kubuntu 20.04: kernel hwe 5.15.0 hangs at Loading initial ramdisk

[Paulo da Silva]

I have installed a hwe kernel in my kubuntu 20.04.
 I needed to do that because using the standard kernel caused random freezes.
It has been working pretty well for long time even after changing a couple of kernel versions, the last working one being 5.13.0.

Now there came another version 5.15.0 after a normal update. After reboot the system hangs at "Loading initial ramdisk"!

Booting 5.13.0 still works fine.

I have tried to rebuild initramfs, reinstall the nvidia drivers, update-grub. No success

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Libera.chat.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1981518/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1981518

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Paulo da Silva (psdasilva)]

I could not to do apport-collect 1981518.

I saw a turn around in
https://unix.stackexchange.com/questions/671087/ubuntu-21-04-hangs-at-loading-initial-ramdisk-after-kernel-update-with-luks
that worked. Now I have a normal boot.

Change in /etc/initramfs-tools/initramfs.conf
MODULES=dep
update-initramfs -c -k 5.15.0-41-generic
update-grub
reboot