Logitech webcam borked...AGAIN

Okay so…to outline

I had 16.04.1 installed. Everything working okay

For reasons too long to go into, I reinstalled 16.04. But, this time, again for reasons too long to go into, I downloaded the latest version number - which is 16.04.2. However, after installing that I found that a number of things weren’t working any more. On the software front, this included Qbittorrent, my preferred torrent client. On the hardware front, my Logitech web-cam was no longer being picked up.

So, I reinstalled a UM 16.04.1 and, lo and behold, Qbittorrent worked again, as did my web-cam. However, I am now a week in and, after several updates and “upgrades”, the web-cam has stopped working again! For the moment, Qbittorrent is still working. but we shall see if that continues.

What the hell is going on with Ubuntu (I am trusting this is not a UM specific issue)? Things as fundamental as web-cams should not be borking up like this. It makes using Ubuntu as a daily driver on which basic things like this should be relied upon, more or less impossible.

As an additional note, I have found if I issue the command


it will bring the web-cam (seemingly randomly) to life around 50% of the time. So, this suggests it is a USB issue (my web-cam is a usb device) as opposed to specifically a web-cam issue. Also, when i issue the lsusb command, half the time the terminal then just hangs and it takes half a minute or more to list the devices. Sometime it continues to hang and I have to kill the terminal and try again.

This is just not good enough. We had all of this with samba earlier in the year with the gvfsd bug. Why push “upgrades” down the line to the end-users if they are going to break parts of the system?

I’d be grateful if anyone has got any advice as to how I can fix this or, at least, some kind of script/command bodge that will force the web-cam (or force the usb port) to be picked up.

1 Like

If I could help you I would. My best advice would be to try a different distro if you experience too many problems with UM 16.04.

I use Linux because I like open source and I like to tinker a little bit. If I had to rely on only one computer I might have opted for a Mac. Many Linux developers seem to agree.

Desktop Linux isn’t “pro”, it’s “enthusiast”. That’s how I see it. I do use Linux for work-related things, but mostly it’s an interesting toy. So a lot has to do with expectations. Maybe you expect a workstation. I don’t think desktop Linux is at that level.

As I said I would have helped you if I could, but I have no idea. Webcams shouldn’t stop functioning, but this is the current level of quality you get with Ubuntu. I might say Ubuntu 14.04 was a better release, but that doesn’t help you.

Maybe someone with more technical knowledge can help you troubleshoot.

1 Like

A thought:

If the webcam is connected to a USB-hub this could interfere.

1 Like

No, it is plugged directly into the port on the back of the pc, where it has always been since I built the PC around a year and a half ago.

I am now pretty convinced this is a USB issue, as opposed to a specifically webcam issue. It is a USB 3 port, so I am going to plug the webcam into a usb 2 port tonight and see if it makes any difference

One thing is for sure, my hardware has not changed. So, the only thing that must have changed to casue this failure, whatever it is, is the software system. Which then begs the question of where in the hierarchy the problem lies

Ubuntu Mate -> Ubuntu -> Debian -> Linux

1 Like

USB 2 is more reliable in my experience.

Ubuntu Mate -> Ubuntu -> Debian -> Systemd -> Linux :wink:


I’m seeing a lot of random banter, mostly ado about nothing really. Ultimately, it boils down to actually approaching the issue from a methodical/analytical point of view. And not making gross assumptions about how fit or unfit Linux in general is.

Case in point – It actually stopped working properly where it used to work properly before… on Ubuntu, using the Linux kernel. So, nothing wrong on that front, generally speaking. Only specifically speaking. As in, a specific version of a specific distribution.

So, let us approach this methodically – what is different now as opposed to your fresh install (which does not suffer from this issue)? Webcam-wise, it is going to be relatively simple to analyze. Because there is a likely culprit – the kernel version. As far as your torrent client is concerned, that one is slightly more complicated but even still, the client no longer working at all suggests a dependency issue more than anything.

As for your first issue, the webcam… drop into a terminal and…

sudo su
nano /etc/default/grub

In there you will find the following lines (not necessarily exactly the same as my example):


However, you will want to make them look exactly like that. And then a few keystrokes to save the file and quit nano.

CTRL+O -- Save
Enter -- Overwrite the file
CTRL+X -- Quit nano

And then…


And reboot. It should drop straight into grub. We’re going to be launching a different kernel version. So…

Advanced Options for Ubuntu

And load the oldest kernel version, most likely the one that was installed with the fresh install. Do not run the recovery mode, just load normally. Is the webcam behaving as expected now? If so, found the culprit.

As for the torrent client – Are other torrent clients still functioning normally? Not going to suggest you switch clients, just to confirm it’s nothing more dire than the specific client for some reason no longer functioning.
Try Deluge (sudo apt-get install --install-recommends deluge). I know that one to work just fine even with 17.04 and completely updated.

Which part of the following is “random”?

Ubuntu 16.04.1 LTS, until about two and a half weeks ago, was my OS and had been for some time. At that point, there was no problem with either the USB web-cam or Qbittorrent.

About two and a half weeks ago, for other reasons, I rewrote my machine by downloading and installing the latest UM which was 16.04.2 LTS. Following the installation, the webcam started acting up in the way I have described and also Qbittorent stopped working.

I then rewrote the machine again with a copy of UM 16.04.1 LTS (which I downloaded as a fresh copy of the main Ubuntu site) and the web-cam issues disappeared and Qbittorrent was working again. This was about a week ago.

However, the other day, following updates and upgrades, the web-cam has stopped working again (or is working extremely intermittently). Qbittorrent is, for the moment, still working.

Apart from changing UM version from 16.04.1 to 16.04.2 and then back again to 16.04.1 (fresh copy) and apart from the upgrades that I have recently applied, nothing else has changed on my system in either software or hardware terms.

I should also state that this is not a novel issue either. I have personally experienced this before where a new version number comes out that borks one thing or another (in my case, previously, a Canon LBP Laser printer in Ubuntu 12.04 LTS). Only to find that it is then passed down the line to previous versions in subsequent updates and so causes the same problem there where it did not exist before.

The problem may well be located where you have suggested. and I am grateful for your assistance. However, that still does not excuse this kind sudden borking of hardware/software on users’ systems as a consequence of updates.

[quote="stevecook172001, post:8, topic:13690"]However, that still does not excuse this kind sudden borking of hardware/software on users' systems as a consequence of updates.[/quote]It sounds to me like you've already made up your mind. Now, I'm not one to judge overly harshly unlike other people I've come to know but really, maybe you should consider the following --

No piece of software in the entire history of software has ever been completely free of bugs.

None of it.

And, quoting you, yourself:

[quote="stevecook172001, post:8, topic:13690"]However, the other day, following updates and upgrades[/quote]How about, as opposed to just repeating original complaints you work with me here in finding out which update caused the issue. So as to address the issue. Instead of just... complaining about it. And maybe, and this is a novel idea, never had to do this on Windows (sarcasm!) -- avoiding that particular update until it is fixed.

Can't begin to tell you how often I had to avoid a particular update on Windows to prevent the system from completely breaking. Oh, and let's not forget the "free" "upgrade" to Windows 10 that broke more systems than I'd care to count, globally.

As stated, no piece of software has ever been completely free of bugs. It's impossible. Want to know why... here's a picture:

We made the software. We're flawed beings. Hence the software being flawed.

Sorry about this tone but I'm just not overly fond of people complaining repeatedly when there are others (like myself) that genuinely are trying to help them to either identify the issue or possibly even resolve the issue. Nothing personal, 20 years of customer service work finally taking its toll.

I repeated the original complaint because you apparently found it too “random” to, presumably, understand.

Are you now saying that wasn’t the case. In which case, why refer to it as “random”?

And please don’t use the “trying to help” line to excuse your supercilious tone. I am one of those who offer help to others on a regular basis both here and elsewhere and so am well aware of what constitutes time wasters. I am not one of them and I resent the implication.

[quote="stevecook172001, post:10, topic:13690"]I repeated the original complaint because you apparently found it too "random" to, presumably, understand.[/quote]And how did you arrive at the conclusion the randomness was referring to the problem you were having? Because, it was not. It was the additional fluff. The needless banter.

And in part not even your own.

I quote:

My best advice would be to try a different distro if you experience too many problems with UM 16.04.

How is that helping anyone? That's neither solving the issue nor actually helping. Because, well, I'm guaranteeing you, it's a kernel version issue. And so, you would just continue to experience the issue. Because, well, same updated kernel!

[quote="stevecook172001, post:10, topic:13690"]I am not one of them and I resent the implication.[/quote]I did not imply you were a time waster and I resent the inference, to be quite honest with you. I was merely implying you were exaggerating the issue. And, again, in part not even you were. I was merely advocating addressing the issue as opposed to highlighting the issue.

Had I truly believed you were a time waster, why would I have been here wasting my time? You're not a time waster. You're someone with a genuine issue that needs genuine addressing and I never implied otherwise. Perception is only half the truth, at best.

It could be an architectural problem (kernel updates) or it could be housekeeping (systemD monitoring your system and its devices). And housekeeping probably stems from a new or revised kernel. Unfortunately, I don’t immediately know enough to point you in a helpful direction at this time. But as I look into a slightly different 16.04 problem, I’ll keep an eye out if that is any consolation. Things keep changing on us…


Okay… update

I have just installed, as is my usual practice with a new system installation, the Ubuntu studio metapackage. This includes, amongst other things, the low latency kernel.

Hey presto, the USB webcam is working again.

[quote=“stevecook172001, post:13, topic:13690”]Hey presto, the USB webcam is working again.[/quote]Hey, presto… the exact culprit I predicted – the kernel.

Anyhow, this is good, solid information. Now you have something to file a bug report against.


What kind of benefit does the low latency kernel provide?

[quote=“mdooley, post:15, topic:13690, full:true”]What kind of benefit does the low latency kernel provide?[/quote]Exactly what its name implies – low latency.

For a rough idea:

Thanks. I went looking for myself and found several descriptions of what and why low latency is used in ubuntu and linux in general. This page seems to be clearer than several others - https://askubuntu.com/questions/614235/side-effect-on-upgrading-kernel-from-generic-to-low-latency
Thanks again 1Q7FE6zp.

[quote=“mdooley, post:17, topic:13690”]Thanks again 1Q7FE6zp[/quote]You’re welcome. As another aid, I can tell how what it’s doing for me personally. I’m running a custom kernel, the ck kernel. Which is purely optimized for low latency and includes things like the BFQ IO scheduler.

Why I’m running it is because the generic kernel runs single tasks incredibly well but quickly loses out its edge when faced with running multiple things at once. And in this day and age, who actually runs just single tasks? Even within individual programs, there are usually dozens of tasks running at the same time (threads). I wanted a very responsive, very comfortable experience that even if the hard performance isn’t as optimized as the generic kernel’s performance is, I actually never have to wait long for anything. Because no matter how many things I’m doing simultaneously, the low latency configuration is making sure every task, every application is getting enough CPU time to do what it needs to do.

I use the low latency kernel as a necessary underpinning of the Ubuntu Studio meta-package which I usually install on top of UM

My main concern now is if these “updates” that stopped my usb web-cam working now migrate across to the low latency kernel. They have done so in the past. So we shall see.

I should say, this issues of problems being introduced into a new version of Ubuntu, be it either via the desktop or via the underlying Ubuntu base or via the Linux kernel (or Ubuntu modified kernel) and then being pushed back/sideways into previous/sister ones via “updates” is something I have experienced on a number of previous occasions with a number of applications/devices including:

Canon LBP 2900i laser printer - Ubuntu 12.04

PNP LTSP - Ubuntu 14.04

And the current issues I have experienced with Ubuntu 16.04

Just done an apt-get update and apt-get upgrade

Web-cam borked again

If I issues the command:


After hanging for 30 seconds or more, it eventually provides a list which includes the web-cam. At which point, if I open Cheese it will then work.

However, as before, half the time I issues the lsusb command, it just hangs and never provides the list of usb devices (or, at least, not after waiting a minute or two and so necessitating me killing the terminal)

[quote=“stevecook172001, post:20, topic:13690”]Web-cam borked again[/quote]Might I suggest simply not updating for the time being until we’ve identifier the exact update that is causing the issue?

Regardless, did you happen to pay close attention to the update process? A log might help us identify the exact update that is causing this issue. To help resolve it by filing a bug report against whichever package is causing this problem.


Note: /var/log/dpkg.log contains a log of all actions concerning packages (updates, removals, installations and so forth and so on).