Kubuntu installed successfully on Dell laptop, but hangs after 'apt autoremove'

[RichardR]

Hello,
I recently installed Kubuntu 20.04 on a Dell XPS L502X laptop with 8 GB RAM and a 250 GB SSD drive, and everything worked just fine for several weeks, including several updates.
However, after performing apt autoremove things went south: when starting the machine, instead of the usual login screen, the following lines appeared:

[ 7.705327] cdc_wdm 2-1.6:1.8: wdm_int_callback - 0 bytes
[ 7.706244] cdc_wdm 2-1.6:1.5: wdm_int_callback - 0 bytes

Every two seconds, the screen goes blank for a moment, and then these lines return. From that point on, I can't do anything any more - not even logging into a shell with Ctrl+Alt+F2 etc (password error, probably because of the 2-second loop).

As I could not easily fix this, and this was a spare laptop anyway, I decided to reinstall Kubuntu to see what would happen. And indeed I see that updates are no problem, but once again apt autoremove causes the machine to hang in an endless 2-second loop on the next boot, with the exact same two lines on screen (apart from a slightly different timestamp, that is).

Starting in recovery mode by pressing Esc on boot shows nothing unusual. There are no further updates, and there is plenty of disk space available.

Does anyone have any idea what may cause this? And of course how to fix this? Could it be that autoremove messed up, and removed something that was actually needed?

Thanks already, best regards,

Richard

[Snowhog]

Welcome to KFN.

Why would you be running apt autoremove on a fresh installation? After a brand new installation, the 'usual' daily maintenance commands from the konsole would be:

sudo apt update
sudo apt full-upgrade
sudo apt-get clean && sudo apt-get autoclean

If you are using Discover; don't. Really. Don't. You will be better served doing all your system maintenance from the CLI (Konsole).

And, right after a new installation, make sure you have rebooted.

[RichardR]

Hello,

Why would you be running apt autoremove on a fresh installation?

Force of habit - in the distant past, I've had some disk space issues due to lots of stuff that was no longer necessary.
And indeed I already do updates etc. from the command line. When apt throws a message that a number of packages are no longer needed (this is after a couple of weeks with several updates), I use apt autoremove. Up until today, this never caused problems.

Anyway, I'll just wait a while to see if someone can suggest an easy fix to get the thing up and running again. If not, I guess I'll have to reinstall.

Thanks for your comments, best regards,

[claydoh]

And indeed I see that updates are no problem, but once again apt autoremove causes the machine to hang in an endless 2-second loop on the next boot, with the exact same two lines on screen (apart from a slightly different timestamp, that is).

So, what you might want to do, is :
first make sure you have fully updated after the fresh install -- either via sudo apt update and sudo apt full-upgrade, or via Discover (both are doing the exact same thing)
Then, run sudo apt autoremove, if you want -- this is in no way mandatory for each update, but is useful if you are concerned about drive space and/or keeping things tidy/clean.
But before you click {y} to continue. look at what is being offered for removal -- if unsure, copy it it and post it here for advice.

[RichardR]

OK, just reinstalled -> full update -> shutdown -> restart, no problem.

And a closer look at what exactly autoremove would remove seems to give some clues:

The following packages were automatically installed and are no longer required:
libdpkg-perl libfile-fcntllock-perl libfwupdplugin1 libnvidia-cfg1-390 libnvidia-common-390 libnvidia-decode-390 libnvidia-encode-390
libnvidia-fbc1-390 libnvidia-gl-390 libnvidia-ifr1-390 libx11-xcb1:i386 libxnvctrl0 nvidia-compute-utils-390 nvidia-kernel-source-390
nvidia-prime nvidia-settings nvidia-utils-390 pkg-config screen-resolution-extra xserver-xorg-video-nvidia-390
Use 'sudo apt autoremove' to remove them.

Most of it is nvidia driver stuff, and apparently, it is still needed to start the window manager.

This is what the proprietary driver window has to say about it:

Apparently, the nvidia 390 driver is installed, but not in use - and from what I see, I can't enable it.
I'm not certain what this 'manually installed driver' is (nouveau?)

Any thoughts on this are appreciated.

Best regards,

[dejjanku]

Very good question. I had the same issue: after fresh installation, Kubuntu 20.04 installs driver for nvidia and marks it as manually installed (as indicated in the screenshot above). Consequently, auto remove attempts to remove it but in my case it was working fine (prior to autoremove). Could you run NVIDIA-SMI?

I think 390 is rather old and even more not compatible if kernel is newer version. Try installing nvidia 510 driver prior to removing these. Of course, it has to first appear and then to be selected in this list. This version (510) impacts differently on different kernel versions: sometimes it crashes it, sometimes it could not be installed. Its even more interesting that I did not have the same issue on Ubununtu 20.04 which out of the box offers to install newer driver versions.
Otherwise, try nvidia forum or Ubuntu forum for more resources. You will see helpful nvidia employees fileing bugs based on forum posts...
www linuxcapable com/install-nvidia-510-47-xx-drivers-on-ubuntu-20-04-lts/
forums developer nvidia com/t/cant-boot-after-upgrading-to-510-driver-on-ubuntu-20-04/202625/15

[GreyGeek]

The 390 Nvidia driver is rather old, but so is the GT 525M Nvidia chip. That's why the 390 is listed by Nvidia as the preferred driver.
https://www.nvidia.com/Download/driv...x/184603/en-us
"GeForce 500M Series (Notebooks):
GeForce GTX 580M, GeForce GTX 570M, GeForce GTX 560M, GeForce GT 555M, GeForce GT 550M, GeForce GT 540M, GeForce GT 525M, GeForce GT 520M, GeForce GT 520MX"

Checking with the Nvidia 510 driver for Linux we do not see the GT 525M listed among the supported devices
https://www.nvidia.com/Download/driv...x/184911/en-us


The OP should purge the 390 driver from the system, including config files which may have to be removed manually from the home account, then reinstall the driver using Muon, accepting all recommendations. Or, run "ubuntu-drivers devices"

[RichardR]

The OP should purge the 390 driver from the system,

Doesn't this amount to the same thing as what autoremove proposes? I'm pretty sure that purging the present 390 driver from the machine renders it inoperable again, so I must be really sure that what I install after purging works properly, and that is a bit of a problem (see further down).

including config files which may have to be removed manually from the home account,

OK, I renamed ~/.nvidia-settings-rc to*.bak

then reinstall the driver using Muon, accepting all recommendations.

Well, there's a bit of a thing: when I search for all available nividia-390 packages, I get many hundreds of hits, for different kernels, different hardware and whatnot. I have no idea what constitutes 'the' driver for my system.
So to be on the safe side, I marked all nividia 390 packages that were already installed for reinstall - but that didn't make any difference. (There were also no new recommendations for packages to install.)

Or, run "ubuntu-drivers devices"

This produces the following output:

WARNING:root:_pkg_get_support nvidia-driver-390: package has invalid Support Legacyheader, cannot determine support level
== /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0 ==
modalias : pci:v000010DEd00000DF5sv00001028sd000004B6bc03sc00 i00
vendor : NVIDIA Corporation
model : GF108M [GeForce GT 525M]
manual_install: True
driver : nvidia-driver-390 - distro non-free recommended
driver : nvidia-340 - distro non-free
driver : xserver-xorg-video-nouveau - distro free builtin

I don't know what to make of this.

Anyway, all your help and comments are very much appreciated! I haven't had to deal with problematic nvidia drivers for many years, and this reminds me of the (not-so-)good old days, when you really had to get hands-on to get graphics cards working.

Best regards