I am not able to “enable” the second external DELL U2327QE in Daisy Chain mode.
I do see the monitor in the “Display Configuration”, but every time I enable it and press “Apply”, the system freezes. This setup works with Windows 10 (Dual boot).
Here are some information about my setup:
SUMMARY
When trying to enable a second external monitor (both DELL U2327QE in Daisy Chain setup, which works on Window 10) freezes the system.
STEPS TO REPRODUCE
Open “Display Configuration”
Select second (not enabled Monitor) and “click Enable”
Click apply, this then freezes the system.
OBSERVED RESULT
System is freezing. Mouse etc. doesn’t work, only CTR-L + DEL brings it back (may finding).
EXPECTED RESULT
That the “enabling” of the second external Monitor (DELL U2327QE) will bring it to live.
I have attached a screenshot and some information about the system, I hope will be of help to you
SOFTWARE/OS VERSIONS
Windows:
macOS:
(available in the Info Center app, or by running kinfo in a terminal window)
Below what I found via “journalctl”, as I tried it to enable:
Jan 04 10:22:35 linux-9jdx systemd[2034]: Started Display Configuration.
Jan 04 10:22:35 linux-9jdx systemsettings[5456]: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8.
Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead.
If this causes problems, reconfigure your locale. See the locale(1) manual
for more information.
Jan 04 10:22:36 linux-9jdx systemsettings[5456]: Failed to register with host portal QDBusError("org.freedesktop.portal.Error.Failed", "Could not register app ID: Connection already associated with an application ID")
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:22:45 linux-9jdx kwin_wayland[2104]: Atomic modeset test failed! No space left on device
Jan 04 10:23:28 linux-9jdx systemd[1]: Starting Cleanup of Temporary Directories...
Jan 04 10:23:29 linux-9jdx systemd[1]: systemd-tmpfiles-clean.service: Deactivated successfully.
Jan 04 10:23:29 linux-9jdx systemd[1]: Finished Cleanup of Temporary Directories.
and a screenshot, where one can see the second screen I tried to “enable”:
Your log shows several out of space errors “No space left on device.” I would fix this before anything else. Also, is there anything relevant in dmesg?
Ok, thanks to this KDE discussion: “compositor-freezes-when-plugging-in-a-particular-screen”, can’t include links.
I managed to enable the second external DELL U2327QE, but with a lower resolution 1920 x 1080. So, that means that there may be a buffer size issue (guessing).
Not sure, if this is a bug and should be reported, as the normal resolution would be 3840 x 2160.
