
echo -n 1 > /sys/class/backlight/mbp_backlight/brightness;
;;
*)
echo -n 15 > /sys/class/backlight/mbp_backlight/brightness ;
;;
esac

#!/bin/bash

CURRENT=`cat /sys/class/backlight/mbp_backlight/actual_brightness`


case "$CURRENT" in

1)
echo -n 1 > /sys/class/backlight/mbp_backlight/brightness;
;;
2)
echo -n 2 > /sys/class/backlight/mbp_backlight/brightness;
;;
3)
echo -n 3 > /sys/class/backlight/mbp_backlight/brightness;
;;
4)
echo -n 4 > /sys/class/backlight/mbp_backlight/brightness;
;;
5)
echo -n 5 > /sys/class/backlight/mbp_backlight/brightness;
;;
6)
echo -n 6 > /sys/class/backlight/mbp_backlight/brightness;
;;
7)
echo -n 7 > /sys/class/backlight/mbp_backlight/brightness;
;;
8)
echo -n 8 > /sys/class/backlight/mbp_backlight/brightness;
;;
9)
echo -n 9 > /sys/class/backlight/mbp_backlight/brightness;
;;
10)
echo -n 10 > /sys/class/backlight/mbp_backlight/brightness;
;;
11)
echo -n 11 > /sys/class/backlight/mbp_backlight/brightness;
;;
12)
echo -n 12 > /sys/class/backlight/mbp_backlight/brightness;
;;
13)
echo -n 13 > /sys/class/backlight/mbp_backlight/brightness;
;;
14)
echo -n 14 > /sys/class/backlight/mbp_backlight/brightness;
;;
15)
echo -n 15 > /sys/class/backlight/mbp_backlight/brightness;
;;
*)
echo -n 7 > /sys/class/backlight/mbp_backlight/brightness ;
;;
esac

[Mahalingam]

Well you should boot your computer without loading mbp_nvidia_bl module which is located at /etc/modules.

sudo modprobe mbp_nvidia_bl debug=1
Nov 24 02:15:16 vertical kernel: [   87.852919] mbp_nvidia_bl: MacBookPro 5,1 detected
Nov 24 02:15:16 vertical kernel: [   87.853376] mbp_nvidia_bl: read brightness of 15
Nov 24 02:15:16 vertical kernel: [   87.853460] mbp_nvidia_bl: setting brightness to 15

After doing that tried to adjust brightness level manually

sudo su
echo 8 > /sys/class/backlight/mbp_backlight/brightness
Nov 24 02:15:38 vertical kernel: [  109.240574] mbp_nvidia_bl: setting brightness to 8

[Donatien]

I noticed that screen of the laptop was getting darken after returning to suspend mode. I found that issue was associated with ambient auto-adjust. In order to disable the same you have to run below mentioned code.

gconftool-2 --type bool --set /apps/gnome-power-manager/ambient/enable false

[Aachman]

You can give a try to below mentioned steps.

You have to see that hal addon is loading.

sed 's/mbp_nvidia_bl/applesmc/' /usr/share/hal/fdi/policy/10osvendor/10-nvidia-bl.fdi | sudo tee /etc/hal/fdi/policy/nvidia-testing.fdi

simply remove the backlight module

sudo rmmod mbp_nvidia_bl

you should restart HAL

sudo /etc/init.d/hal restart

you have to check for hal devices

hal-find-by-capability --capability laptop_panel

now start backlight module

sudo modprobe mbp_nvidia_bl

Restart X
If everything is seems to working fine than there should be /org/freedesktop/Hal/devices/nvidia_laptop_panel and brightness would work without any issue.
Now run below mentioned code.

sudo rm /etc/hal/fdi/policy/nvidia-testing.fdi

you should restart HAL and restart X to make the thing working normally.

[HamsiniI]

I recommend following steps to save and restore backlight level at the suspend and resume.

sudo gedit /etc/pm/sleep.d/55backlight

you have to copy following code in the script

#!/bin/sh

# Save & restore backlight level

. "${PM_FUNCTIONS}" || . "${FUNCTIONS}"

case "$1" in
	hibernate|suspend)
		HOME=/root /usr/local/bin/nvclock -i | grep Backlight | awk '{print $3}' > /root/.backlight
		;;
	thaw|resume)
		HOME=/root /usr/local/bin/nvclock -S `cat /root/.backlight`
		;;
	*) exit $NA
		;;
esac

now make the same executable

sudo chmod +x /etc/pm/sleep.d/55backlight