#843693 sddm: starting sddm results in white screen with active cursor and keyboard

Package:
sddm
Source:
sddm
Description:
modern display manager for X11
Submitter:
Jape Person
Date:
2025-07-24 16:19:02 UTC
Severity:
important
#843693#5
Date:
2016-11-08 19:39:12 UTC
From:
To:
Dear Maintainer,

   * What led up to the situation?

Installed task-lxqt-desktop. Replacement of lightdm by sddm resulted in inability
to log in. Screen presented is all white, but cursor is visible, and keyboard
functions appear to be intact.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

Reconfigured to use lightdm and was able to log in to the system. Removed lightdm,
installed xdm, and that was also successful for logging in.

   * What was the outcome of this action?

Have left system temporarily configured to use xdm until sddm is fixed.

#843693#10
Date:
2016-11-08 22:48:50 UTC
From:
To:
¡Hola Jape!

El 2016-11-08 a las 14:39 -0500, Jape Person escribió:

The breeze theme causes sddm to use the composite mode, this has caused issues
with certain graphical cards in the past. Could you try installing
sddm-theme-maui and removing sddm-theme-breeze?

Also, could you share the output of:
 lspci -vnn | grep VGA -A 12

Happy hacking,

#843693#17
Date:
2016-11-13 18:57:07 UTC
From:
To:
Sincere apologies for not sending this properly before. I thought I
received an acknowledgment from the bug system, but I must have sent
only to Maximiliano.

Forgive the delay in sending this information properly.
-------- Forwarded Message -------- Subject: Re: Bug#843693: sddm: starting sddm results in white screen with active cursor and keyboard Date: Tue, 8 Nov 2016 20:09:50 -0500 Hello, Maximiliano! # lspci -vnn | grep VGA -A 12 01:00.0 VGA compatible controller [0300]: NVIDIA Corporation NV17 [GeForce4 MX 440] [10de:0171] (rev a3) (prog-if 00 [VGA controller]) Subsystem: ASUSTeK Computer Inc. NV17 [GeForce4 MX 440] [1043:a000] Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 16 Memory at e7000000 (32-bit, non-prefetchable) [size=16M] Memory at f0000000 (32-bit, prefetchable) [size=128M] Memory at ef800000 (32-bit, prefetchable) [size=512K] Expansion ROM at 000c0000 [disabled] [size=128K] Capabilities: [60] Power Management version 2 Capabilities: [44] AGP version 2.0 Kernel driver in use: nouveau Kernel modules: nouveau I did use apt to install sddm-theme-maui 0.13.0-1 and to purge sddm-theme-breeze. I used dpkg-reconfigure to switch from xdm back to sddm, but I still am getting a white screen. Mouse cursor is present and reacts to mouse movement, and keyboard is functional (can be used to cycle through virtual terminals). Other systems here are not having this trouble with sddm, so I can certainly believe that the old nvidia card is the source of the trouble. Please let me know if I can provide any more information. Best regards, Jape
#843693#22
Date:
2016-11-15 09:20:46 UTC
From:
To:
¡Hola Jape!

El 2016-11-13 a las 13:57 -0500, Jape Person escribió:

I had received your previous mail, I just haven't had the time to think about
this.

Ok, this is just a random guess as I don't have the hardware to test this.
But it might be that sddm is using opengl 2.0 calls and the geforce4 is as an
opengl 1.2 only video card (https://nouveau.freedesktop.org/wiki/CodeNames/)

This might be workaroundable using the swrast mesa backend (with some
associated performance penalties, though). For this you'll need to add
LIBGL_ALWAYS_SOFTWARE=1 to the sddm running environment.

Also, if you have a mix of video drivers (if you have some nvidia or nvidia
legacy parts installed) it might be that your glcore is being
replaced by the nvidia one. If that's the case, and as the lspci shows that you
are using the nouveau kernel driver the gl backend wouldn't work. For this
running:
 dpkg -l | grep nvidia
might help you to detect some half installed nvidia components.

Maybe someone in the #nouveau (irc.debian.org) irc channel might know better
how to debug/fix/workaround the issue.

That's on the video driver side of things, on the sddm side of things, the
corresponding syslog information for a sddm start might provide some insights.
And if the sddm-greeter is segfaulting, the corresponding backtrace might be
useful.

Happy hacking,

#843693#27
Date:
2019-07-09 12:29:49 UTC
From:
To:
Hello

After upgrade from stretch to buster, sddm failed to start.

There was a black screen with a mouse cursor.

All that was logged was that it failed to start.

lightdm works. I plan to use lightdm, but hope that this information is
useful to someone else.

lspci -vnn | grep VGA -A 12
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GM107GL
[Quadro K620] [10de:13bb] (rev a2) (prog-if 00 [VGA controller])
         Subsystem: Hewlett-Packard Company GM107GL [Quadro K620]
[103c:1098]
         Flags: bus master, fast devsel, latency 0, IRQ 127
         Memory at d2000000 (32-bit, non-prefetchable) [size=16M]
         Memory at c0000000 (64-bit, prefetchable) [size=256M]
         Memory at d0000000 (64-bit, prefetchable) [size=32M]
         I/O ports at 3000 [size=128]
         [virtual] Expansion ROM at 000c0000 [disabled] [size=128K]
         Capabilities: [60] Power Management version 3
         Capabilities: [68] MSI: Enable+ Count=1/1 Maskable- 64bit+
         Capabilities: [78] Express Legacy Endpoint, MSI 00
         Capabilities: [100] Virtual Channel
         Capabilities: [250] Latency Tolerance Reporting

01:00.1 Audio device [0403]: NVIDIA Corporation Device [10de:0fbc] (rev a1)

lsmod | egrep nvidia
nvidia_drm             49152  8
drm_kms_helper        200704  1 nvidia_drm
drm                   483328  11 drm_kms_helper,nvidia_drm
nvidia_modeset       1097728  22 nvidia_drm
nvidia              17936384  959 nvidia_modeset
ipmi_msghandler        65536  2 ipmi_devintf,nvidia

#843693#32
Date:
2020-05-20 13:19:07 UTC
From:
To:
-- 

Hello

hope you are doing great. my name is Gabriel. We can be friends
I have important information I would like to share with you

Have a great day

#843693#37
Date:
2024-12-23 21:14:31 UTC
From:
To:
Hello sddm maintainer,
I used sddm since before bookworm was released. A few days ago, the
previous sddm screen disappeared and instead the screen was all white.
I can enter my login name and password, but all other fields (like DE
selction, shutdown etc.) are not visible. If I hover around with the
mouse I might hit them by chance, so they are still existing (but
white on white).

Following #843693 I installed sddm-theme-maui and removed
sddm-theme-breeze (which also removed the Debian variant).

Now I can read everything again, but the sddm prompt is not very nice.

With breeze, I see the following in my logs:
2024-12-23T19:20:21.053183+01:00 twentytwo sddm-greeter-qt6[2705]: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/style.qml:1145:22: QML QQuickImage: Error decoding: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/images/selectionhandle-bottom.svg: Unsupported image format
2024-12-23T19:20:21.053295+01:00 twentytwo sddm-greeter-qt6[2705]: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/style.qml:1145:22: QML QQuickImage: Error decoding: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/images/selectionhandle-bottom.svg: Unsupported image format
2024-12-23T19:20:21.054965+01:00 twentytwo sddm-greeter-qt6[2705]: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/style.qml:1145:22: QML QQuickImage: Error decoding: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/images/selectionhandle-bottom.svg: Unsupported image format
2024-12-23T19:20:21.055356+01:00 twentytwo sddm-greeter-qt6[2705]: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/style.qml:1145:22: QML QQuickImage: Error decoding: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/images/selectionhandle-bottom.svg: Unsupported image format
2024-12-23T19:20:21.097402+01:00 twentytwo sddm-greeter-qt6[2705]: file:///usr/share/sddm/themes/breeze/Background.qml:21:5: QML QQuickImage: Error decoding: file:///usr/share/desktop-base/active-theme/login/background.svg: Unsupported image format
2024-12-23T19:20:21.104936+01:00 twentytwo sddm-greeter-qt6[2705]: Adding view for "DVI-D-0" QRect(0,0 1920x1200)
2024-12-23T19:20:21.312730+01:00 twentytwo sddm-greeter-qt6[2705]: file:///usr/share/sddm/themes/debian-theme/Main.qml:393:9: QML QQuickImage*: Error decoding: file:///usr/share/desktop-base/debian-logos/logo-text.svg: Unsupported image format
2024-12-23T19:20:21.320001+01:00 twentytwo sddm-greeter-qt6[2705]: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/style.qml:259:13: QML QQuickImage*: Error decoding: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/images/enter-fff.svg: Unsupported image format
2024-12-23T19:20:21.320158+01:00 twentytwo sddm-greeter-qt6[2705]: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/style.qml:355:13: QML QQuickImage: Error decoding: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/images/hidekeyboard-fff.svg: Unsupported image format
2024-12-23T19:20:21.331100+01:00 twentytwo sddm-greeter-qt6[2705]: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/style.qml:215:13: QML QQuickImage: Error decoding: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/images/globe-fff.svg: Unsupported image format
2024-12-23T19:20:21.331602+01:00 twentytwo sddm-greeter-qt6[2705]: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/style.qml:171:13: QML QQuickImage: Error decoding: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/images/backspace-fff.svg: Unsupported image format
2024-12-23T19:20:21.333533+01:00 twentytwo sddm-greeter-qt6[2705]: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/style.qml:399:13: QML QQuickImage: Error decoding: qrc:/qt-project.org/imports/QtQuick/VirtualKeyboard/Styles/Builtin/default/images/shift-fff.svg: Unsupported image format

It would be great to get the "nice" theme (breeze) back again.

#843693#42
Date:
2025-07-24 16:16:40 UTC
From:
To:
I'm experiencing the same issue after upgrading from Bookworm to Trixie! The Custom debian-breeze theme user config is not upgraded properly for Trixie's variant, and causes a white background! Even reinstalling sddm doesn't solve the problem. The only fix is that the user goes into the theme's config and manually tweaks the background path, which imho is critical bug as for now that Trixi is about to be released...

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