Comment 0 for bug 1872159

I think this is a problem with the splash boot loader.

I have installed 20.04 to this laptop. Clean install, not an upgrade.
When booting from the install, the greeter screen is never reached if external monitors are connected at startup.
I get the spinning ubuntu logo, and nothing more. I can not change to virtual terminals.
In recovery mood, I can log in.
I am used to having such problems with Nvidia graphics is involved, but this is not the case on this laptop. It has been happily running 18.04.

External displays are recognised if they are connected after login.

Also, when I edit /etc/default/grub so that it reads
GRUB_CMDLINE_LINUX_DEFAULT=""
(that is, splash disabled)
it works fine with two external monitors attached.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.4.0-21.25-generic 5.4.27
Uname: Linux 5.4.0-21-generic x86_64
ApportVersion: 2.20.11-0ubuntu26
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Sat Apr 11 13:58:19 2020
DistUpgraded: Fresh install
DistroCodename: focal
DistroVariant: ubuntu
DkmsStatus:
 acpi-call, 1.1.0, 5.4.0-21-generic, x86_64: installed
 tp_smapi, 0.43, 5.4.0-21-generic, x86_64: installed
ExtraDebuggingInterest: Yes, including running git bisection searches
GraphicsCard:
 Intel Corporation UHD Graphics 620 [8086:5917] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Lenovo UHD Graphics 620 [17aa:225d]
InstallationDate: Installed on 2020-04-10 (0 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Beta amd64 (20200402)
MachineType: LENOVO 20L5S00F00
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-21-generic root=/dev/mapper/myvg-root ro
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/19/2020
dmi.bios.vendor: LENOVO
dmi.bios.version: N24ET56W (1.31 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20L5S00F00
dmi.board.vendor: LENOVO
dmi.board.version: Not Defined
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrN24ET56W(1.31):bd02/19/2020:svnLENOVO:pn20L5S00F00:pvrThinkPadT480:rvnLENOVO:rn20L5S00F00:rvrNotDefined:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad T480
dmi.product.name: 20L5S00F00
dmi.product.sku: LENOVO_MT_20L5_BU_Think_FM_ThinkPad T480
dmi.product.version: ThinkPad T480
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.101-1
version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.4-1ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx 20.0.4-1ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.20.7-2ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20190815-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1