How to fix Ubuntu 20.04 upgrade 5.8.0-

I have the dell xps laptop. It was delivered with Windows 10, but I wiped that to install Ubuntu 18.04 which was fine. Last year, I did the upgrade to ubuntu 20.04. It worked pretty well except for a lot of messages on shutdown about devices not disconnecting. Different messages sometimes. When starting, there was always the disk check.

Today, I did "apt upgrade", there were 42 upgrades. This is after being up to date with updates and upgrades yesterday. So, 42 new updates in the past day... seemed high in retrospect. Now, I cannot boot normally into my OS. I get the encryption password screen, but after that just hangs with Dell and Ubuntu logo.

Hard reboot, esc, I get to a boot page. My choices are Ubuntu, with Linux 5.8.0-34 generic Ubuntu, with Linux 5.8.0-34 generic (recovery) Ubuntu, with Linux 5.4.0-59 generic Ubuntu, with Linux 5.4.0-59 generic (recovery)

If I boot with 5.4.0-59 generic, I can get in and everything looks the same as before. So, that is my workaround in the meantime.

Solution 1:

I can also confirm that Ubuntu 20.04.1 upgraded to Linux 5.8.0-34.

$ cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04.1 LTS (Focal Fossa)"
...

$ inxi -r
Repos:     Active apt repos in: /etc/apt/sources.list 
           1: deb http://hr.archive.ubuntu.com/ubuntu/ focal main restricted
           2: deb http://hr.archive.ubuntu.com/ubuntu/ focal-updates main restricted
           3: deb http://hr.archive.ubuntu.com/ubuntu/ focal universe
           4: deb http://hr.archive.ubuntu.com/ubuntu/ focal-updates universe
           5: deb http://hr.archive.ubuntu.com/ubuntu/ focal multiverse
           6: deb http://hr.archive.ubuntu.com/ubuntu/ focal-updates multiverse
           7: deb http://hr.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
           8: deb http://archive.canonical.com/ubuntu focal partner
           9: deb http://security.ubuntu.com/ubuntu focal-security main restricted universe multiverse

In /var/log/apt/term.log I can find the following:

Selecting previously unselected package linux-image-5.8.0-34-generic.
Preparing to unpack .../46-linux-image-5.8.0-34-generic_5.8.0-34.37~20.04.2_amd64.deb ...
Unpacking linux-image-5.8.0-34-generic (5.8.0-34.37~20.04.2) ...

apt-cache shows the following about the new kernel package:

$ apt-cache showpkg linux-image-5.8.0-34-generic
Package: linux-image-5.8.0-34-generic
Versions: 
5.8.0-34.37~20.04.2 (/var/lib/apt/lists/hr.archive.ubuntu.com_ubuntu_dists_focal-updates_main_binary-amd64_Packages) (/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_focal-security_main_binary-amd64_Packages) (/var/lib/dpkg/status)
...

So, it seems the new kernel came from an official repository. See also: https://packages.ubuntu.com/focal/linux-image-5.8.0-34-generic https://packages.ubuntu.com/focal-updates/linux-image-5.8.0-34-generic

My problem is that the Ubuntu desktop environment (GNOME) fails to start after the Linux kernel upgrade. With Linux 5.4.0-59-generic it works fine.

As suggested by guiverc I removed support for HWE stack on Ubuntu 20.04. The following articles were useful in that regard: Disable HWE and continue with GA kernal of 16.04? https://wiki.ubuntu.com/Kernel/LTSEnablementStack

$ sudo apt install linux-generic
$ sudo apt remove linux-image-5.8.0-34-generic linux-headers-5.8.0-34-generic linux-modules-5.8.0-34-generic linux-modules-extra-5.8.0-34-generic linux-hwe-5.8-headers-5.8.0-34 linux-generic-hwe-20.04

After reboot the system is back on Linux 5.4.0-59-generic and "apt update" does not offer upgrade to Linux 5.8 any more.

Solution 2:

I just ran into the same problem with my notebook (Ryzen 4 + rtx2060). The cause was the custom GRUB flags "nomodeset amdgpu.dc=0" I was using.

I restored the /etc/default/grub to its default, ran sudo update-grub and everything is running again.

Plus kernel 5.8 and nvidia drivers 460 fixed almost every issue I had (black screen after suspend, hdmi not working, many games not running).

Hope it helps