6

loving the new OS. Just installed Loki today and have a problem with screen brightness. My screen is at full brightness, which is a pain at night.

I have a MacBook Pro late 2013 11,3 with dual nvidia, intel graphics

Some steps I've attempted.

SYSTEM SETTINGS > POWER > DISPLAY BRIGHTNESS doesn't seem to do anything.

I ran ls /sys/class/backlight and got a returned result of gmux_backlight

I also attempted adding setpci -v -H1 -s 00:01.00 BRIDGE_CONTROL etc=0 to etc/local.rc based on another question & response here. But even after reboot, still no luck.

Anyone have any trouble shooting ideas?

One thing, I did not check install 3rd party drivers at setup. Is that part of the problem?

Thanks

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1
  • Not work with intel graphic card Here is lspci output lspci 00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09) 00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) 00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04) 00:16.3 Serial controller: Intel Corporation 6 Series/C200 Series Chipset Family KT Controller (rev 04) 00:19.0 Ethernet controller: Intel Corporation 82579LM Gigabit Network Connection (rev 04)
    – Sand Angel
    Dec 21, 2016 at 13:45

3 Answers 3

Reset to default
2

I found that after running setpci I needed to reload the apple_gmux module, so my /etc/rc.local looks like this:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

setpci -v -H1 -s 00:01.00 BRIDGE_CONTROL=0
modprobe -r apple_gmux
modprobe apple_gmux

exit 0
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2
  • 1
    This worked for me on my 2015 MBPR 15", thanks!!
    – horseyguy
    Jan 7, 2018 at 19:57
  • I'm so glad it helped :-)
    – Brad Pitcher
    Jan 8, 2018 at 21:45
1

This code works for me, same might help you.. give a try!

sudo apt install xbacklight

then run 

xbacklight -set 15

15 is the percentage of backlight you gonna use. You can change any percentage value according to your need.

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0

There is a typo in your command. This is the correct one:

setpci -v -H1 -s 00:01.00 BRIDGE_CONTROL=0

First of all execute it in any terminal app and then try to change the brightness pressing F1/F2 keys. Add this line to your rc.local only if it works.

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