[SOLVED] Black screen, no cursor on kde plasma, wayland, nvidia

Magnavode · 2025-08-05 09:11:12

Hello, I did a new install on a fresh PC. Previously I was dual booting ubuntu and windows 10. But I would really like a main linux workstation, but any help with the following issue would really be appreciated.

I'm getting a black screen (no cursor) whenever I start plasma. After a couple of seconds the monitor states that it has no input and I have to switch to tty2 in order to continue.
My monitor is a SAMSUNG odyssey CRG9, a super ultrawide, so there might be something funky going on with the resolution. However I don't think it's cable related as ubuntu was handling it fine and the shell is also supporting 5120x1440.

I've reinstalled so everything is reset, but in my testing I found that plugging in my tv into the gpu will start plasma just fine (however sddm boots to black screen). (update: the new install also works just fine on the tv)

My installation procedure: (I have the wiki open on a laptop and note down whatever command I enter)

# PARTITIONS
# /boot    1GiB
# [SWAP]  30G
# /              about 900G
cfdisk /dev/nvme0n1
mkfs.ext4 /dev/nvme0n1p3
mkswap /dev/nvme0n1p2
mkfs.fat -F 32 /dev/nvme0n1p1

mount /dev/nvme0n1p3 /mnt
mount --mkdir /dev/nvme0n1p1 /mnt/boot/efi
swapon /dev/nvme0n1p2

pacstrap /mnt base linux linux-firmware amd-ucode base-devel grub efibootmgr nano networkmanager less nvidia-open plasma sddm konsole kate
genfstab -U /mnt >> /mnt/etc/fstab
arch-chroot /mnt

ln -sf /usr/share/zoneinfo/redacted/redacted /etc/localtime
hwclock --systohc
nano /etc/locale.gen # uncomment "en_US.UTF-8 UTF-8"
locale-gen
echo "LANG=en_US.UTF-8" > /etc/locale.conf
echo "KEYMAP=us" > /etc/vconsole.conf

echo "linux-desktop" > /etc/hostname

cat << EOT >> /etc/environment
GMB_BACKEND=nvidia-drm
__GLX_VENDOR_LIBRARY_NAME=nvidia
QT_QPA_PLATFORM=wayland
EOT

useradd -m -G wheel -s /usr/bin/bash magnavode
passwd magnavode
EDITOR=nano visudo # uncomment "%wheel ALL=(ALL) ALL"
su magnavode
echo "export EDITOR=nano" >> ~/.bashrc

sudo systemctl enable NetworkManager

sudo grub-install /dev/nvme0n1
sudo nano /etc/default/grub # append "nvidia_drm.modeset=1 nvidia_drm.fbdev=1" to GRUB_CMDLINE_LINUX_DEFAUT
sudo grub-mkconfig -0 /boot/grub/grub.cfg

sudo reboot now

# sddm is installed but not enabled in systemd so I can test things

/usr/lib/plasma-dbus-run-session-if-needed /usr/bin/startplasma-wayland

journalctl -b:
https://0x0.st/8hTu.log

Last edited by Magnavode (2025-08-10 10:46:16)

seth · 2025-08-05 15:23:54

Aug 05 09:01:21 linux-desktop kwin_wayland[826]: kwin_xwl: Could not find a matching X RandR CRTC/output to set as primary for KWin::PlaceholderOutput(0x55ea04026500, name="Placeholder-1", geometry=QRect(0,0 1920x1080), scale=1)
Aug 05 09:01:21 linux-desktop kwin_wayland[826]: kwin_xwl: Could not find a matching X RandR CRTC/output to set as primary for KWin::PlaceholderOutput(0x55ea04026500, name="Placeholder-1", geometry=QRect(0,0 1920x1080), scale=1)
Aug 05 09:01:23 linux-desktop kwin_wayland[826]: kwin_xwl: Could not find a matching X RandR CRTC/output to set as primary for KWin::DrmOutput(0x55ea02cf2fa0, name="HDMI-A-2", geometry=QRect(0,0 5120x1440), scale=1)

Aug 05 08:59:58 linux-desktop kernel: The simpledrm driver will not be probed
Aug 05 08:59:58 linux-desktop kernel: Kernel command line: BOOT_IMAGE=/boot/vmlinuz-linux root=UUID=bbc3bde5-1b03-4c38-8cc4-c524e87cadc0 rw loglevel=3 quiet nvidia_drm.modeset=1 nvidia_drm.fbdev=1
…
Aug 05 08:59:58 linux-desktop kernel: amdgpu 0000:13:00.0: [drm] Cannot find any crtc or sizes
Aug 05 09:00:01 linux-desktop kernel: fbcon: nvidia-drmdrmfb (fb0) is primary device
Aug 05 09:00:01 linux-desktop kernel: nvidia 0000:01:00.0: [drm] fb0: nvidia-drmdrmfb frame buffer device

If you cannot disable the AMD gpu try https://wiki.archlinux.org/title/KDE#Me … -specific) and also see https://wiki.archlinux.org/title/KDE#Un … lution_set

Edit: alternatively attach the output to the AMD GPU for a regular prime setup.

Last edited by seth (2025-08-05 15:24:43)

Magnavode · 2025-08-10 10:44:10

Thank you for looking in to the issue.

Setting KWIN_DRM_DEVICES has fixed the placeholder output (the logging is gone). However it did not fix the black screen.

echo "KWIN_DRM_DEVICES=/dev/dri/card1" >> etc/environment

I've now resolved the issue by switching to a displayport cable. Even had to modify my case in order to make it fit (there was a lip in the way).

Last edited by Magnavode (2025-08-10 10:45:17)

Arch Linux

#1 2025-08-05 09:11:12

[SOLVED] Black screen, no cursor on kde plasma, wayland, nvidia

#2 2025-08-05 15:23:54

Re: [SOLVED] Black screen, no cursor on kde plasma, wayland, nvidia

#3 2025-08-10 10:44:10

Re: [SOLVED] Black screen, no cursor on kde plasma, wayland, nvidia

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