Ubuntu Studio 24.04: Plymouth graphical splash screen not working

[Lassi]

Plymouth graphical splash screen is not working at boot up, there is only text splash shown.
At shutddwn graphical splash is shown.

Kernel: 6.8.0-38-lowlatency

Based on dmesg, the 'amdgpu' driver is loaded as late as 10..16 seconds after the boot has started, which seems to be too late for Plymouth to show the graphical splash.

Not sure if "systemd modprobe drm" is responsible for getting amdgpu loaded eventually, but also that is starting quite late in the process.

Comparing amdgpu load time to for example on openSUSE Tumbleweed on the same PC, it takes 4..5 seconds, so 6..11 seconds less than on Ubuntu!

[Lassi (lassi-vaatamoinen)]

This is a Plymouth debug log on one of the boots. On this particular boot, 'amdgpu' traces were shown at 16 seconds time in the boot.

[Lassi (lassi-vaatamoinen)]

> Kernel: 6.8.0-38-lowlatency

Also happens with the latest kernel version 6.8.0-39-lowlatency

[Lassi (lassi-vaatamoinen)]

I got the Plymouth splash showing by:

1. change /etc/initramfs-tools/initramfs.conf: MODULES=most -> MODULES=dep
2. update-initramfs -u -k all

Now amdgpu driver is loaded at about 6.0 seconds into the boot.

Not sure which it should be in reality, but 'man initramfs.conf' says:

- 'most' adds most file system, all ata, sata, scsi and usb driver
- 'dep' tries to guess which modules are necessary for the running box and only adds those
  modules

So 'most' would not be enough in this case. Or is there some more generic fix for this?

[Benjamin Drung (bdrung)]

Probably related change:

initramfs-tools (0.142ubuntu23) noble; urgency=medium

  [ Daniel van Vugt ]
  * hooks/framebuffer: Only add simple/tiny framebuffer drivers. This is to
    limit the size of initrd when FRAMEBUFFER=y is soon enabled for desktop
    installations (LP: #1970069, #1869655).

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.