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I have an external monitor(Dell P2210) plugged into my Dell Latitude E5570 laptop via VGA. It runs ubuntu 18.04 for a few months without a problem. The recent kernel update(4.15-0-43 to 4.15-0-44 I believe) seems to break the external monitor connection.

The problem is like this:

  • At a fresh startup, the laptop built-in screen turns black after the grub menu, external monitor didn't detect signal & remains black.

  • Switched back to kernel 4.15-0-43, Everything works as normal as the past 2 years. I upgraded from ubuntu16.04 to 18.04 a few months back but that didn't cause any issue.

  • In the latest kernel 4.15-0-44, I am able to get the external working by plugging it in after the laptop is completely booted up. but after the laptop gets into sleep mode(suspend), I'm unable to wake it up, the built-in screen and external monitor all remain black.

Now I'm pretty sure the issue lies in the latest kernel update, how do I further narrow down & fix the issue in the latest kernel?

TC Zhang
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  • have you tryed manually upgrading the kernal https://askubuntu.com/questions/119080/how-to-update-kernel-to-the-latest-mainline-version-without-any-distro-upgrade and look for @WinEunuuchs2Unix – Budget Tech Jan 31 '19 at 05:09
  • Can confirm the issue with 4.15.0-44-generic kernel. As a workaround, you can dock your laptop after logging in. – Dorian Marchal Jan 31 '19 at 08:20
  • I'm having the same issue but kernel is 4.15.0-45-generic -- I can dock after logging in but it also happens when my computer sleeps. – Amanda Jan 31 '19 at 17:41
  • Hi, all, This bug seems to be noticed by the ubuntu security team https://usn.ubuntu.com/3871-2/ and has been fixed in linux-image-4.15.0-45-generic - 4.15.0-45.48. I can't update to 4.15.0-45.48 for now so I'm unable to confirm the fix. – TC Zhang Feb 06 '19 at 00:12
  • fixed by upgrading to 4.15.0-45 – TC Zhang Feb 07 '19 at 00:32

0 Answers0