Plymouth -> LightDM handoff hang on HP Victus AMD/NVIDIA hybrid system

Graphics / Linux Linux
1

Suggested Bug Title

Plymouth splash leaves boot stuck at HP/Victus spinner during handoff to LightDM on AMD/NVIDIA hybrid laptop; plymouth.enable=0 fixes graphical boot

Suggested Package

Primary package: plymouth

Possibly affected or useful for triage:

  • lightdm
  • nvidia-prime
  • nvidia-driver-535
  • linux-image-generic-hwe-24.04
  • AMDGPU DRM/KMS stack

Summary

On an HP Victus 15 laptop with AMD Phoenix3 integrated graphics and an NVIDIA RTX 4050 Mobile dGPU, normal graphical boot became stuck at the vendor splash/spinner stage when Plymouth was enabled through the default quiet splash GRUB command line.

The system was not actually failing to boot, and the GPUs were not dead. Multiple tests showed that the kernel, NVIDIA 535 driver, NVIDIA DRM, AMDGPU, LightDM, and the Cinnamon session could all work when Plymouth was removed from the early graphical boot path.

The decisive workaround was:

GRUB_CMDLINE_LINUX_DEFAULT="quiet plymouth.enable=0"

After making that permanent and running update-grub, the machine booted normally into the desktop without nomodeset, without recovery mode, and without manually starting the display manager.

Environment

Current working system state:

OS: Ubuntu 24.04.3 LTS (noble)
Current kernel: 6.17.0-20-generic
Incident kernel: 6.17.0-19-generic
Host: ilyyeees-Victus-by-HP-Gaming-Laptop-15
Model: HP Victus by HP Gaming Laptop 15-fb2xxx
BIOS: F.08, 2025-10-29
Secure Boot: enabled
Display manager: LightDM
Desktop session: Cinnamon
PRIME mode: on-demand
Current GRUB cmdline: quiet plymouth.enable=0

Relevant package versions currently installed:

plymouth                 24.004.60-1ubuntu7.1
lightdm                  1.30.0-0ubuntu14
gdm3                     46.2-1ubuntu1~24.04.6
nvidia-driver-535        535.288.01-0ubuntu0.24.04.2
nvidia-prime             0.8.17.2
linux-image-6.17.0-20    6.17.0-20.20~24.04.1

GPU hardware:

01:00.0 VGA compatible controller [0300]: NVIDIA Corporation AD107M [GeForce RTX 4050 Max-Q / Mobile] [10de:28a1] (rev a1)
    Subsystem: Hewlett-Packard Company AD107M [GeForce RTX 4050 Max-Q / Mobile] [103c:8c2f]
    Kernel driver in use: nvidia
    Kernel modules: nvidiafb, nouveau, nvidia_drm, nvidia

06:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Phoenix3 [1002:1900] (rev c6)
    Subsystem: Hewlett-Packard Company Phoenix3 [103c:8c2f]
    Kernel driver in use: amdgpu
    Kernel modules: amdgpu

Current NVIDIA state:

prime-select query: on-demand
nvidia-smi: NVIDIA GeForce RTX 4050 Laptop GPU, 535.288.01

User-Visible Failure

With Plymouth enabled through the normal quiet splash boot path, the laptop showed the HP/Victus boot screen and spinner, then never visibly transitioned to a usable login screen.

The system appeared stuck from the user’s perspective, but later diagnostics showed that the machine could boot normally when Plymouth was removed from the path. This points to an early graphics/VT handoff issue rather than a hard kernel boot failure.

Expected Behavior

With quiet splash enabled, Plymouth should hand off cleanly to LightDM, the login screen should appear, and the desktop session should start normally.

Actual Behavior

With quiet splash enabled, the visible display stayed stuck on the boot splash/spinner path during the transition to the graphical login. The same graphics stack worked when Plymouth was disabled.

Key Evidence

This combination of test results is the core of the report:

  1. A normal graphical boot with quiet splash failed visually.
  2. A normal boot without nomodeset, but with systemd.unit=multi-user.target plymouth.enable=0, reached a text console.
  3. From that text console, starting lightdm.service manually made the graphical environment appear.
  4. A normal graphical boot with only plymouth.enable=0 worked.
  5. Making plymouth.enable=0 permanent in /etc/default/grub fixed normal boot long-term.

That strongly suggests the failing component is the early boot splash/display handoff path, not the GPU hardware, not Secure Boot, not the NVIDIA 535 module load, and not LightDM by itself.

Why This Does Not Look Like Hardware Failure

The machine repeatedly showed successful GPU initialization outside the failing Plymouth handoff path:

NVRM: loading NVIDIA UNIX x86_64 Kernel Module 535.288.01
nvidia-modeset: Loading NVIDIA Kernel Mode Setting Driver
[drm] Initialized nvidia-drm
[drm] amdgpu kernel modesetting enabled
amdgpu ... initializing kernel modesetting
[drm] Initialized amdgpu 3.64.0
fbcon: amdgpudrmfb (fb0) is primary device

A later live check also confirms the NVIDIA card is present and usable:

NVIDIA GeForce RTX 4050 Laptop GPU, 535.288.01

Relevant History

Before the final diagnosis, the system went through NVIDIA driver churn:

2026-03-24 17:45:23: installed nvidia-driver-580 and nvidia-prime
2026-03-24 18:36:31: purged ^nvidia-*
2026-03-24 18:45:23: installed nvidia-driver-535 and nvidia-prime
2026-03-25 01:20:29: purged nvidia-*
2026-03-25 01:20:53: ran apt autoremove

After that, the system was temporarily in a degraded recovery state:

  • booting with nomodeset
  • proprietary NVIDIA driver removed
  • nouveau active instead of nvidia
  • stale NVIDIA/PRIME modprobe files remained
  • an AMD Xorg override existed

Those issues were cleaned up during the investigation. However, even after the NVIDIA 535 stack and PRIME on-demand mode were restored, the visible graphical boot still failed until Plymouth was disabled.

Steps That Were Tried

The following changes did not fully solve the visible boot failure by themselves:

  • Reinstalling nvidia-driver-535
  • Installing matching prebuilt NVIDIA kernel modules for the active HWE kernel
  • Rebuilding initramfs and GRUB
  • Switching from LightDM to GDM3
  • Re-enabling GDM Wayland
  • Testing AMD PSR disabled via amdgpu.dcdebugmask=0x10
  • Installing nvidia-prime
  • Setting prime-select on-demand
  • Returning to LightDM with AMD driving the visible display path
  • Disabling the LightDM nvidia-prime /sbin/prime-offload hook

The change that did solve it:

Remove active splash usage and add plymouth.enable=0

Current Workaround

The machine is currently stable with:

GRUB_CMDLINE_LINUX_DEFAULT="quiet plymouth.enable=0"

This was applied by backing up /etc/default/grub, replacing/removing splash, adding plymouth.enable=0, then running:

sudo update-grub
sudo reboot

Suggested Triage Direction

Please treat this as a Plymouth/display-manager handoff problem on a hybrid graphics system.

The strongest hypothesis is:

  1. AMDGPU and NVIDIA DRM/KMS both initialize successfully.
  2. Plymouth owns the visible boot display early because splash is present.
  3. LightDM later starts and tries to take over the graphical VT/display path.
  4. The transition from Plymouth to LightDM does not complete cleanly.
  5. The machine keeps booting in the background, but the user-visible display remains stuck on the splash/spinner path.

This is supported by the fact that the same system works when:

  • Plymouth is disabled, and
  • LightDM is started manually after a text-mode boot.

Requested Outcome

Ideally Plymouth should either:

  • hand off cleanly to LightDM on this hybrid AMD/NVIDIA setup, or
  • fail gracefully and release the display/VT so LightDM can present the greeter.

At minimum, this hardware/driver combination may need a quirk, better logging around the handoff, or guidance for disabling Plymouth on affected hybrid graphics systems.

Appendix A: Current Working State Command Outputs

Collected on 2026-04-24 after the workaround was made permanent.

$ lsb_release -a
Distributor ID: Ubuntu
Description:    Ubuntu 24.04.3 LTS
Release:        24.04
Codename:       noble

$ uname -a
Linux ilyyeees-Victus-by-HP-Gaming-Laptop-15 6.17.0-20-generic #20~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Mar 19 01:28:37 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

$ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-6.17.0-20-generic root=UUID=6453a692-5271-44c5-9a07-c1566813357b ro quiet plymouth.enable=0

$ dpkg-query -W -f='${Package}\t${Version}\n' plymouth lightdm gdm3 nvidia-driver-535 nvidia-prime linux-image-$(uname -r)
gdm3                            46.2-1ubuntu1~24.04.6
lightdm                         1.30.0-0ubuntu14
linux-image-6.17.0-20-generic   6.17.0-20.20~24.04.1
nvidia-driver-535               535.288.01-0ubuntu0.24.04.2
nvidia-prime                    0.8.17.2
plymouth                        24.004.60-1ubuntu7.1

$ mokutil --sb-state
SecureBoot enabled

$ prime-select query
on-demand

$ nvidia-smi --query-gpu=name,driver_version --format=csv,noheader
NVIDIA GeForce RTX 4050 Laptop GPU, 535.288.01

$ systemctl is-active display-manager lightdm gdm
active
active
inactive

$ readlink -f /etc/systemd/system/display-manager.service
/usr/lib/systemd/system/lightdm.service

$ cat /etc/X11/default-display-manager
/usr/sbin/lightdm

$ grep -n '^GRUB_CMDLINE_LINUX_DEFAULT=' /etc/default/grub
10:GRUB_CMDLINE_LINUX_DEFAULT="quiet plymouth.enable=0"

$ cat /etc/prime-discrete
on-demand

Appendix B: Final Permanent Fix Log

== Permanent Plymouth disable started at 2026-03-25T03:42:11+01:00 ==
Backup dir: /home/ilyyeees/Desktop/inverstigate/plymouth-disable-backup-20260325-034211
Log file:   /home/ilyyeees/Desktop/inverstigate/plymouth-disable-run-20260325-034211.log
Backed up /etc/default/grub

== Updated GRUB default cmdline ==
10:GRUB_CMDLINE_LINUX_DEFAULT="quiet plymouth.enable=0"

== Rebuilding GRUB ==
Sourcing file `/etc/default/grub'
Generating grub configuration file ...
Found theme: /boot/grub/themes/1920x1080/theme.txt
Found linux image: /boot/vmlinuz-6.17.0-19-generic
Found initrd image: /boot/initrd.img-6.17.0-19-generic
Found linux image: /boot/vmlinuz-6.17.0-14-generic
Found initrd image: /boot/initrd.img-6.17.0-14-generic
Found memtest86+ 64bit EFI image: /boot/memtest86+x64.efi
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Found Windows Boot Manager on /dev/nvme0n1p1@/EFI/Microsoft/Boot/bootmgfw.efi
Adding boot menu entry for UEFI Firmware Settings ...
done

Permanent Plymouth disable completed.

Next step:
1. Reboot normally.
2. Do not add "nomodeset".

Appendix C: Permanent Fix Script

#!/usr/bin/env bash

set -euo pipefail

if [[ ${EUID:-$(id -u)} -ne 0 ]]; then
  echo "Run this script with sudo."
  exit 1
fi

REPORT_DIR="/home/ilyyeees/Desktop/inverstigate"
STAMP="$(date +%Y%m%d-%H%M%S)"
BACKUP_DIR="$REPORT_DIR/plymouth-disable-backup-$STAMP"
LOG_FILE="$REPORT_DIR/plymouth-disable-run-$STAMP.log"

mkdir -p "$BACKUP_DIR"
touch "$LOG_FILE"
exec > >(tee -a "$LOG_FILE") 2>&1

echo "== Permanent Plymouth disable started at $(date -Is) =="
echo "Backup dir: $BACKUP_DIR"
echo "Log file:   $LOG_FILE"

cp -a /etc/default/grub "$BACKUP_DIR/grub"
echo "Backed up /etc/default/grub"

python3 - <<'PY'
from pathlib import Path

path = Path("/etc/default/grub")
text = path.read_text()
old = 'GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"'
if old in text:
    text = text.replace(old, 'GRUB_CMDLINE_LINUX_DEFAULT="quiet plymouth.enable=0"', 1)
else:
    import re
    pattern = re.compile(r'^GRUB_CMDLINE_LINUX_DEFAULT="([^"]*)"$', re.M)
    match = pattern.search(text)
    if not match:
        raise SystemExit("Could not find GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub")
    parts = [p for p in match.group(1).split() if p not in {"splash", "nomodeset", "plymouth.enable=0"}]
    parts.append("plymouth.enable=0")
    new = 'GRUB_CMDLINE_LINUX_DEFAULT="' + " ".join(parts) + '"'
    text = pattern.sub(new, text, count=1)
path.write_text(text)
PY

echo
echo "== Updated GRUB default cmdline =="
grep -n '^GRUB_CMDLINE_LINUX_DEFAULT=' /etc/default/grub

echo
echo "== Rebuilding GRUB =="
update-grub

cat <<EOF

Permanent Plymouth disable completed.

Next step:
1. Reboot normally.
2. Do not add "nomodeset".

EOF

Appendix D: Text-Mode Diagnostic Probe Log

== LightDM TTY probe started at 2026-03-25T03:28:31+01:00 ==
Run log:            /home/ilyyeees/Desktop/inverstigate/tty-lightdm-probe-run-20260325-032831.log
LightDM journal:    /home/ilyyeees/Desktop/inverstigate/tty-lightdm-journal-20260325-032831.txt
Graphical journal:  /home/ilyyeees/Desktop/inverstigate/tty-lightdm-graphical-20260325-032831.txt
LightDM log copy:   /home/ilyyeees/Desktop/inverstigate/tty-lightdm-lightdm-log-20260325-032831.log
LightDM X log copy: /home/ilyyeees/Desktop/inverstigate/tty-lightdm-x-0-log-20260325-032831.log
Greeter log copy:   /home/ilyyeees/Desktop/inverstigate/tty-lightdm-seat0-greeter-20260325-032831.log
State snapshot:     /home/ilyyeees/Desktop/inverstigate/tty-lightdm-state-20260325-032831.txt

== Baseline ==
Kernel cmdline: BOOT_IMAGE=/boot/vmlinuz-6.17.0-19-generic root=UUID=6453a692-5271-44c5-9a07-c1566813357b ro systemd.unit=multi-user.target plymouth.enable=0

total 0
drwxr-xr-x  2 root root        120 Mar 25 03:27 by-path
crw-rw----+ 1 root video  226,   1 Mar 25 03:27 card1
crw-rw----+ 1 root video  226,   2 Mar 25 03:27 card2
crw-rw----+ 1 root render 226, 128 Mar 25 03:27 renderD128
crw-rw----+ 1 root render 226, 129 Mar 25 03:27 renderD129

prime-select query: on-demand
/etc/X11/default-display-manager: /usr/sbin/lightdm
display-manager.service -> /usr/lib/systemd/system/lightdm.service

== Starting LightDM for a controlled probe ==

== Capturing logs while LightDM is active ==

== Stopping LightDM again ==

== Probe completed ==
-rw-r--r-- 1 root root 40601 Mar 25 03:28 /home/ilyyeees/Desktop/inverstigate/tty-lightdm-graphical-20260325-032831.txt
-rw-r--r-- 1 root root  1168 Mar 25 03:28 /home/ilyyeees/Desktop/inverstigate/tty-lightdm-journal-20260325-032831.txt
-rw------- 1 root root 70442 Mar 25 03:28 /home/ilyyeees/Desktop/inverstigate/tty-lightdm-lightdm-log-20260325-032831.log
-rw-r--r-- 1 root root  1506 Mar 25 03:28 /home/ilyyeees/Desktop/inverstigate/tty-lightdm-probe-run-20260325-032831.log
-rw------- 1 root root 50718 Mar 25 03:28 /home/ilyyeees/Desktop/inverstigate/tty-lightdm-seat0-greeter-20260325-032831.log
-rw-r--r-- 1 root root  1882 Mar 25 03:28 /home/ilyyeees/Desktop/inverstigate/tty-lightdm-state-20260325-032831.txt
-rw------- 1 root root 28465 Mar 25 03:28 /home/ilyyeees/Desktop/inverstigate/tty-lightdm-x-0-log-20260325-032831.log

Next step:
1. Stay in the TTY if possible.
2. Reboot back into your normal recovery path if needed.
3. Send the new tty-lightdm-* files from /home/ilyyeees/Desktop/inverstigate.

Note: The copied tty-lightdm-* files in the current investigation folder are now zero-length, likely because of permissions/copying after collection. The run log above still records that the live capture created non-empty files at the time of the test.

Appendix E: Normal Non-Plymouth GPU Initialization Evidence

[Wed Mar 25 03:14:15 2026] fbcon: Taking over console
[Wed Mar 25 03:14:16 2026] ACPI: bus type drm_connector registered
[Wed Mar 25 03:14:16 2026] simple-framebuffer simple-framebuffer.0: [drm] Registered 1 planes with drm panic
[Wed Mar 25 03:14:16 2026] [drm] Initialized simpledrm 1.0.0 for simple-framebuffer.0 on minor 0
[Wed Mar 25 03:14:16 2026] simple-framebuffer simple-framebuffer.0: [drm] fb0: simpledrmdrmfb frame buffer device
[Wed Mar 25 03:14:17 2026] systemd[1]: Starting modprobe@drm.service - Load Kernel Module drm...
[Wed Mar 25 03:14:17 2026] systemd[1]: modprobe@drm.service: Deactivated successfully.
[Wed Mar 25 03:14:17 2026] systemd[1]: Finished modprobe@drm.service - Load Kernel Module drm.
[Wed Mar 25 03:14:17 2026] [drm] Initialized amdxdna_accel_driver 0.0.0 for 0000:07:00.1 on minor 0
[Wed Mar 25 03:14:18 2026] nvidia: loading out-of-tree module taints kernel.
[Wed Mar 25 03:14:18 2026] nvidia: module license 'NVIDIA' taints kernel.
[Wed Mar 25 03:14:18 2026] nvidia: module license taints kernel.
[Wed Mar 25 03:14:18 2026] nvidia-nvlink: Nvlink Core is being initialized, major device number 509
[Wed Mar 25 03:14:18 2026] nvidia 0000:01:00.0: enabling device (0002 -> 0003)
[Wed Mar 25 03:14:18 2026] nvidia 0000:01:00.0: vgaarb: VGA decodes changed: olddecodes=io+mem,decodes=none:owns=none
[Wed Mar 25 03:14:18 2026] NVRM: loading NVIDIA UNIX x86_64 Kernel Module  535.288.01  Tue Nov 18 18:26:41 UTC 2025
[Wed Mar 25 03:14:18 2026] nvidia-modeset: Loading NVIDIA Kernel Mode Setting Driver for UNIX platforms  535.288.01  Tue Nov 18 18:19:41 UTC 2025
[Wed Mar 25 03:14:18 2026] [drm] [nvidia-drm] [GPU ID 0x00000100] Loading driver
[Wed Mar 25 03:14:18 2026] input: HDA NVidia HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:01.1/0000:01:00.1/sound/card0/input21
[Wed Mar 25 03:14:18 2026] input: HDA NVidia HDMI/DP,pcm=7 as /devices/pci0000:00/0000:00:01.1/0000:01:00.1/sound/card0/input22
[Wed Mar 25 03:14:18 2026] input: HDA NVidia HDMI/DP,pcm=8 as /devices/pci0000:00/0000:00:01.1/0000:01:00.1/sound/card0/input23
[Wed Mar 25 03:14:18 2026] input: HDA NVidia HDMI/DP,pcm=9 as /devices/pci0000:00/0000:00:01.1/0000:01:00.1/sound/card0/input24
[Wed Mar 25 03:14:19 2026] [drm] Initialized nvidia-drm 0.0.0 for 0000:01:00.0 on minor 1
[Wed Mar 25 03:14:19 2026] [drm] amdgpu kernel modesetting enabled.
[Wed Mar 25 03:14:19 2026] amdgpu: vga_switcheroo: detected switching method \_SB_.PCI0.GP17.VGA_.ATPX handle
[Wed Mar 25 03:14:19 2026] amdgpu: ATPX version 1, functions 0x00000001
[Wed Mar 25 03:14:19 2026] amdgpu: ATPX Hybrid Graphics
[Wed Mar 25 03:14:19 2026] amdgpu: Virtual CRAT table created for CPU
[Wed Mar 25 03:14:19 2026] amdgpu: Topology: Add CPU node
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: enabling device (0006 -> 0007)
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: initializing kernel modesetting (IP DISCOVERY 0x1002:0x1900 0x103C:0x8C2F 0xC6).
[Wed Mar 25 03:14:19 2026] nvidia_uvm: module uses symbols nvUvmInterfaceDisableAccessCntr from proprietary module nvidia, inheriting taint.
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: register mmio base: 0xFC700000
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: register mmio size: 524288
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 0 <soc21_common>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 1 <gmc_v11_0>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 2 <ih_v6_0>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 3 <psp>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 4 <smu>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 5 <dm>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 6 <gfx_v11_0>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 7 <sdma_v6_0>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 8 <vcn_v4_0>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 9 <jpeg_v4_0>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: detected ip block number 10 <mes_v11_0>
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: Fetched VBIOS from VFCT
[Wed Mar 25 03:14:19 2026] amdgpu: ATOM BIOS: 113-PHXGENERIC-001
[Wed Mar 25 03:14:19 2026] nvidia-uvm: Loaded the UVM driver, major device number 506.
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: vgaarb: deactivate vga console
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: Trusted Memory Zone (TMZ) feature enabled
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: vm size is 262144 GB, 4 levels, block size is 9-bit, fragment size is 9-bit
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: VRAM: 512M 0x0000008000000000 - 0x000000801FFFFFFF (512M used)
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: GART: 512M 0x00007FFF00000000 - 0x00007FFF1FFFFFFF
[Wed Mar 25 03:14:19 2026] [drm] Detected VRAM RAM=512M, BAR=512M
[Wed Mar 25 03:14:19 2026] [drm] RAM width 128bits DDR5
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: amdgpu: 512M of VRAM memory ready
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: amdgpu: 11663M of GTT memory ready.
[Wed Mar 25 03:14:19 2026] [drm] GART: num cpu pages 131072, num gpu pages 131072
[Wed Mar 25 03:14:19 2026] [drm] PCIE GART of 512M enabled (table at 0x000000801FD00000).
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: [drm] Loading DMUB firmware via PSP: version=0x08005300
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: Found VCN firmware Version ENC: 1.19 DEC: 7 VEP: 0 Revision: 0
[Wed Mar 25 03:14:19 2026] amdgpu 0000:06:00.0: amdgpu: reserve 0x4000000 from 0x8018000000 for PSP TMR
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: RAS: optional ras ta ucode is not available
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: RAP: optional rap ta ucode is not available
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: SECUREDISPLAY: optional securedisplay ta ucode is not available
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: SMU is initialized successfully!
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] Display Core v3.2.340 initialized on DCN 3.1.4
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] DP-HDMI FRL PCON supported
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] DMUB hardware initialized: version=0x08005300
[Wed Mar 25 03:14:20 2026] snd_hda_intel 0000:06:00.1: bound 0000:06:00.0 (ops amdgpu_dm_audio_component_bind_ops [amdgpu])
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] PSR support 1, DC PSR ver 0, sink PSR ver 1 DPCD caps 0xa su_y_granularity 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] PSR support 0, DC PSR ver -1, sink PSR ver 0 DPCD caps 0x0 su_y_granularity 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] PSR support 0, DC PSR ver -1, sink PSR ver 0 DPCD caps 0x0 su_y_granularity 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] PSR support 0, DC PSR ver -1, sink PSR ver 0 DPCD caps 0x0 su_y_granularity 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] PSR support 0, DC PSR ver -1, sink PSR ver 0 DPCD caps 0x0 su_y_granularity 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] PSR support 0, DC PSR ver -1, sink PSR ver 0 DPCD caps 0x0 su_y_granularity 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] PSR support 0, DC PSR ver -1, sink PSR ver 0 DPCD caps 0x0 su_y_granularity 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] PSR support 0, DC PSR ver -1, sink PSR ver 0 DPCD caps 0x0 su_y_granularity 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] PSR support 0, DC PSR ver -1, sink PSR ver 0 DPCD caps 0x0 su_y_granularity 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: MES FW version must be >= 0x7f to enable LR compute workaround.
[Wed Mar 25 03:14:20 2026] kfd kfd: amdgpu: Allocated 3969056 bytes on gart
[Wed Mar 25 03:14:20 2026] kfd kfd: amdgpu: Total number of KFD nodes to be created: 1
[Wed Mar 25 03:14:20 2026] amdgpu: Virtual CRAT table created for GPU
[Wed Mar 25 03:14:20 2026] amdgpu: Topology: Add dGPU node [0x1900:0x1002]
[Wed Mar 25 03:14:20 2026] kfd kfd: amdgpu: added device 1002:1900
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: SE 1, SH per SE 2, CU per SH 6, active_cu_number 8
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring gfx_0.0.0 uses VM inv eng 0 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring comp_1.0.0 uses VM inv eng 1 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring comp_1.1.0 uses VM inv eng 4 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring comp_1.2.0 uses VM inv eng 6 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring comp_1.3.0 uses VM inv eng 7 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring comp_1.0.1 uses VM inv eng 8 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring comp_1.1.1 uses VM inv eng 9 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring comp_1.2.1 uses VM inv eng 10 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring comp_1.3.1 uses VM inv eng 11 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring sdma0 uses VM inv eng 12 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring vcn_unified_0 uses VM inv eng 0 on hub 8
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring jpeg_dec uses VM inv eng 1 on hub 8
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: ring mes_kiq_3.1.0 uses VM inv eng 13 on hub 0
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: Runtime PM not available
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: amdgpu: [drm] Using custom brightness curve
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: [drm] Registered 4 planes with drm panic
[Wed Mar 25 03:14:20 2026] [drm] Initialized amdgpu 3.64.0 for 0000:06:00.0 on minor 2
[Wed Mar 25 03:14:20 2026] fbcon: amdgpudrmfb (fb0) is primary device
[Wed Mar 25 03:14:20 2026] [drm] pre_validate_dsc:1635 MST_DSC dsc precompute is not needed
[Wed Mar 25 03:14:20 2026] amdgpu 0000:06:00.0: [drm] fb0: amdgpudrmfb frame buffer device

Appendix F: NVIDIA 535 Repair Log Excerpt

== GPU repair started at 2026-03-25T01:46:09+01:00 ==
Backup dir: /home/ilyyeees/Desktop/inverstigate/gpu-fix-backup-20260325-014609
Log file:   /home/ilyyeees/Desktop/inverstigate/gpu-fix-run-20260325-014609.log
Backed up /etc/default/grub -> /home/ilyyeees/Desktop/inverstigate/gpu-fix-backup-20260325-014609/etc/default/grub
Backed up /etc/X11/default-display-manager -> /home/ilyyeees/Desktop/inverstigate/gpu-fix-backup-20260325-014609/etc/X11/default-display-manager
Backed up /usr/lib/modprobe.d/blacklist-nvidia.conf -> /home/ilyyeees/Desktop/inverstigate/gpu-fix-backup-20260325-014609/usr/lib/modprobe.d/blacklist-nvidia.conf
Disabled /usr/lib/modprobe.d/blacklist-nvidia.conf
Backed up /usr/lib/modprobe.d/nvidia-kms.conf -> /home/ilyyeees/Desktop/inverstigate/gpu-fix-backup-20260325-014609/usr/lib/modprobe.d/nvidia-kms.conf
Disabled /usr/lib/modprobe.d/nvidia-kms.conf
Backed up /usr/lib/modprobe.d/nvidia-runtimepm.conf -> /home/ilyyeees/Desktop/inverstigate/gpu-fix-backup-20260325-014609/usr/lib/modprobe.d/nvidia-runtimepm.conf
Disabled /usr/lib/modprobe.d/nvidia-runtimepm.conf
Backed up /etc/u-d-c-nvidia-runtimepm-override -> /home/ilyyeees/Desktop/inverstigate/gpu-fix-backup-20260325-014609/etc/u-d-c-nvidia-runtimepm-override
Disabled /etc/u-d-c-nvidia-runtimepm-override
Backed up /etc/X11/xorg.conf.d/20-amdgpu.conf -> /home/ilyyeees/Desktop/inverstigate/gpu-fix-backup-20260325-014609/etc/X11/xorg.conf.d/20-amdgpu.conf
Disabled /etc/X11/xorg.conf.d/20-amdgpu.conf

== Cleaning the root cron browser launch if it exists ==
No matching root crontab entries found

== Installing NVIDIA 535 for kernel 6.17 ==
...
nvidia-drm.ko: OK
nvidia-modeset.ko: OK
nvidia-peermem.ko: OK
nvidia-uvm.ko: OK
nvidia.ko: OK
...
== Rebuilding boot artifacts ==
update-initramfs: Generating /boot/initrd.img-6.17.0-19-generic
update-initramfs: Generating /boot/initrd.img-6.17.0-14-generic
Sourcing file `/etc/default/grub'
Generating grub configuration file ...
...
== Final state ==
Current kernel: 6.17.0-19-generic
Current cmdline: BOOT_IMAGE=/boot/vmlinuz-6.17.0-19-generic root=UUID=6453a692-5271-44c5-9a07-c1566813357b ro nomodeset

This shows that the NVIDIA 535 package/module side was repaired before the final Plymouth diagnosis.

Appendix G: NVIDIA PRIME Restoration Log

== NVIDIA PRIME repair started at 2026-03-25T02:35:38+01:00 ==
Backup dir: /home/ilyyeees/Desktop/inverstigate/nvidia-prime-fix-backup-20260325-023538
Log file:   /home/ilyyeees/Desktop/inverstigate/nvidia-prime-fix-run-20260325-023538.log
Backed up /etc/prime-discrete -> /home/ilyyeees/Desktop/inverstigate/nvidia-prime-fix-backup-20260325-023538/etc/prime-discrete
Missing before install: /lib/modprobe.d/blacklist-nvidia.conf
Missing before install: /lib/modprobe.d/nvidia-kms.conf
Missing before install: /lib/modprobe.d/nvidia-runtimepm.conf
Backed up /etc/default/grub -> /home/ilyyeees/Desktop/inverstigate/nvidia-prime-fix-backup-20260325-023538/etc/default/grub
...
The following NEW packages will be installed:
  nvidia-prime
...
Setting up nvidia-prime (0.8.17.2) ...

== Enabling PRIME on-demand mode ==
Info: selecting the on-demand profile
Writing /lib/modprobe.d/nvidia-runtimepm.conf
Updating the initramfs. Please wait for the operation to complete:
Done

== Final PRIME state ==
prime-select query: on-demand
/etc/prime-discrete: on-demand

/lib/modprobe.d/blacklist-nvidia.conf

/lib/modprobe.d/nvidia-kms.conf
# This file was generated by nvidia-prime
# Set value to 1 to enable modesetting
options nvidia-drm modeset=1
/lib/modprobe.d/nvidia-runtimepm.conf
options nvidia "NVreg_DynamicPowerManagement=0x02"

NVIDIA PRIME repair completed.

Appendix H: Final LightDM/AMDGPU/PRIME Configuration Test

== LightDM + AMDGPU hybrid fallback started at 2026-03-25T03:00:00+01:00 ==
Backup dir: /home/ilyyeees/Desktop/inverstigate/lightdm-amdgpu-prime-backup-20260325-030000
Log file:   /home/ilyyeees/Desktop/inverstigate/lightdm-amdgpu-prime-run-20260325-030000.log
Backed up /etc/X11/default-display-manager -> /home/ilyyeees/Desktop/inverstigate/lightdm-amdgpu-prime-backup-20260325-030000/etc/X11/default-display-manager
Backed up /etc/systemd/system/display-manager.service -> /home/ilyyeees/Desktop/inverstigate/lightdm-amdgpu-prime-backup-20260325-030000/etc/systemd/system/display-manager.service
Backed up /etc/X11/xorg.conf.d/20-amdgpu.conf -> /home/ilyyeees/Desktop/inverstigate/lightdm-amdgpu-prime-backup-20260325-030000/etc/X11/xorg.conf.d/20-amdgpu.conf
Backed up /etc/X11/xorg.conf.d/20-amdgpu.conf.disabled-by-gpu-fix -> /home/ilyyeees/Desktop/inverstigate/lightdm-amdgpu-prime-backup-20260325-030000/etc/X11/xorg.conf.d/20-amdgpu.conf.disabled-by-gpu-fix
Backed up /etc/prime-discrete -> /home/ilyyeees/Desktop/inverstigate/lightdm-amdgpu-prime-backup-20260325-030000/etc/prime-discrete
Backed up /usr/share/lightdm/lightdm.conf.d/90-nvidia.conf -> /home/ilyyeees/Desktop/inverstigate/lightdm-amdgpu-prime-backup-20260325-030000/usr/share/lightdm/lightdm.conf.d/90-nvidia.conf
Missing before switch: /usr/share/lightdm/lightdm.conf.d/90-nvidia.conf.disabled-by-lightdm-prime-fix

== Ensuring PRIME stays in on-demand mode ==
Current PRIME profile: on-demand

== Switching display manager back to LightDM ==

== Restoring the AMD Xorg device file ==
Restored /etc/X11/xorg.conf.d/20-amdgpu.conf from /etc/X11/xorg.conf.d/20-amdgpu.conf.disabled-by-gpu-fix

== Disabling the LightDM PRIME offload hook ==
Disabled /usr/share/lightdm/lightdm.conf.d/90-nvidia.conf

== Final state ==
/etc/X11/default-display-manager: /usr/sbin/lightdm
display-manager.service -> /usr/lib/systemd/system/lightdm.service
prime-select query: on-demand

/etc/X11/xorg.conf.d/20-amdgpu.conf
Section "Device"
    Identifier "AMD"
    Driver "amdgpu"
    Option "TearFree" "true"
EndSection

/usr/share/lightdm/lightdm.conf.d/90-nvidia.conf.disabled-by-lightdm-prime-fix
[SeatDefaults]
# Force using traditional X
type=xlocal
# Scripts to handle PRIME
display-setup-script=/sbin/prime-offload
display-stopped-script=/sbin/prime-switch

LightDM + AMDGPU hybrid fallback prepared.