systemd-backlight@backlight:acpi_video0.service failed

Here is my system info:

inxi -Fxz

System:    Host: Lucifer Kernel: 5.4.52-1-MANJARO x86_64 bits: 64 compiler: gcc v: 10.1.0 
           Desktop: KDE Plasma 5.19.3 Distro: Manjaro Linux 
Machine:   Type: Laptop System: Hewlett-Packard product: HP ZBook 15 G2 v: A3009DD10303 
           serial: <filter> 
           Mobo: Hewlett-Packard model: 2253 v: KBC Version 03.10 serial: <filter> 
           BIOS: Hewlett-Packard v: M70 Ver. 01.08 date: 03/16/2015 
Battery:   ID-1: BAT0 charge: 62.3 Wh condition: 62.3/62.3 Wh (100%) 
           model: Hewlett-Packard Primary status: Full 
CPU:       Topology: Quad Core model: Intel Core i7-4810MQ bits: 64 type: MT MCP 
           arch: Haswell rev: 3 L2 cache: 6144 KiB 
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 44716 
           Speed: 2212 MHz min/max: 800/3800 MHz Core speeds (MHz): 1: 2212 2: 1723 3: 1760 
           4: 1860 5: 2267 6: 2378 7: 1891 8: 2283 
Graphics:  Device-1: NVIDIA GK106GLM [Quadro K2100M] vendor: Hewlett-Packard 
           driver: nouveau v: kernel bus ID: 01:00.0 
           Display: x11 server: X.Org 1.20.8 driver: nouveau unloaded: modesetting 
           resolution: 1920x1080~60Hz 
           OpenGL: renderer: NVE6 v: 4.3 Mesa 20.1.3 direct render: Yes 
Audio:     Device-1: Intel 8 Series/C220 Series High Definition Audio 
           vendor: Hewlett-Packard driver: snd_hda_intel v: kernel bus ID: 00:1b.0 
           Device-2: NVIDIA GK106 HDMI Audio vendor: Hewlett-Packard driver: snd_hda_intel 
           v: kernel bus ID: 01:00.1 
           Sound Server: ALSA v: k5.4.52-1-MANJARO 
Network:   Device-1: Intel Ethernet I217-LM vendor: Hewlett-Packard driver: e1000e 
           v: 3.2.6-k port: 6040 bus ID: 00:19.0 
           IF: enp0s25 state: down mac: <filter> 
           Device-2: Intel Wireless 7260 driver: iwlwifi v: kernel port: 5000 
           bus ID: 3d:00.0 
           IF: wlp61s0 state: up mac: <filter> 
           Device-3: Huawei E353/E3131 type: USB driver: cdc_ether bus ID: 2-9:4 
           IF: enp0s20u9 state: unknown speed: N/A duplex: N/A mac: <filter> 
Drives:    Local Storage: total: 465.76 GiB used: 368.98 GiB (79.2%) 
           ID-1: /dev/sda vendor: Seagate model: ST500VT000-1DK142 size: 465.76 GiB 
Partition: ID-1: / size: 440.60 GiB used: 368.98 GiB (83.7%) fs: ext4 dev: /dev/sda1 
           ID-2: swap-1 size: 17.11 GiB used: 0 KiB (0.0%) fs: swap dev: /dev/sda2 
Sensors:   System Temperatures: cpu: 71.0 C mobo: N/A gpu: nouveau temp: 127 C 
           Fan Speeds (RPM): N/A 
Info:      Processes: 267 Uptime: 1h 56m Memory: 15.56 GiB used: 4.00 GiB (25.7%) 
           Init: systemd Compilers: gcc: 10.1.0 Shell: bash v: 5.0.18 inxi: 3.0.37 

systemd-analyze blame

20.045s systemd-journal-flush.service                                            
14.167s NetworkManager-wait-online.service                                       
12.129s lvm2-monitor.service                                                     
11.211s snapd.service                                                            
10.414s dev-sda1.device                                                          
 9.582s polkit.service                                                           
 5.167s ldconfig.service                                                         
 3.922s avahi-daemon.service                                                     
 3.920s bluetooth.service                                                        
 3.918s NetworkManager.service                                                   
 3.910s systemd-logind.service                                                   
 3.511s apparmor.service                                                         
 3.321s systemd-tmpfiles-clean.service                                           
 3.321s org.cups.cupsd.service                                                   
 2.953s systemd-udevd.service                                                    
 1.778s systemd-modules-load.service                                             
 1.733s ModemManager.service                                                     
 1.419s var-lib-snapd-snap-spotify-41.mount                                      
 1.317s systemd-sysusers.service                                                 
 1.277s snapd.apparmor.service                                                   
 1.185s systemd-tmpfiles-setup-dev.service                                       
 1.172s var-lib-snapd-snap-core-9436.mount                                       
 1.083s var-lib-snapd-snap-core-9665.mount                                       
  955ms var-lib-snapd-snap-core18-1880.mount                                     
  948ms udisks2.service                                                          
  933ms tlp.service                                                              
  901ms systemd-random-seed.service                                              
  820ms systemd-tmpfiles-setup.service                                           
  796ms dev-loop0.device                                                         
  699ms modprobe@drm.service                                                     
  674ms colord.service                                                           
  624ms systemd-journald.service                                                 
  571ms upower.service                                                           
  520ms wpa_supplicant.service                                                   
  488ms systemd-backlight@backlight:nv_backlight.service                         
  478ms systemd-sysctl.service                                                   
  473ms systemd-timesyncd.service                                                
  427ms kmod-static-nodes.service                                                
  400ms user@1000.service                                                        
  365ms ufw.service                                                              
  363ms rtkit-daemon.service                                                     
  348ms dev-disk-by\x2duuid-3eb95ec5\x2d6e14\x2d48e6\x2d812b\x2d1b73ff2d478e.swap
  346ms systemd-rfkill.service                                                   
  336ms dev-hugepages.mount                                                      
  335ms sys-kernel-debug.mount                                                   
  335ms dev-mqueue.mount                                                         
  335ms sys-kernel-tracing.mount                                                 
  283ms systemd-binfmt.service                                                   
  255ms systemd-journal-catalog-update.service                                   
  179ms systemd-udev-trigger.service                                             
  170ms systemd-update-utmp.service                                              
  118ms systemd-backlight@backlight:acpi_video0.service

systemd-analyze critical-chain

The time when unit became active or started is printed after the "@" character.
The time the unit took to start is printed after the "+" character. @49.514s
└─ @49.514s
  └─cups-browsed.service @49.514s
    └─org.cups.cupsd.service @46.190s +3.321s
      └─ @46.188s
        └─NetworkManager-wait-online.service @32.020s +14.167s
          └─NetworkManager.service @28.099s +3.918s
            └─dbus.service @28.097s
              └─ @28.093s
                └─ @28.092s
                  └─snapd.socket @28.091s +924us
                    └─ @28.044s
                      └─systemd-timesyncd.service @27.571s +473ms
                        └─systemd-tmpfiles-setup.service @26.643s +820ms
                          └─systemd-journal-flush.service @6.597s +20.045s
                            └─systemd-journald.service @5.964s +624ms
                              └─systemd-journald.socket @5.668s
                                └─-.mount @5.220s
                                  └─system.slice @5.220s
                                    └─-.slice @5.220s

sudo systemctl --failed

  UNIT                                            LOAD   ACTIVE SUB    DESCRIPTION                                                   
â—Ź systemd-backlight@backlight:acpi_video0.service loaded failed failed Load/Save Screen Backlight Brightness of backlight:acpi_video0

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

1 loaded units listed.

uname -a

Linux Lucifer 5.4.52-1-MANJARO #1 SMP PREEMPT Thu Jul 16 16:07:11 UTC 2020 x86_64 GNU/Linux

I Am Running Manjaro Linux KDE On An HP ZBook 15 G2

This Problem Is Haunting My Nights... Please Help Me Out

Try this solution
is also mentioned here

I recommend to go trough this too. Now you use the nouveau drivers, probably you can use the proprietary drivers and also have better performance.

Check if you have xbacklight installed. Try from terminal:
xbacklight -dec 10
xbacklight -inc 10
it they work, then you are good to go with the above.

It seems your system selects a different backlight service successfully (check its status to confirm).
If so, the error message is just cosmetic/info and it is safe to solve it just by masking the failing service (use systemd).

I somehow installed NVIDIA Drivers And my whole display ratio was completely wrong.

there was no way i could fix it. so i reinstalled manjaro again.

     Loaded: loaded (/usr/lib/systemd/system/systemd-backlight@.service; static; vendor preset: disabled)
     Active: failed (Result: exit-code) since Thu 2020-08-06 08:07:39 IST; 3h 6min ago
       Docs: man:systemd-backlight@.service(8)
   Main PID: 527 (code=exited, status=1/FAILURE)

Aug 06 08:07:39 bufferdot systemd[1]: Starting Load/Save Screen Backlight Brightness of backlight:acpi_video0...
Aug 06 08:07:39 bufferdot systemd[1]: systemd-backlight@backlight:acpi_video0.service: Main process exited, code=exited, status=1/FAILURE
Aug 06 08:07:39 bufferdot systemd[1]: systemd-backlight@backlight:acpi_video0.service: Failed with result 'exit-code'.
Aug 06 08:07:39 bufferdot systemd[1]: Failed to start Load/Save Screen Backlight Brightness of backlight:acpi_video0.

[quote="bogdancovaciu, post:2, topic:154728"]

These Are deb files right ....
how to install themm??

xorg-xbacklight is a package in repository
sudo pacman -Syu xorg-xbacklight
Once installed you can make use of the xbacklight commands as per those examples, depending on what driver you use for GPU.


> [test@bufferdot ~]$  xbacklight -dec 10
> No outputs have backlight property
> [test@bufferdot ~]$  xbacklight -inc 10
> No outputs have backlight property``

Some laptops require one of these kernel parameters:

acpi_osi="!Windows 2012"

or as described here

Check from terminal:
ls /sys/class/backlight/

Then maybe this might give more information to get it working


[test@bufferdot ~]$ ls /sys/class/backlight/

Check this out
So you actually don't need xbacklight but rather light

Apart from the message, what about actual functionality?
Do buttons or other means work on Display backlight?

systemctl status systemd-backlight@backlight:nv_backlight.service
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Yaa The Function And Brightness Button works....

it does reduce my brightness

Then mask the failing one. It does not exist.
Error messages are info/cosmetic.

1 Like

can u tell me how to do it in a bit more detail

Manual systemctl

systemctl mask systemd-backlight@backlight:acpi_video0.service
1 Like


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