Lightdm fails to start automatically (second boot after 2021-10-08 stable update)

Dear Manjaro experts

I installed the stable update 2021-10-08 pretty much as soon as I got informed about it from the package manager.
I installed it (still being on 5.13.19 kernel), rebooted - it was fine.
I then installed 5.1.4 kernel (5.13.19 not yet de-installed), rebooted - it was fine.

After working with my workstation for a few hours (without issues) I shut it down for the night and powered it on again about 12h later, when I was greeted by a “failed: light display manager failed to start” and no XFCE (automatic login).
The CLI was available, so I logged in and started the lightdm per systemctl and that worked - XFCE started up.

I am on AMD GPU and AMD CPU. All the forum posts I found so far were concerning nvidia-drivers.

Anyone an idea what might have caused it (sorry - I am not too bad with linux servers, but the graphical parts of linux are still somewhat a mystery to me)?

Thanks a lot

Additional information:
The log files /var/log/lightdm/lightdm.log

Summary

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.30.0, UID=0 PID=1609
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /var/lib/flatpak/exports/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ‘gio-vfs’
[+0.00s] DEBUG: Monitoring logind for seats
[+0.00s] DEBUG: New seat added from logind: seat0
[+0.00s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.00s] DEBUG: Seat seat0 has property CanMultiSession=no
[+0.00s] DEBUG: Seat seat0: Starting
[+0.00s] DEBUG: Seat seat0: Creating user session
[+0.00s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.00s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+0.01s] DEBUG: Seat seat0: Creating display server of type x
[+0.01s] DEBUG: Could not run plymouth --ping: Failed to execute child process “plymouth” (No such file or directory)
[+0.01s] DEBUG: Using VT 7
[+0.01s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.01s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+0.01s] DEBUG: XServer 0: Writing X server authority to /run/lightdm/root/:0
[+0.01s] DEBUG: XServer 0: Launching X Server
[+0.01s] DEBUG: Launching process 1615: /usr/bin/X :0 -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.01s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.01s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.01s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.06s] DEBUG: Seat seat0 changes active session to
[+0.96s] DEBUG: Got signal 10 from process 1615
[+0.96s] DEBUG: XServer 0: Got signal from X server :0
[+0.96s] DEBUG: XServer 0: Connecting to XServer :0
[+0.96s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+0.96s] DEBUG: Session pid=1649: Started with service ‘lightdm-autologin’, username ‘stefan’
[+0.98s] DEBUG: Session pid=1649: Authentication complete with return value 0: Success
[+0.98s] DEBUG: Seat seat0: Session authenticated, running command
[+0.98s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+0.98s] DEBUG: Session pid=1649: Running command /etc/lightdm/Xsession startxfce4
[+0.98s] DEBUG: Creating shared data directory /var/lib/lightdm-data/stefan
[+0.98s] DEBUG: Session pid=1649: Logging to .xsession-errors
[+1.00s] DEBUG: Activating VT 7
[+1.00s] DEBUG: Activating login1 session 3
[+1.00s] DEBUG: Seat seat0 changes active session to 3
[+1.00s] DEBUG: Session 3 is already active

The logfile /var/log/lightdm/lightdm.log.old

Summary

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.30.0, UID=0 PID=1423
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /var/lib/flatpak/exports/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ‘gio-vfs’
[+0.00s] DEBUG: Monitoring logind for seats
[+0.00s] DEBUG: New seat added from logind: seat0
[+0.00s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.00s] DEBUG: Seat seat0 has property CanMultiSession=no
[+0.00s] DEBUG: Seat seat0: Starting
[+0.00s] DEBUG: Seat seat0: Creating user session
[+0.00s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.00s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+0.01s] DEBUG: Seat seat0: Creating display server of type x
[+0.01s] DEBUG: Could not run plymouth --ping: Failed to execute child process “plymouth” (No such file or directory)
[+0.01s] DEBUG: Using VT 7
[+0.01s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.01s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+0.01s] DEBUG: XServer 0: Writing X server authority to /run/lightdm/root/:0
[+0.01s] DEBUG: XServer 0: Launching X Server
[+0.01s] DEBUG: Launching process 1429: /usr/bin/X :0 -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.01s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.01s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.01s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.02s] DEBUG: Process 1429 exited with return value 1
[+0.02s] DEBUG: XServer 0: X server stopped
[+0.02s] DEBUG: Releasing VT 7
[+0.02s] DEBUG: XServer 0: Removing X server authority /run/lightdm/root/:0
[+0.02s] DEBUG: Seat seat0: Display server stopped
[+0.02s] DEBUG: Seat seat0: Stopping session
[+0.02s] DEBUG: Seat seat0: Session stopped
[+0.02s] DEBUG: Seat seat0: Stopping display server, no sessions require it
[+0.02s] DEBUG: Seat seat0: Active display server stopped, starting greeter
[+0.02s] DEBUG: Seat seat0: Creating greeter session
[+0.02s] DEBUG: Seat seat0: Creating display server of type x
[+0.02s] DEBUG: Using VT 7
[+0.02s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.02s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+0.02s] DEBUG: XServer 0: Writing X server authority to /run/lightdm/root/:0
[+0.02s] DEBUG: XServer 0: Launching X Server
[+0.02s] DEBUG: Launching process 1430: /usr/bin/X :0 -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.02s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.03s] DEBUG: Process 1430 exited with return value 1
[+0.03s] DEBUG: XServer 0: X server stopped
[+0.03s] DEBUG: Releasing VT 7
[+0.03s] DEBUG: XServer 0: Removing X server authority /run/lightdm/root/:0
[+0.03s] DEBUG: Seat seat0: Display server stopped
[+0.03s] DEBUG: Seat seat0: Stopping session
[+0.03s] DEBUG: Seat seat0: Session stopped
[+0.03s] DEBUG: Seat seat0: Stopping display server, no sessions require it
[+0.03s] DEBUG: Seat seat0: Stopping; greeter display server failed to start
[+0.03s] DEBUG: Seat seat0: Stopping
[+0.03s] DEBUG: Seat seat0: Stopped
[+0.03s] DEBUG: Required seat has stopped
[+0.03s] DEBUG: Stopping display manager
[+0.03s] DEBUG: Display manager stopped
[+0.03s] DEBUG: Stopping daemon
[+0.03s] DEBUG: Exiting with return value 1

inxi -Fza

Summary
System:    Kernel: 5.14.10-1-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0 
           parameters: BOOT_IMAGE=/boot/vmlinuz-5.14-x86_64 root=UUID=b2a29984-2be3-42ea-918a-e9f10db8d4f0 rw quiet apparmor=1 
           security=apparmor udev.log_priority=3 
           Desktop: Xfce 4.16.0 tk: Gtk 3.24.29 info: xfce4-panel wm: xfwm 4.16.1 vt: 7 dm: LightDM 1.30.0 
           Distro: Manjaro Linux base: Arch Linux 
Machine:   Type: Desktop Mobo: ASRock model: X570 Taichi serial: <filter> UEFI: American Megatrends v: P2.70 date: 11/25/2019 
CPU:       Info: 12-Core model: AMD Ryzen 9 3900X bits: 64 type: MT MCP arch: Zen 2 family: 17 (23) model-id: 71 (113) 
           stepping: 0 microcode: 8701013 cache: L2: 6 MiB 
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm bogomips: 182457 
           Speed: 3348 MHz min/max: 2200/3800 MHz boost: enabled Core speeds (MHz): 1: 3348 2: 2072 3: 2196 4: 2127 5: 3603 
           6: 2046 7: 2001 8: 2199 9: 2200 10: 2197 11: 2202 12: 2200 13: 2180 14: 2199 15: 2199 16: 2200 17: 2118 18: 2201 
           19: 2198 20: 2202 21: 2200 22: 2197 23: 2199 24: 2173 
           Vulnerabilities: Type: itlb_multihit status: Not affected 
           Type: l1tf status: Not affected 
           Type: mds status: Not affected 
           Type: meltdown status: Not affected 
           Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via prctl and seccomp 
           Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer sanitization 
           Type: spectre_v2 mitigation: Full AMD retpoline, IBPB: conditional, STIBP: conditional, RSB filling 
           Type: srbds status: Not affected 
           Type: tsx_async_abort status: Not affected 
Graphics:  Device-1: Advanced Micro Devices [AMD/ATI] Navi 10 [Radeon RX 5600 OEM/5600 XT / 5700/5700 XT] 
           vendor: Sapphire Limited driver: amdgpu v: kernel bus-ID: 10:00.0 chip-ID: 1002:731f class-ID: 0300 
           Display: x11 server: X.Org 1.20.13 compositor: xfwm4 v: 4.16.1 driver: loaded: amdgpu,ati 
           unloaded: modesetting,radeon alternate: fbdev,vesa display-ID: :0.0 screens: 1 
           Screen-1: 0 s-res: 5120x1440 s-dpi: 96 s-size: 1354x381mm (53.3x15.0") s-diag: 1407mm (55.4") 
           Monitor-1: DisplayPort-0 res: 2560x1440 hz: 60 dpi: 109 size: 598x336mm (23.5x13.2") diag: 686mm (27") 
           Monitor-2: DisplayPort-1 res: 2560x1440 hz: 60 dpi: 109 size: 598x336mm (23.5x13.2") diag: 686mm (27") 
           OpenGL: renderer: AMD Radeon RX 5700 XT (NAVI10 DRM 3.42.0 5.14.10-1-MANJARO LLVM 12.0.1) v: 4.6 Mesa 21.2.3 
           direct render: Yes 
Audio:     Device-1: Advanced Micro Devices [AMD/ATI] Navi 10 HDMI Audio driver: snd_hda_intel v: kernel bus-ID: 10:00.1 
           chip-ID: 1002:ab38 class-ID: 0403 
           Device-2: Advanced Micro Devices [AMD] Starship/Matisse HD Audio vendor: ASRock driver: snd_hda_intel v: kernel 
           bus-ID: 12:00.4 chip-ID: 1022:1487 class-ID: 0403 
           Device-3: Logitech PRO X type: USB driver: hid-generic,snd-usb-audio,usbhid bus-ID: 1-4:3 chip-ID: 046d:0aaa 
           class-ID: 0300 serial: <filter> 
           Device-4: Corsair CORSAIR HS70 Pro Wireless Gaming Headset type: USB driver: hid-generic,snd-usb-audio,usbhid 
           bus-ID: 3-5:3 chip-ID: 1b1c:0a4f class-ID: 0300 
           Sound Server-1: ALSA v: k5.14.10-1-MANJARO running: yes 
           Sound Server-2: JACK v: 1.9.19 running: no 
           Sound Server-3: PulseAudio v: 15.0 running: yes 
           Sound Server-4: PipeWire v: 0.3.38 running: no 
Network:   Device-1: Intel Wi-Fi 6 AX200 driver: iwlwifi v: kernel bus-ID: 07:00.0 chip-ID: 8086:2723 class-ID: 0280 
           IF: wlp7s0 state: down mac: <filter> 
           Device-2: Intel I211 Gigabit Network vendor: ASRock driver: igb v: kernel port: f000 bus-ID: 09:00.0 
           chip-ID: 8086:1539 class-ID: 0200 
           IF: enp9s0 state: up speed: 1000 Mbps duplex: full mac: <filter> 
Bluetooth: Device-1: Intel AX200 Bluetooth type: USB driver: btusb v: 0.8 bus-ID: 3-2:2 chip-ID: 8087:0029 class-ID: e001 
           Report: rfkill ID: hci0 rfk-id: 1 state: down bt-service: enabled,running rfk-block: hardware: no software: yes 
           address: see --recommends 
Drives:    Local Storage: total: 3.64 TiB used: 964.81 GiB (25.9%) 
           SMART Message: Required tool smartctl not installed. Check --recommends 
           ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Samsung model: SSD 970 EVO Plus 1TB size: 931.51 GiB block-size: 
           physical: 512 B logical: 512 B speed: 31.6 Gb/s lanes: 4 type: SSD serial: <filter> rev: 2B2QEXM7 temp: 44.9 C 
           scheme: GPT 
           ID-2: /dev/nvme1n1 maj-min: 259:4 vendor: Samsung model: SSD 970 EVO Plus 1TB size: 931.51 GiB block-size: 
           physical: 512 B logical: 512 B speed: 31.6 Gb/s lanes: 4 type: SSD serial: <filter> rev: 2B2QEXM7 temp: 45.9 C 
           scheme: GPT 
           ID-3: /dev/sda maj-min: 8:0 vendor: Samsung model: SSD 860 EVO 2TB size: 1.82 TiB block-size: physical: 512 B 
           logical: 512 B speed: 6.0 Gb/s type: SSD serial: <filter> rev: 3B6Q scheme: GPT 
Partition: ID-1: / raw-size: 146.48 GiB size: 143.19 GiB (97.75%) used: 59.05 GiB (41.2%) fs: ext4 dev: /dev/nvme0n1p2 
           maj-min: 259:2 
           ID-2: /boot/efi raw-size: 200 MiB size: 196.9 MiB (98.45%) used: 266 KiB (0.1%) fs: vfat dev: /dev/nvme0n1p1 
           maj-min: 259:1 
           ID-3: /home raw-size: 784.83 GiB size: 771.51 GiB (98.30%) used: 80.32 GiB (10.4%) fs: ext4 dev: /dev/nvme0n1p3 
           maj-min: 259:3 
Swap:      Alert: No swap data was found. 
Sensors:   System Temperatures: cpu: 50.9 C mobo: 38.5 C gpu: amdgpu temp: 51.0 C mem: 56.0 C 
           Fan Speeds (RPM): fan-1: 849 fan-2: 642 fan-3: 975 fan-4: 498 fan-5: 604 fan-6: 0 fan-7: 0 gpu: amdgpu fan: 0 
Info:      Processes: 448 Uptime: 33m wakeups: 0 Memory: 31.29 GiB used: 3.75 GiB (12.0%) Init: systemd v: 249 tool: systemctl 
           Compilers: gcc: 11.1.0 alt: 10 clang: 12.0.1 Packages: 1727 pacman: 1698 lib: 485 flatpak: 21 snap: 8 Shell: Bash 
           v: 5.1.8 running-in: xfce4-terminal inxi: 3.3.06 

The file /var/log/Xorg.0.log.old (my first reboot today on 2021-10-11 which didnt work)

Summary
[     3.593] 
X.Org X Server 1.20.13
X Protocol Version 11, Revision 0
[     3.593] Build Operating System: Linux Manjaro Linux
[     3.593] Current Operating System: Linux stefan-desktop 5.14.10-1-MANJARO #1 SMP PREEMPT Thu Oct 7 06:43:34 UTC 2021 x86_64
[     3.593] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.14-x86_64 root=UUID=b2a29984-2be3-42ea-918a-e9f10db8d4f0 rw quiet apparmor=1 security=apparmor udev.log_priority=3
[     3.593] Build Date: 24 August 2021  10:21:29AM
[     3.593]  
[     3.593] Current version of pixman: 0.40.0
[     3.593] 	Before reporting problems, check http://wiki.x.org
	to make sure that you have the latest version.
[     3.593] Markers: (--) probed, (**) from config file, (==) default setting,
	(++) from command line, (!!) notice, (II) informational,
	(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[     3.593] (==) Log file: "/var/log/Xorg.0.log", Time: Mon Oct 11 08:14:40 2021
[     3.593] (==) Using config directory: "/etc/X11/xorg.conf.d"
[     3.593] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[     3.593] (==) ServerLayout "layout"
[     3.593] (==) No screen section available. Using defaults.
[     3.593] (**) |-->Screen "Default Screen Section" (0)
[     3.593] (**) |   |-->Monitor "<default monitor>"
[     3.593] (==) No monitor specified for screen "Default Screen Section".
	Using a default monitor configuration.
[     3.593] (==) Automatically adding devices
[     3.593] (==) Automatically enabling devices
[     3.593] (==) Automatically adding GPU devices
[     3.593] (==) Automatically binding GPU devices
[     3.593] (==) Max clients allowed: 256, resource mask: 0x1fffff
[     3.593] (WW) The directory "/usr/share/fonts/OTF" does not exist.
[     3.593] 	Entry deleted from font path.
[     3.593] (WW) The directory "/usr/share/fonts/Type1" does not exist.
[     3.593] 	Entry deleted from font path.
[     3.593] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/100dpi".
[     3.593] 	Entry deleted from font path.
[     3.593] 	(Run 'mkfontdir' on "/usr/share/fonts/100dpi").
[     3.593] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/75dpi".
[     3.593] 	Entry deleted from font path.
[     3.593] 	(Run 'mkfontdir' on "/usr/share/fonts/75dpi").
[     3.593] (==) FontPath set to:
	/usr/share/fonts/misc,
	/usr/share/fonts/TTF
[     3.593] (==) ModulePath set to "/usr/lib/xorg/modules"
[     3.593] (II) The server relies on udev to provide the list of input devices.
	If no devices become available, reconfigure udev or disable AutoAddDevices.
[     3.593] (II) Module ABI versions:
[     3.593] 	X.Org ANSI C Emulation: 0.4
[     3.593] 	X.Org Video Driver: 24.1
[     3.593] 	X.Org XInput driver : 24.1
[     3.593] 	X.Org Server Extension : 10.0
[     3.594] (++) using VT number 7

[     3.594] (II) systemd-logind: logind integration requires -keeptty and -keeptty was not provided, disabling logind integration
[     3.596] (--) PCI:*(16@0:0:0) 1002:731f:1da2:e409 rev 193, Mem @ 0xe0000000/268435456, 0xf0000000/2097152, 0xfcb00000/524288, I/O @ 0x0000e000/256, BIOS @ 0x????????/131072
[     3.596] (WW) Open ACPI failed (/var/run/acpid.socket) (No such file or directory)
[     3.596] (II) LoadModule: "glx"
[     3.596] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
[     3.597] (II) Module glx: vendor="X.Org Foundation"
[     3.597] 	compiled for 1.20.13, module version = 1.0.0
[     3.597] 	ABI class: X.Org Server Extension, version 10.0
[     3.597] (==) Matched ati as autoconfigured driver 0
[     3.597] (==) Matched modesetting as autoconfigured driver 1
[     3.597] (==) Matched fbdev as autoconfigured driver 2
[     3.597] (==) Matched vesa as autoconfigured driver 3
[     3.597] (==) Assigned the driver to the xf86ConfigLayout
[     3.597] (II) LoadModule: "ati"
[     3.597] (II) Loading /usr/lib/xorg/modules/drivers/ati_drv.so
[     3.597] (II) Module ati: vendor="X.Org Foundation"
[     3.597] 	compiled for 1.20.8, module version = 19.1.0
[     3.597] 	Module class: X.Org Video Driver
[     3.597] 	ABI class: X.Org Video Driver, version 24.1
[     3.597] (II) LoadModule: "radeon"
[     3.597] (II) Loading /usr/lib/xorg/modules/drivers/radeon_drv.so
[     3.597] (II) Module radeon: vendor="X.Org Foundation"
[     3.597] 	compiled for 1.20.8, module version = 19.1.0
[     3.597] 	Module class: X.Org Video Driver
[     3.597] 	ABI class: X.Org Video Driver, version 24.1
[     3.597] (II) LoadModule: "modesetting"
[     3.597] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[     3.597] (II) Module modesetting: vendor="X.Org Foundation"
[     3.597] 	compiled for 1.20.13, module version = 1.20.13
[     3.597] 	Module class: X.Org Video Driver
[     3.597] 	ABI class: X.Org Video Driver, version 24.1
[     3.597] (II) LoadModule: "fbdev"
[     3.597] (WW) Warning, couldn't open module fbdev
[     3.597] (EE) Failed to load module "fbdev" (module does not exist, 0)
[     3.597] (II) LoadModule: "vesa"
[     3.597] (WW) Warning, couldn't open module vesa
[     3.597] (EE) Failed to load module "vesa" (module does not exist, 0)
[     3.597] (II) RADEON: Driver for ATI/AMD Radeon chipsets:
	ATI Radeon Mobility X600 (M24), ATI FireMV 2400,
	ATI Radeon Mobility X300 (M24), ATI FireGL M24 GL,
	ATI Radeon X600 (RV380), ATI FireGL V3200 (RV380),
	ATI Radeon IGP320 (A3), ATI Radeon IGP330/340/350 (A4),
	ATI Radeon 9500, ATI Radeon 9600TX, ATI FireGL Z1, ATI Radeon 9800SE,
	ATI Radeon 9800, ATI FireGL X2, ATI Radeon 9600, ATI Radeon 9600SE,
	ATI Radeon 9600XT, ATI FireGL T2, ATI Radeon 9650, ATI FireGL RV360,
	ATI Radeon 7000 IGP (A4+), ATI Radeon 8500 AIW,
	ATI Radeon IGP320M (U1), ATI Radeon IGP330M/340M/350M (U2),
	ATI Radeon Mobility 7000 IGP, ATI Radeon 9000/PRO, ATI Radeon 9000,
	ATI Radeon X800 (R420), ATI Radeon X800PRO (R420),
	ATI Radeon X800SE (R420), ATI FireGL X3 (R420),
	ATI Radeon Mobility 9800 (M18), ATI Radeon X800 SE (R420),
	ATI Radeon X800XT (R420), ATI Radeon X800 VE (R420),
	ATI Radeon X850 (R480), ATI Radeon X850 XT (R480),
	ATI Radeon X850 SE (R480), ATI Radeon X850 PRO (R480),
	ATI Radeon X850 XT PE (R480), ATI Radeon Mobility M7,
	ATI Mobility FireGL 7800 M7, ATI Radeon Mobility M6,
	ATI FireGL Mobility 9000 (M9), ATI Radeon Mobility 9000 (M9),
	ATI Radeon 9700 Pro, ATI Radeon 9700/9500Pro, ATI FireGL X1,
	ATI Radeon 9800PRO, ATI Radeon 9800XT,
	ATI Radeon Mobility 9600/9700 (M10/M11),
	ATI Radeon Mobility 9600 (M10), ATI Radeon Mobility 9600 (M11),
	ATI FireGL Mobility T2 (M10), ATI FireGL Mobility T2e (M11),
	ATI Radeon, ATI FireGL 8700/8800, ATI Radeon 8500, ATI Radeon 9100,
	ATI Radeon 7500, ATI Radeon VE/7000, ATI ES1000,
	ATI Radeon Mobility X300 (M22), ATI Radeon Mobility X600 SE (M24C),
	ATI FireGL M22 GL, ATI Radeon X800 (R423), ATI Radeon X800PRO (R423),
	ATI Radeon X800LE (R423), ATI Radeon X800SE (R423),
	ATI Radeon X800 XTP (R430), ATI Radeon X800 XL (R430),
	ATI Radeon X800 SE (R430), ATI Radeon X800 (R430),
	ATI FireGL V7100 (R423), ATI FireGL V5100 (R423),
	ATI FireGL unknown (R423), ATI Mobility FireGL V5000 (M26),
	ATI Mobility Radeon X700 XL (M26), ATI Mobility Radeon X700 (M26),
	ATI Radeon X550XTX, ATI Radeon 9100 IGP (A5),
	ATI Radeon Mobility 9100 IGP (U3), ATI Radeon XPRESS 200,
	ATI Radeon XPRESS 200M, ATI Radeon 9250, ATI Radeon 9200,
	ATI Radeon 9200SE, ATI FireMV 2200, ATI Radeon X300 (RV370),
	ATI Radeon X600 (RV370), ATI Radeon X550 (RV370),
	ATI FireGL V3100 (RV370), ATI FireMV 2200 PCIE (RV370),
	ATI Radeon Mobility 9200 (M9+), ATI Mobility Radeon X800 XT (M28),
	ATI Mobility FireGL V5100 (M28), ATI Mobility Radeon X800 (M28),
	ATI Radeon X850, ATI unknown Radeon / FireGL (R480),
	ATI Radeon X800XT (R423), ATI FireGL V5000 (RV410),
	ATI Radeon X700 XT (RV410), ATI Radeon X700 PRO (RV410),
	ATI Radeon X700 SE (RV410), ATI Radeon X700 (RV410),
	ATI Radeon X1800, ATI Mobility Radeon X1800 XT,
	ATI Mobility Radeon X1800, ATI Mobility FireGL V7200,
	ATI FireGL V7200, ATI FireGL V5300, ATI Mobility FireGL V7100,
	ATI FireGL V7300, ATI FireGL V7350, ATI Radeon X1600, ATI RV505,
	ATI Radeon X1300/X1550, ATI Radeon X1550, ATI M54-GL,
	ATI Mobility Radeon X1400, ATI Radeon X1550 64-bit,
	ATI Mobility Radeon X1300, ATI Radeon X1300, ATI FireGL V3300,
	ATI FireGL V3350, ATI Mobility Radeon X1450,
	ATI Mobility Radeon X2300, ATI Mobility Radeon X1350,
	ATI FireMV 2250, ATI Radeon X1650, ATI Mobility FireGL V5200,
	ATI Mobility Radeon X1600, ATI Radeon X1300 XT/X1600 Pro,
	ATI FireGL V3400, ATI Mobility FireGL V5250,
	ATI Mobility Radeon X1700, ATI Mobility Radeon X1700 XT,
	ATI FireGL V5200, ATI Radeon X2300HD, ATI Mobility Radeon HD 2300,
	ATI Radeon X1950, ATI Radeon X1900, ATI AMD Stream Processor,
	ATI RV560, ATI Mobility Radeon X1900, ATI Radeon X1950 GT, ATI RV570,
	ATI FireGL V7400, ATI Radeon 9100 PRO IGP,
	ATI Radeon Mobility 9200 IGP, ATI Radeon X1200, ATI RS740,
	ATI RS740M, ATI Radeon HD 2900 XT, ATI Radeon HD 2900 Pro,
	ATI Radeon HD 2900 GT, ATI FireGL V8650, ATI FireGL V8600,
	ATI FireGL V7600, ATI Radeon 4800 Series, ATI Radeon HD 4870 x2,
	ATI Radeon HD 4850 x2, ATI FirePro V8750 (FireGL),
	ATI FirePro V7760 (FireGL), ATI Mobility RADEON HD 4850,
	ATI Mobility RADEON HD 4850 X2, ATI FirePro RV770,
	AMD FireStream 9270, AMD FireStream 9250, ATI FirePro V8700 (FireGL),
	ATI Mobility RADEON HD 4870, ATI Mobility RADEON M98,
	ATI FirePro M7750, ATI M98, ATI Mobility Radeon HD 4650,
	ATI Radeon RV730 (AGP), ATI Mobility Radeon HD 4670,
	ATI FirePro M5750, ATI RV730XT [Radeon HD 4670], ATI RADEON E4600,
	ATI Radeon HD 4600 Series, ATI RV730 PRO [Radeon HD 4650],
	ATI FirePro V7750 (FireGL), ATI FirePro V5700 (FireGL),
	ATI FirePro V3750 (FireGL), ATI Mobility Radeon HD 4830,
	ATI Mobility Radeon HD 4850, ATI FirePro M7740, ATI RV740,
	ATI Radeon HD 4770, ATI Radeon HD 4700 Series, ATI RV610,
	ATI Radeon HD 2400 XT, ATI Radeon HD 2400 Pro,
	ATI Radeon HD 2400 PRO AGP, ATI FireGL V4000, ATI Radeon HD 2350,
	ATI Mobility Radeon HD 2400 XT, ATI Mobility Radeon HD 2400,
	ATI RADEON E2400, ATI FireMV 2260, ATI RV670, ATI Radeon HD3870,
	ATI Mobility Radeon HD 3850, ATI Radeon HD3850,
	ATI Mobility Radeon HD 3850 X2, ATI Mobility Radeon HD 3870,
	ATI Mobility Radeon HD 3870 X2, ATI Radeon HD3870 X2,
	ATI FireGL V7700, ATI Radeon HD3690, AMD Firestream 9170,
	ATI Radeon HD 4550, ATI Radeon RV710, ATI Radeon HD 4350,
	ATI Mobility Radeon 4300 Series, ATI Mobility Radeon 4500 Series,
	ATI FirePro RG220, ATI Mobility Radeon 4330, ATI RV630,
	ATI Mobility Radeon HD 2600, ATI Mobility Radeon HD 2600 XT,
	ATI Radeon HD 2600 XT AGP, ATI Radeon HD 2600 Pro AGP,
	ATI Radeon HD 2600 XT, ATI Radeon HD 2600 Pro, ATI Gemini RV630,
	ATI Gemini Mobility Radeon HD 2600 XT, ATI FireGL V5600,
	ATI FireGL V3600, ATI Radeon HD 2600 LE,
	ATI Mobility FireGL Graphics Processor, ATI Radeon HD 3470,
	ATI Mobility Radeon HD 3430, ATI Mobility Radeon HD 3400 Series,
	ATI Radeon HD 3450, ATI Radeon HD 3430, ATI FirePro V3700,
	ATI FireMV 2450, ATI Radeon HD 3600 Series, ATI Radeon HD 3650 AGP,
	ATI Radeon HD 3600 PRO, ATI Radeon HD 3600 XT,
	ATI Mobility Radeon HD 3650, ATI Mobility Radeon HD 3670,
	ATI Mobility FireGL V5700, ATI Mobility FireGL V5725,
	ATI Radeon HD 3200 Graphics, ATI Radeon 3100 Graphics,
	ATI Radeon HD 3300 Graphics, ATI Radeon 3000 Graphics, SUMO, SUMO2,
	ATI Radeon HD 4200, ATI Radeon 4100, ATI Mobility Radeon HD 4200,
	ATI Mobility Radeon 4100, ATI Radeon HD 4290, ATI Radeon HD 4250,
	AMD Radeon HD 6310 Graphics, AMD Radeon HD 6250 Graphics,
	AMD Radeon HD 6300 Series Graphics,
	AMD Radeon HD 6200 Series Graphics, PALM, CYPRESS,
	ATI FirePro (FireGL) Graphics Adapter, AMD Firestream 9370,
	AMD Firestream 9350, ATI Radeon HD 5800 Series,
	ATI Radeon HD 5900 Series, ATI Mobility Radeon HD 5800 Series,
	ATI Radeon HD 5700 Series, ATI Radeon HD 6700 Series,
	ATI Mobility Radeon HD 5000 Series, ATI Mobility Radeon HD 5570,
	ATI Radeon HD 5670, ATI Radeon HD 5570, ATI Radeon HD 5500 Series,
	REDWOOD, ATI Mobility Radeon Graphics, CEDAR, ATI FirePro 2270,
	ATI Radeon HD 5450, CAYMAN, AMD Radeon HD 6900 Series,
	AMD Radeon HD 6900M Series, Mobility Radeon HD 6000 Series, BARTS,
	AMD Radeon HD 6800 Series, AMD Radeon HD 6700 Series, TURKS, CAICOS,
	ARUBA, TAHITI, PITCAIRN, VERDE, OLAND, HAINAN, BONAIRE, KABINI,
	MULLINS, KAVERI, HAWAII
[     3.598] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[     3.598] (EE) open /dev/dri/card0: No such file or directory
[     3.598] (WW) Falling back to old probe method for modesetting
[     3.598] (EE) open /dev/dri/card0: No such file or directory
[     3.598] (EE) Screen 0 deleted because of no matching config section.
[     3.598] (II) UnloadModule: "modesetting"
[     3.598] (EE) Device(s) detected, but none match those in the config file.
[     3.598] (EE) 
Fatal server error:
[     3.598] (EE) no screens found(EE) 
[     3.598] (EE) 
Please consult the The X.Org Foundation support 
	 at http://wiki.x.org
 for help. 
[     3.598] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
[     3.598] (EE) 
[     3.598] (EE) Server terminated with error (1). Closing log file.

Hello @scheuri :wink:

Such things could happen on cold boots. In general it is a timing issue… so Manjaro boots that fast with your nvme, so that the gpu cannot keep up (gpu modules normally load on request) and lightdm does not wait long enough.

Workaround is adding the driver to the initramfs for early loading. So in your case:

Replace MODULES=() with:

# the order of the modules matters
MODULES=(amdgpu radeon)

at /etc/mkinitcpio.conf

Then run sudo mkinitcpio -P to update the initramfs.

Thank you @megavolt
Much appreciated!
I will test it over the upcoming days, thanks again!

I changed /etc/mkinitcpio.conf from

# the order of the modules matters
MODULES=""

to

# the order of the modules matters
MODULES="amdgpu radeon"

However, from four reboots so far, only one was directly going into lightdm/XFCE while the other three failed (and I had to login into CLI and start lightdm myself).

What is strange:
The original MODULES section was empty and that was pointed out by two doublequotes with no data in between, but in the comments for that section the examples are using brackets (such as ()) rather than doublequotes.

Will try it with brackets and see what happens, but I find this kinda strange…to describe a parameter being empty with special chars while it needs other special chars when its not empty…

Your not allone :sob: i also have a fast nvme and sometimes the boot into GUI fails without visible reason. Lightdm shows restarts, and moste times succeeds after a few tries. But sometimes even xorg fails …