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

Sat Dec 30 23:27:34 UTC 2023

Lubuntu 23.10 installed:

I tested Lubuntu 23.10 which is installed in UEFI mode in the HP Probook
640 G4 (internal ). This matches what was described in the original bug
report.

1-3. Cold-booted with the external screen connected all the time. It
worked well.

4. Rebooted with the external screen connected all the time. It worked
well.

-o-

I updated && upgraded Lubuntu.

5. Cold-booted with the external screen connected all the time. It
worked well.

6. Rebooted with the external screen connected all the time. It worked
well.

-o-

Why are things working better now?

a. Maybe the file system or some memory locations was corrupted after
the previous testing and brutal shutdowns between various attempts with
Lubuntu Noble live before testing the installed system.

b. Maybe the power voltage was a bit low. I had not used the computer
for months, and I was/am charging it via USB-C.

c. Maybe the HDMI connection was a bit oxidized and flaky. After
plugging and replugging several times, the connection might be cleaned
from oxides.

Lubuntu Noble Live:

7. I plugged in Lubuntu Noble live via USB, made by cloning, and had a
glitch (nothing on any of the screens except a white underscore on the
internal screen). I disconnected the external screen, the system
recovered, and I could connect the external screen again and things
worked.

d. I suspect that I pressed F9 for a temporary menu too late, and caused
the glitch. Maybe this caused some of the original glitches too.

8,9. Cold-booted with the external screen connected all the time. It
worked well after alt+tab.

10. Rebooted with the external screen connected all the time. It worked
well after alt+tab.

11,12. I plugged in Lubuntu Noble persistent live via USB, made by dus-
iso2usb (grub-n-iso method). It worked well too after alt+tab.

-o-

So, things look more consistent (less flaky) now, at least partly
because I can repeat the tests in a more consistent way.

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https://bugs.launchpad.net/bugs/2047456

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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