[Dell Precision 7720] Unable to change brightness on this I+A laptop

[Po-Hsu Lin]

When you press the hotkey to adjust the screen brightness, the brightness level indicator will change accordingly, but the actual brightness does not.

And from watching the brightness file in /sys/class/backlight/amdgpu_bl0, when the brightness control hotkey was pressed, it will change the value here (1~255).

$ ls /sys/class/backlight/
amdgpu_bl0 intel_backlight

This issue existed since 16.04.2 + 4.8 HWE kernel.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.10.0-27-generic 4.10.0-27.30~16.04.2
ProcVersionSignature: Ubuntu 4.10.0-27.30~16.04.2-generic 4.10.17
Uname: Linux 4.10.0-27-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.9
Architecture: amd64
Date: Thu Jul 6 06:37:41 2017
InstallationDate: Installed on 2017-07-06 (0 days ago)
InstallationMedia: Ubuntu 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170209)
SourcePackage: linux-hwe
UpgradeStatus: No upgrade log present (probably fresh install)

[Kai-Heng Feng (kaihengfeng)]

This should be fixed in latest gnome-settings-daemon.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1702666

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]