Apolgies, I logged in with nomodeset in GRUB with basic graphics to be able to boot successfully in order to perform further troubleshooting. Please see attached file showing the full hardware configuration of my machine. I am also running Fedora and Kali on this triple-boot machine with Ubuntu, each of which are installed on their own 2TB SSD. Both Fedora and Kali boot fine with my dual-monitor set-up. Please advise if you need any other information or boot logs. Many thanks.
** Attachment added: "Full Hardware Config" https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/2128883/+attachment/5919892/+files/my_hardware.txt -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/2128883 Title: linux-firmware 20240318.git3b128b60-0ubuntu2.19 causes black screen on login with dual 4K monitors at 200% scaling on Wayland (AMD GPU) Status in linux-firmware package in Ubuntu: Confirmed Status in mutter package in Ubuntu: Incomplete Bug description: Summary: After automatic update from linux-firmware version .17 to .19 on October 17, 2025, Ubuntu 24.04 displays black screen on login when using dual LG ULTRAFINE 4K monitors with 200% fractional scaling on Wayland. The issue specifically occurs when GNOME/GDM attempts to initialize displays at 200% scaling during boot. Hardware: - CPU: AMD Ryzen 16-core - GPU: AMD (integrated graphics) - Monitors: 2x LG ULTRAFINE 4K (3840x2160) via DisplayPort - Display Server: Wayland - Desktop: GNOME Steps to Reproduce: 1. Have dual 4K monitors configured at 200% fractional scaling 2. Update linux-firmware from .17 to .19 3. Save display configuration at 200% scaling 4. Reboot 5. Attempt to login Expected Result: Desktop should load normally with both monitors displaying correctly at 200% scaling Actual Result: Black screen after login when monitors.xml contains 200% scaling configuration Key Diagnostic Findings: - Deleting ~/.config/monitors.xml allows login at 100% default scaling - Changing to 200% scaling AFTER login works perfectly - Problem only occurs when GDM/GNOME loads 200% scaling during boot initialization - Rebooting after setting 200% recreates the black screen issue - This is a boot-time initialization bug, not a runtime scaling bug Workaround: Deleting ~/.config/monitors.xml before each login allows access, but requires manual reconfiguration to 200% each session (unsustainable for daily use) Fix: Downgrading to linux-firmware=20240318.git3b128b60-0ubuntu2.17 resolves the issue completely. All scaling levels work correctly with firmware .17. Additional Information: - Wayland is required for this hardware setup (X11 has display issues with dual 4K monitors even on firmware .17) - Single monitor configuration was not tested - Issue appeared immediately after firmware update on Oct 17, 2025 - Firmware .17 works perfectly with Wayland + dual 4K + 200% scaling at all times (boot and runtime) - Bug is specific to boot-time display initialization with 200% fractional scaling in firmware .19 System Information: - Ubuntu Version: 24.04.3 LTS - linux-firmware installed: 20240318.git3b128b60-0ubuntu2.17 (working - currently held) - linux-firmware candidate: 20240318.git3b128b60-0ubuntu2.19 (broken - causes black screen) ProblemType: Bug DistroRelease: Ubuntu 24.04 Package: linux-firmware 20240318.git3b128b60-0ubuntu2.17 ProcVersionSignature: Ubuntu 6.14.0-33.33~24.04.1-generic 6.14.11 Uname: Linux 6.14.0-33-generic x86_64 ApportVersion: 2.28.1-0ubuntu3.8 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: joe 2802 F.... wireplumber /dev/snd/controlC0: joe 2802 F.... wireplumber /dev/snd/seq: joe 2797 F.... pipewire CRDA: N/A CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Sat Oct 18 10:25:24 2025 Dependencies: firmware-sof-signed 2023.12.1-1ubuntu1.10 InstallationDate: Installed on 2025-10-15 (3 days ago) InstallationMedia: Ubuntu 24.04.3 LTS "Noble Numbat" - Release amd64 (20250805.1) MachineType: ASUS System Product Name ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> ProcFB: 0 amdgpudrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.14.0-33-generic root=UUID=50126da2-dd87-4955-8708-1ecb4482ba78 ro quiet splash RelatedPackageVersions: linux-restricted-modules-6.14.0-33-generic N/A linux-backports-modules-6.14.0-33-generic N/A linux-firmware 20240318.git3b128b60-0ubuntu2.17 RfKill: 0: phy0: Wireless LAN Soft blocked: no Hard blocked: no SourcePackage: linux-firmware UpgradeStatus: No upgrade log present (probably fresh install) acpidump: Error: command ['pkexec', '/usr/share/apport/dump_acpi_tables.py'] failed with exit code 126: Error executing command as another user: Request dismissed dmi.bios.date: 07/14/2025 dmi.bios.release: 10.78 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1078 dmi.board.asset.tag: Default string dmi.board.name: ROG STRIX B850-A GAMING WIFI dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Default string dmi.chassis.type: 3 dmi.chassis.vendor: Default string dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1078:bd07/14/2025:br10.78:svnASUS:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnROGSTRIXB850-AGAMINGWIFI:rvrRev1.xx:cvnDefaultstring:ct3:cvrDefaultstring:skuSKU: dmi.product.family: To be filled by O.E.M. dmi.product.name: System Product Name dmi.product.sku: SKU dmi.product.version: System Version dmi.sys.vendor: ASUS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/2128883/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
