[media-keys] GNOME hangs while changing display brightness from keyboard shortcut

[Sujit Kumar]

Whenever I change my display's brightness using keyboard shortcuts (For me F11 & F12), Ubuntu hangs a little, the brightness is changed immediately, but everything (except the mouse) hangs while it is being changed and sometimes for quite some time after. There is no problem doing it through the system. Changing volume using keyboard shortcuts works perfectly.
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ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu27.8
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
DisplayManager: gdm3
DistroRelease: Ubuntu 20.04
InstallationDate: Installed on 2020-08-22 (3 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
NonfreeKernelModules: nvidia
Package: gnome-shell 3.36.4-1ubuntu1~20.04.2
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
RelatedPackageVersions: mutter-common 3.36.4-0ubuntu0.20.04.2
Tags: focal
Uname: Linux 5.4.0-42-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin lxd plugdev sambashare sudo
_MarkForUpload: True

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1892747/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Daniel van Vugt (vanvugt)]

You're probably not using 'gnome-shell-extension-brightness-control'. Please run this command to send us more information about the system:

  apport-collect 1892747

[Sujit Kumar (therealsujitk)]

apport information

[Sujit Kumar (therealsujitk)]

apport information

[Sujit Kumar (therealsujitk)]

apport information

[Sujit Kumar (therealsujitk)]

apport information

[Sujit Kumar (therealsujitk)]

apport information

[Sujit Kumar (therealsujitk)]

apport information

[Sujit Kumar (therealsujitk)]

Daniel, I ran the command and clicked "Send Report".

[Daniel van Vugt (vanvugt)]

I can see bug 1849142 is also happening in your logs. Please try disabling 'Ubuntu AppIndicators' in the 'Extensions' app, and then tell us if this bug still happens.

[Sujit Kumar (therealsujitk)]

Daniel, the bug s still present after running
    gnome-extensions disable <email address hidden>

[Sujit Kumar (therealsujitk)]

I found this question on askUbuntu: https://askubuntu.com/questions/1242205/ubuntu-20-04-hangs-when-changing-brightness-level-with-keyboard . Someone else is also facing the same bug. Does this mean the bug can be Confirmed now?

[Sujit Kumar (therealsujitk)]

Daniel, I'm not sure if this bug is related but, the system also hangs for a few seconds whenever the Wi-Fi gets disconnected.

[Daniel van Vugt (vanvugt)]

Bugs like this are model-specific. And since the above link is about a different model of laptop, this bug is not yet confirmed. It's still open and valid, so don't worry.

[Daniel van Vugt (vanvugt)]

It seems I was wrong. More bug reports found, and tracking upstream in:

https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/1279

[Cristiano Fraga G. Nunes (cfgnunes)]

Adding more information:

Similar bug:
https://bugs.launchpad.net/ubuntu/+source/xkeyboard-config/+bug/1895486

For ABNT2 keyboards, I've removed the "Scroll Lock" key to fix this problem, see:
https://gitlab.freedesktop.org/xkeyboard-config/xkeyboard-config/-/merge_requests/112

Bug tracking in:
https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/1821

[Sujit Kumar (therealsujitk)]

I should add, I'm using Ubuntu 22.04 now and I don't face the issue anymore. In 22.04 I use the Wayland windowing system, so I no longer use nvidia drivers, not sure if the problem lies there.

[Daniel van Vugt (vanvugt)]

Alright then we'll close this and keep bug 2013255 open.

[Cristiano Fraga G. Nunes (cfgnunes)]

Just for better bug tracking, I've added some links.

Launchpad related bugs (maybe duplicated):
- https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/2013255
- https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1892747
- https://bugs.launchpad.net/gnome-shell/+bug/1895486

This bug appears on AskUbuntu:
- https://askubuntu.com/questions/1242205/ubuntu-20-04-hangs-when-changing-brightness-level-with-keyboard
- https://askubuntu.com/questions/1278008/huge-lag-and-screen-freezes-changing-the-brightness-on-ubuntu-20-04-using-the-ho
- https://askubuntu.com/questions/1065302/volume-and-brighness-adjustment-osd-delay-and-screen-freeze-on-ubuntu-18-04
- https://askubuntu.com/questions/1041335/ubuntu-18-04-input-slow-when-portuguese-brazil-layout-among-keyboard-input-sou
- https://askubuntu.com/questions/1130163/laggy-brightness-control-on-dell-inspirion-using-function-keys-ubuntu-18-04
- https://askubuntu.com/questions/1025302/media-keys-delayed-and-cause-a-cpu-spike-to-100-on-ubuntu-17-10-with-gnome
- https://askubuntu.com/questions/906723/fn-media-keys-slow-delayed-on-ubuntu-gnome-17-04

Upstream issues:
- https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/1821
- https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/1279