[Bug 2047456] Re: Installed Lubuntu Mantic and Noble are flaky with two screens

[sudodus]

After today's tests I think I understand more about the buggy behaviour
in the Toshiba Satellite Pro C850-19W, when two screens are connected,
the internal one plus an external screen via HDMI.

I tested the installed Lubuntu Noble system when the SSD was connected
via a USB to SATA adapter. And it worked as it should all the way, also
when the external screen was connected all the time including cold-boot
and reboot.

I did some more tests this time by putting various SSDs inside the
Toshiba, with a cloned live Lubuntu Noble system (standard with grub
2.12~rc), and a persistent live Lubuntu Noble system and an installed
Ubuntu Server Kinetic (with grub 2.0.6). And it seems that whatever
operating system is in the internal drive, it will not even get to the
grub menu in BIOS mode, when the external screen in connected.

-o-

I should have tested this earlier, anyway now I think that there is a
bug in the UEFI/BIOS system of the Toshiba, not a bug in grub or Ubuntu.

However, the original problem exists, that causes the flaky behaviour in
UEFI mode in the HP Probook 640 G4. So I will re-focus on that problem
and see if things can be made stable (repeatable).

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Title:
  Installed Lubuntu Mantic and Noble are flaky with two screens

Status in grub2 package in Ubuntu:
  New
Status in lxqt-session package in Ubuntu:
  New

Bug description:
  Tested in an HP Probook 640 G4 with

  - Intel i5-8250U CPU
  - Intel 'UHD Graphics 6'
  - built-in resolution 1366x768

  connected to an old Samsung monitor with 1920x1080 resolution. The
  extermal screen is connected via HDMI (a HDMI to HDMI cable).

  It works smoothly when booted as usual (with only the internal
  screen). After testing Lubuntu Noble live, when booting with the
  external screen connected, it failed to show anything (nothing on any
  of the screens except a white underscore on the internal screen).
  Alt+tab did not help.

  I rebooted brutally with ctrl+alt+delete, disconnected the external
  screen and things worked well. When logged in, I cnnnected the
  external screen, and then things worked as expected. I had the correct
  background and could use both screens. So in order to check if it was
  a temporary glitch, I rebooted and cold booted several times:

  1. I prepared for making a separate bug report for problems with 2
  screens in Lubuntu 23.10. And it worked, when cold booted, also when
  the external screen is connected. Maybe some bad state in some
  electronic component(s) of the system was not cleared by the brutal
  reboot (ctrl+alt+delete) after the failure with Lubuntu Noble live.

  I repeated reboot and cold boot a few times to see if things continue
  to work well.

  2. It worked again after reboot

  3. It failed like the first time after 'correct shutdown via the menu'
  and cold boot after a few seconds.

  4. It worked well after brutal reboot (ctrl+alt+delete).

  5. It failed like the first time after 'correct shutdown via the menu'
  and cold boot after one minute (so 'colder' than the previous cold
  boot).

  6. It worked well when cold booted with the external monitor connected
  but turned off.

  7. It worked well when cold booted with the external monitor connected
  but turned off (again), When logged in, I turned on the extermal
  screen and it showed what it should show.

  8. It worked well when cold booted with the external monitor connected
  but turned off (again), When logged in, I turned on the extermal
  screen and it showed what it should show.

  9,10. It failed when I tried to edit the grub menu with 'e'. It booted
  without any command to boot (and it happened twice).

  11. It kind of worked, when I booted in recovery mode, but only the
  internal screen was active.

  12. It worked well when cold booted into normal mode with the external
  screenconnected and turned on.

  13. It worked well when cold booted with the external monitor
  connected but turned off, When logged in, I turned on the extermal
  screen and it showed what it should show.

  So I would say that the function is flaky with two screens connected
  and the external one turned on at boot.

  -o-

  Please notice that the system works now, with both screens. I am not
  able to create a bug report when it fails, because there is only an
  underscore on the internal screen and nothing on the external one.

  Please advice how to create a useful log file to upload (for example
  by booting without 'quiet splash', and what log file should I look for
  and upload)!

  ProblemType: Bug
  DistroRelease: Ubuntu 23.10
  Package: lxqt-session 1.3.0-0ubuntu4
  ProcVersionSignature: Ubuntu 6.5.0-10.10-generic 6.5.3
  Uname: Linux 6.5.0-10-generic x86_64
  ApportVersion: 2.27.0-0ubuntu5
  Architecture: amd64
  CasperMD5CheckResult: unknown
  CurrentDesktop: LXQt
  Date: Tue Dec 26 21:17:14 2023
  InstallationDate: Installed on 2023-10-21 (66 days ago)
  InstallationMedia: Lubuntu 23.10 "Mantic Minotaur" - Release amd64 (20231010)
  SourcePackage: lxqt-session
  UpgradeStatus: No upgrade log present (probably fresh install)

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