Backlight Permission Denied i3

aris997 · 2020-03-09 12:20:28

Hi everyone,
I have a Xiami Mi Book Pro 15.6, Host: TM1701, kernel 5.5.8-arch1-1
I'm setting up i3 and all the key binding. The first time I installed arch-i3 I find out a way to change the brightness using a script I wrote by my self that I called every time I pressed the brightness buttons. (As I was following the tips from the wiki arch page: https://wiki.archlinux.org/index.php/Xi … k_Pro_15.6).

#!/bin/env bash
actual_bright=$(cat /sys/class/backlight/intel_backlight/brightness)
echo $((actual_bright - 75)) > /sys/class/backlight/intel_backlight/brightness

#!/bin/env bash
actual_bright=$(cat /sys/class/backlight/intel_backlight/brightness)
echo $((actual_bright + 75)) > /sys/class/backlight/intel_backlight/brightness

This worked in my first installation pretty well.
Now I'm working on the second installation (I've done a cleaner one that feels faster than the first one) and now setting the same way these scripts don't work because of Permission Denied. I would like an easier way, or I could give permission to these scripts in some way. I would like a package (please tell me which one).

I also tried to config via this file: /etc/X11/xorg.conf.d/10-backlight.conf as shown in the wiki page as follow:

Section "Device" 
        Identifier "Card0" 
        Driver     "intel" 
        Option     "Backlight"  "intel_backlight" 
        BusID      "PCI:0:2:0" 
EndSection

but this really don't work at all, xorg wouldn't start.

Please tell me if I've to give permission to run a shell script or there is a package that works on my laptop

seth · 2020-03-09 13:53:17

No and no.
But you can alter the permissions of the file you're trying to write into as is suggested in the wiki: https://wiki.archlinux.org/index.php/Backlight#ACPI

aris997 · 2020-03-09 16:35:41

I'm trying to follow the link you sended me, my graphic card is intel_backlight (so I've replaced acpi_video0 with inte_backlight), but I can't change group, I've also setted rules about udev and they don't seems to work. Where is the mistake?

seth · 2020-03-09 16:56:18

"You did it wrong™."

…

I cannot tell you where the mistake is unless you detail what you actually and *exactly* did.

Right off the bat:
- the video group needs to exist and you want to be a member, https://wiki.archlinux.org/index.php/Us … management
- "inte_backlight", the system will not allow for typos.
- you'll have to reload the udev rules and make the device re-appear, https://wiki.archlinux.org/index.php/Udev - in doubt just reboot.

aris997 · 2020-03-09 17:02:00

You are right, there was no video group!

Thanks a lot and sorry for the newbie question

loqs · 2020-03-09 17:34:02

aris997 wrote:

You are right, there was no video group!

/usr/lib/sysusers.d/basic.conf line 35 provided by systemd 244.3-1

g video   -     -            -

Is sysusers broken on your system?

Arch Linux

#1 2020-03-09 12:20:28

Backlight Permission Denied i3

#2 2020-03-09 13:53:17

Re: Backlight Permission Denied i3

#3 2020-03-09 16:35:41

Re: Backlight Permission Denied i3

#4 2020-03-09 16:56:18

Re: Backlight Permission Denied i3

#5 2020-03-09 17:02:00

Re: Backlight Permission Denied i3

#6 2020-03-09 17:34:02

Re: Backlight Permission Denied i3

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