[SOLVED]Monitor Turning off and on after SDDM login

Ablon · 2025-11-18 00:36:45

Hello guys, having some problems with my old setup and a fresh install of Arch using SDDM/KDE.

Setup: Nvidia GTX960 connected via HDMI and DVI to a Monitor and TV, respectively.

Problem: The Monitor and TV lose signal for at least 5 seconds before showing my KDE Desktop.

lspci:

00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor DRAM Controller (rev 09)
00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor PCI Express Root Port (rev 09)
00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04)
00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 05)
00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 05)
00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 (rev b5)
00:1c.3 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 4 (rev b5)
00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 05)
00:1f.0 ISA bridge: Intel Corporation H61 Express Chipset LPC Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 6 Series/C200 Series Chipset Family 6 port Desktop SATA AHCI Controller (rev 05)
00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 05)
01:00.0 VGA compatible controller: NVIDIA Corporation GM206 [GeForce GTX 960] (rev a1)
01:00.1 Audio device: NVIDIA Corporation GM206 High Definition Audio Controller (rev a1)
02:00.0 Network controller: Qualcomm Atheros AR9287 Wireless Network Adapter (PCI-Express) (rev 01)
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet Controller (rev 02)

mkinitcipio.conf:

# vim:set ft=sh:
# MODULES
# The following modules are loaded before any boot hooks are
# run.  Advanced users may wish to specify all system modules
# in this array.  For instance:
#     MODULES=(usbhid xhci_hcd)
MODULES=(nvidia nvidia_modeset nvidia_uvm nvidia_drm)

# BINARIES
# This setting includes any additional binaries a given user may
# wish into the CPIO image.  This is run last, so it may be used to
# override the actual binaries included by a given hook
# BINARIES are dependency parsed, so you may safely ignore libraries
BINARIES=()

# FILES
# This setting is similar to BINARIES above, however, files are added
# as-is and are not parsed in any way.  This is useful for config files.
FILES=()

# HOOKS
# This is the most important setting in this file.  The HOOKS control the
# modules and scripts added to the image, and what happens at boot time.
# Order is important, and it is recommended that you do not change the
# order in which HOOKS are added.  Run 'mkinitcpio -H <hook name>' for
# help on a given hook.
# 'base' is _required_ unless you know precisely what you are doing.
# 'udev' is _required_ in order to automatically load modules
# 'filesystems' is _required_ unless you specify your fs modules in MODULES
# Examples:
##   This setup specifies all modules in the MODULES setting above.
##   No RAID, lvm2, or encrypted root is needed.
#    HOOKS=(base)
#
##   This setup will autodetect all modules for your system and should
##   work as a sane default
#    HOOKS=(base udev autodetect microcode modconf block filesystems fsck)
#
##   This setup will generate a 'full' image which supports most systems.
##   No autodetection is done.
#    HOOKS=(base udev microcode modconf block filesystems fsck)
#
##   This setup assembles a mdadm array with an encrypted root file system.
##   Note: See 'mkinitcpio -H mdadm_udev' for more information on RAID devices.
#    HOOKS=(base udev microcode modconf keyboard keymap consolefont block mdadm_udev encrypt filesystems fsck)
#
##   This setup loads an lvm2 volume group.
#    HOOKS=(base udev microcode modconf block lvm2 filesystems fsck)
#
##   This will create a systemd based initramfs which loads an encrypted root filesystem.
#    HOOKS=(base systemd autodetect microcode modconf kms keyboard sd-vconsole sd-encrypt block filesystems fsck)
#
##   NOTE: If you have /usr on a separate partition, you MUST include the
#    usr and fsck hooks.
HOOKS=(base systemd autodetect microcode modconf keyboard keymap sd-vconsole block filesystems fsck)

# COMPRESSION
# Use this to compress the initramfs image. By default, zstd compression
# is used for Linux ≥ 5.9 and gzip compression is used for Linux < 5.9.
# Use 'cat' to create an uncompressed image.
#COMPRESSION="zstd"
#COMPRESSION="gzip"
#COMPRESSION="bzip2"
#COMPRESSION="lzma"
#COMPRESSION="xz"
#COMPRESSION="lzop"
#COMPRESSION="lz4"

# COMPRESSION_OPTIONS
# Additional options for the compressor
#COMPRESSION_OPTIONS=()

# MODULES_DECOMPRESS
# Decompress loadable kernel modules and their firmware during initramfs
# creation. Switch (yes/no).
# Enable to allow further decreasing image size when using high compression
# (e.g. xz -9e or zstd --long --ultra -22) at the expense of increased RAM usage
# at early boot.
# Note that any compressed files will be placed in the uncompressed early CPIO
# to avoid double compression.
#MODULES_DECOMPRESS="no"

grub.cfg:

# GRUB boot loader configuration

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="Arch"
GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 quiet nvidia-drm.modeset=1 nvidia-drm.fbdev=1"
GRUB_CMDLINE_LINUX=""

# Preload both GPT and MBR modules so that they are not missed
GRUB_PRELOAD_MODULES="part_gpt part_msdos"

# Uncomment to enable booting from LUKS encrypted devices
#GRUB_ENABLE_CRYPTODISK=y

# Set to 'countdown' or 'hidden' to change timeout behavior,
# press ESC key to display menu.
GRUB_TIMEOUT_STYLE=menu

# Uncomment to use basic console
GRUB_TERMINAL_INPUT=console

# Uncomment to disable graphical terminal
#GRUB_TERMINAL_OUTPUT=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `videoinfo'
GRUB_GFXMODE=auto

# Uncomment to allow the kernel use the same resolution used by grub
GRUB_GFXPAYLOAD_LINUX=keep

# Uncomment if you want GRUB to pass to the Linux kernel the old parameter
# format "root=/dev/xxx" instead of "root=/dev/disk/by-uuid/xxx"
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
GRUB_DISABLE_RECOVERY=true

# Uncomment and set to the desired menu colors.  Used by normal and wallpaper
# modes only.  Entries specified as foreground/background.
#GRUB_COLOR_NORMAL="light-blue/black"
#GRUB_COLOR_HIGHLIGHT="light-cyan/blue"

# Uncomment one of them for the gfx desired, a image background or a gfxtheme
#GRUB_BACKGROUND="/path/to/wallpaper"
#GRUB_THEME="/path/to/gfxtheme"

# Uncomment to get a beep at GRUB start
#GRUB_INIT_TUNE="480 440 1"

# Uncomment to make GRUB remember the last selection. This requires
# setting 'GRUB_DEFAULT=saved' above.
#GRUB_SAVEDEFAULT=true

# Uncomment to disable submenus in boot menu
#GRUB_DISABLE_SUBMENU=y

# Probing for other operating systems is disabled for security reasons. Read
# documentation on GRUB_DISABLE_OS_PROBER, if still want to enable this
# functionality install os-prober and uncomment to detect and include other
# operating systems.
GRUB_DISABLE_OS_PROBER=false

Other logs:
journalctl -b
/var/log/Xorg.0.log

Last edited by Ablon (2025-11-18 21:46:58)

seth · 2025-11-18 21:28:56

SDDM is running on X11 but you're launching a KDE/wayland session.
https://archlinux.org/news/plasma-640-w … re-on-x11/

There're otherwise no glaring issues.
Does it still work w/ KDE/X11 or w/ a fresh user?

Generically, https://wiki.archlinux.org/title/KDE#Un … lution_set
Get rid of the setups in ~/.local/share/kscreen/

Hold on, it's just the monitor? Do you have another one?
Might just be nvidia being dog slow w/ the framebuffer switch.
You might want to test the KDE/X11 behavior of move SDDM to wayland as well: https://wiki.archlinux.org/title/SDDM#Wayland
But idk whether the latter will prevent any mode changes.

Last edited by seth (2025-11-18 21:30:56)

Ablon · 2025-11-18 21:46:15

You might want to test the KDE/X11 behavior of move SDDM to wayland as well: https://wiki.archlinux.org/title/SDDM#Wayland
But idk whether the latter will prevent any mode changes.

That was it, had to change from KDE to Wayland. ty Seth

Last edited by Ablon (2025-11-18 21:46:31)

Arch Linux

#1 2025-11-18 00:36:45

[SOLVED]Monitor Turning off and on after SDDM login

#2 2025-11-18 21:28:56

Re: [SOLVED]Monitor Turning off and on after SDDM login

#3 2025-11-18 21:46:15

Re: [SOLVED]Monitor Turning off and on after SDDM login

Board footer