Comment 0 for bug 1837117

After kernel update the backlight on my Asus eeepc 1005px becomes off during boot up. I can see the login screen if I point light to the screen. The backlight is not reacting on brightness adjustment keys. The backlight starts working only if I close and open the laptop lid.

I have tried to:
* echo 10 > /sys/class/backlight/acpi_video0/brightness
* echo 125 > /sys/class/backlight/intel_backlight/brightness
* vbetool dpms on
* pass "acpi_backlight=vendor" kernel parameter
* install gdm instead of lightdm
* create /usr/share/X11/xorg.conf.d/80-backlight.conf with content recommended in Kernel/Debugging/Backlight Wiki article
with no luck.

The backlight works fine if I pass "acpi_osi=" kernel parameter, the brightness is adjusted by keys, but the applet does not react to adjustments.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-145-generic 4.4.0-145.171
ProcVersionSignature: Ubuntu 4.4.0-145.171-generic 4.4.176
Uname: Linux 4.4.0-145-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
CurrentDesktop: XFCE
Date: Thu Jul 18 22:30:44 2019
InstallationDate: Installed on 2019-02-17 (151 days ago)
InstallationMedia: Xubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
SourcePackage: linux-signed
UpgradeStatus: No upgrade log present (probably fresh install)