Black screen when booting with display off (SDDM)

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1

I am running KDE on Fedora on a desktop with a discrete AMD GPU.

Since a few months, the SDDM login screen does not appear whenever the display is turned on after the system has booted. I can switch to a terminal with CTRL+ALT+F-key

Fedora Workstation (GNOME) is not affected by the issue, nor is OpenSUSE Tumbleweed with KDE. I was about to think this may be a Fedora-specific issue, but from the logs I noticed that Fedora seems to run SDDM using Wayland while OpenSUSE does not.

I have tried to compare the systemd logs in the two scenarios (screen on vs off at boot). The main obvious difference is that with the screen off I get:

:20 sddm-greeter[1411]: Creating a fake screen in order for Qt not to crash
:20 sddm-helper-start-wayland[1408]: “qt.qpa.wayland: Creating a fake screen in order for Qt not to crash\n”
:20 sddm-greeter[1411]: Loading file:///usr/share/sddm/themes/breeze/Main.qml…
:20 sddm-greeter[1411]: QQmlEngine::setContextForObject(): Object already has a QQmlContext
:20 sddm-greeter[1411]: QQmlEngine::setContextForObject(): Object already has a QQmlContext
:20 sddm-greeter[1411]: Failed to find a Kirigami platform plugin
:21 sddm-greeter[1411]: Creating a layer shell for placeholder screen. This will be positioned incorrectly
:21 sddm-greeter[1411]: Wayland does not support QWindow::requestActivate()
:21 sddm-greeter[1411]: Wayland does not support QWindow::requestActivate()
:21 audit[1432]: ANOM_ABEND auid=4294967295 uid=983 gid=976 ses=4294967295 subj=system_u:system_r:xdm_t:s0-s0:c0.c1023 pid=1432 comm=“QSGRenderThread” exe=“/usr/bin/maliit-keyboard” sig=11 res=1

Following a segfault and core dump of maliit-keyboard. This seems to go on a couple of times until:

sddm-helper-start-wayland[1408]: “warning: queue 0x55d0c7867590 destroyed while proxies still attached:\n wl_display@1 still attached\n”
sddm-helper-start-wayland[1408]: Stopping… “kwin_wayland”

I have searched for similar issues but they mostly involve laptops with external displays and/or Nvidia graphics, not my case. And no open SDDM issue seem to match mine.

Anything specific I should look for in the logs? Should I report this to Fedora or SDDM?

Thanks in advance for any suggestion.

EDIT: probably it is not relevant, but I normally use KDE on X11 (although SDDM runs on Wayland by default, apparently).

2

That reminds me of: Freezes at login when using X11 after installing Maliit Keyboard

I doubt it is the same issue, but just to be sure try uninstalling mallit.

I would ask the Fedora people. They will know if should report this to the SDDM Bug tracker or if this is a Fedora issue.

3

Not possible. Mallit is a dependency for SDDM.

4

I have filed a bug to Fedora.

Thank you for the advice!

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