[SOLVED] Laptop monitor brightness option not detected

riccardooo97 · 2019-08-27 02:10:27

Hi.
I recently installed i3 on my PC.
I can't configure functions key to use the brightness function as, when i run "xbacklight -inc 20", i get an error: No outputs have backlight property
So i found here a possible solution.
The only problem is the output of the command..

sudo find /sys/ -type f -iname '*brightness*'
[sudo] password for riccardo:

/sys/devices/platform/i8042/serio0/input/input4/input4::capslock/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::capslock/max_brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::scrolllock/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::scrolllock/max_brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::numlock/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::numlock/max_brightness
/sys/devices/platform/dell-laptop/leds/dell::kbd_backlight/brightness
/sys/devices/platform/dell-laptop/leds/dell::kbd_backlight/brightness_hw_changed
/sys/devices/platform/dell-laptop/leds/dell::kbd_backlight/max_brightness
/sys/devices/platform/dell-laptop/leds/platform::micmute/brightness
/sys/devices/platform/dell-laptop/leds/platform::micmute/max_brightness
/sys/devices/pci0000:00/0000:00:1c.0/0000:01:00.0/leds/phy0-led/brightness
/sys/devices/pci0000:00/0000:00:1c.0/0000:01:00.0/leds/phy0-led/max_brightness
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight/actual_brightness
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight/brightness
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight/max_brightness
/sys/module/video/parameters/brightness_switch_enabled
/sys/module/i915/parameters/invert_brightness

The device found is "eDP-1" which stands for "external display ?", instead of "DP-1".
I am sure of that because i use eDP-1 when i run xrandr when connecting external monitors.
So basically it doesn't recognize the monitor as a possible source to change brightness level.
If i setup a xorg.conf file as indicated in the post, xorg crashes badly.
I'm stuck and don't know what to do. Any idea?

EDIT

Followed the first method described here.
Now i have more output with: sudo find /sys/ -type f -iname '*brightness*'

/sys/devices/platform/dell-laptop/backlight/dell_backlight/actual_brightness
/sys/devices/platform/dell-laptop/backlight/dell_backlight/brightness
/sys/devices/platform/dell-laptop/backlight/dell_backlight/max_brightness

I'll try and update.

EDIT 2

Nope. It doesn't work.

In /sys/class/backlight i have two file now..
dell_backlight
intel_backlight

But still the same error message:
xbacklight -inc 10
No outputs have backlight property

I tired with the /etc/X11/xorg.conf file, configured with:
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "Backlight" "dell_backlight"
EndSection

Xorg still crashes.
Really don't know what to do

Last edited by riccardooo97 (2019-08-27 12:41:41)

seth · 2019-08-27 07:20:34

https://wiki.archlinux.org/index.php/Ba … i915_only)

riccardooo97 · 2019-08-27 09:09:11

So sorry about that. e-DP1 was for "embedded display port"
However it still doesn't work.
My grub config now has:
GRUB_CMDLINE_LINUX_DEFAULT="quiet i915.enable_dpcd_backlight=1 acpi_backlight=vendor"

Always "No outputs have backlight property"
I tried again with xorg.conf and still get crash on startx.

Last edited by riccardooo97 (2019-08-27 09:09:23)

seth · 2019-08-27 10:32:40

See https://wiki.archlinux.org/index.php/Backlight#ACPI - can you access the backlight on /sys/class/backlight/ ?

riccardooo97 · 2019-08-27 12:41:12

It now works changing the backlight file!
I tried yesterday at the beginning. I think it was the two missing command in /etc/default/grub.
However, xorg-xbacklight still don't works. So i tried acpilight, which I found in the arch wiki page you sent on the last reply.
And it finally works! Don't know if it is incompatibility or whatever, but now it works.
Thanks a lot!

Arch Linux

#1 2019-08-27 02:10:27

[SOLVED] Laptop monitor brightness option not detected

#2 2019-08-27 07:20:34

Re: [SOLVED] Laptop monitor brightness option not detected

#3 2019-08-27 09:09:11

Re: [SOLVED] Laptop monitor brightness option not detected

#4 2019-08-27 10:32:40

Re: [SOLVED] Laptop monitor brightness option not detected

#5 2019-08-27 12:41:12

Re: [SOLVED] Laptop monitor brightness option not detected

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