Thanks. That indeed confirms the 99.98Hz mode has suddenly gone missing
in the last attachment. The system seems to be treating that as a
different monitor configuration and will revert to defaults (which is
landscape and 59.97Hz).
When this happens though, the monitor's EDID does not change. It still
reports the 99.98Hz mode exists:
Detailed mode: Clock 543.500 MHz, 797 mm x 333 mm
3440 3488 3520 3600 ( 48 32 80)
1440 1443 1453 1510 ( 3 10 57)
+hsync -vsync
VertFreq: 99.982 Hz, HorFreq: 150.972 kHz
So if the mode exists but is not offered as an option then that suggests
the kernel or driver thinks there's not enough bandwidth or a good
enough connection to support that particular mode. Therefore, please try
a different monitor cable.
** Summary changed:
- Display orientation resets on reboot with USB-C (DisplayPort) external
monitor and refresh rate dropdown disappears when setting it sometimes
+ 99.98Hz display mode is sometimes missing on USB-C (DisplayPort) external
monitor, which resets the display layout
** Package changed: gnome-shell (Ubuntu) => linux (Ubuntu)
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1922540
Title:
99.98Hz display mode is sometimes missing on USB-C (DisplayPort)
external monitor, which resets the display layout
Status in linux package in Ubuntu:
Incomplete
Bug description:
When rebooting with USB-C external monitor (3440x1440) attached,
display orientation in "gnome-control-center display" resets requiring
one to reposition the windows on boot. Very annoying.
In addition, refresh rate drop down for external display sometimes
goes missing when setting refresh rate to 100hz instead of default
60?Hz. Refresh rate listing and dropdown box disappears until setting
monitor resolution to different resolution and back or reboot.
ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: gnome-control-center 1:3.38.5-1ubuntu1
ProcVersionSignature: Ubuntu 5.11.0-13.14-generic 5.11.7
Uname: Linux 5.11.0-13-generic x86_64
ApportVersion: 2.20.11-0ubuntu61
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Mon Apr 5 01:09:38 2021
InstallationDate: Installed on 2021-04-05 (0 days ago)
InstallationMedia: Ubuntu 21.04 "Hirsute Hippo" - Beta amd64 (20210331.1)
ProcEnviron:
LANGUAGE=en_CA:en
PATH=(custom, no user)
XDG_RUNTIME_DIR=<set>
LANG=en_CA.UTF-8
SHELL=/bin/bash
SourcePackage: gnome-control-center
UpgradeStatus: No upgrade log present (probably fresh install)
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1922540/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
