KUbuntu 18.04.1LTS w/ Quadro K1100M running Nvidia 396.54 flickers after unsuspend (Take 2)

In some ways, this is a continuation of a previous topic I opened: https://devtalk.nvidia.com/default/topic/1038760/linux/kubuntu-18-04-1lts-running-nvidia-390-77-flickers-and-trashes-graphics-buffers-after-unsuspend/post/5277719/#5277719

I’m creating this new topic to remove noise about 390.77 and because my other topic is now being ignored. I’m also ignoring the trashed buffers, which still happens with perfect regularity, but I can live with.

This morning, after unsuspending, I have a new kind of flickering. Not as bad as the old (see previous topic) which I’ve also seen on 396.54, but bad enough to make me reboot my box.

This flicker is not most of the screen flicker while a dialog is open, but instead just window manager features, such as title bars and borders, are flickering. See the attached video.

Any ideas on how to fix this problem? Besides rebooting or restarting X?
nvidia-bug-report.log.gz (151 KB)
20180913_112258.mp4.gz (15.4 MB)

There are many known issues that affect the combo KWin+Nvidia drivers, that’s one.
See if changing the render backend of KWin gets you better results.

Generix, do you represent Nvidia? Does Nvidia comment on or even monitor these forums any more? Is this even the right place to ask Nvidia for support? Do they seriously support their linux drivers or is it just a pass time now?

Your answer was a non-specific hand wave: “The problem is somewhere over there. Go fiddle with that and leave me alone, kid.” This is fitting with bad level one support and your last answer of get to the lastest drivers. After that didn’t resolve the problem, you just ignored that previous topic.

So, do you care to be more specific as to what is going on? Care to recommend a renderer for KWin that is suppose to work with Nvidia’s drivers? Or am I suppose to spend the next few months trying various “solutions” in hopes of hitting on some previously unknown magic? Is this an Nvidia bug or a KWin renderer bug? Can you point to a specific bug reference/tracker with details? Is this forum even the right place to report these bugs?

As you can tell, I’m frustrated with Nvidia and their handling of problems with their linux drivers. I’m not even doing anything exotic… just running a window manager so I can do my day job and now I’m wasting hours posting and trying things with no hope or reason to hope for success.

I’m interested in buying products that work, and I am willing to help debug things, but I’m not interested in fiddling with random knobs with little hope of success.

You’d think Nvidia could at least make software that works with a window manager, but that seems to be too much to ask these days.

Okay, I switched the Render Backend from Open GL 2 to XRender. That immediately trashed some of my wall paper related buffers.

If someone else reads this, the twiddle is located in Settings => Display and Monitor => Compositor.

Let’s just be honest. Confidence is low and likely hood of buying Nvidia again is also low.

And I switched back, because XRender wouldn’t render my task bar on the desktop correctly. When I switch to another desktop, I’d see the tasks from the previous desktop, but clicking on them resulted in behavior for the current desktop.

Now trying Open GL 3.1 renderer, but confidence is sinking fast…

Faster than I can type. Open GL 3.1 render results in the same bug as Open GL 2 that I reported at the top. Back to Open GL 2 renderer…

This should give you an impression of the numerous bugs that makes using the proprietary driver with kwin a gamble and subpar experience.
Driver or kwin bug? I don’t know, opinions differ depending on who you ask.
No fairy will come flying, wave its magic wand and lift the evil curse, sorry.
This is basically a user2user forum with devs reading and even fixing things in a triage manner, worst first.
I’m just a user trying to help, no kwin expert as I’m using mutter and have a hard enough time keeping that flying but presenting you the answers I have. Even if there are few and you don’t like them. As a byproduct, this even keeps your thread up at no extra cost.

Hello Generix,

Thank you for your reply. I appreciate you’re trying to help. You came across as an unmarked Nvidia employee. Nvidia used to post in these forums to help users… apparently those days are gone.

As to it being a driver vs. kwin bug, I spent some time reading tickets on the kwin site, and the conclusion more often than not is that it is a Nvidia driver bug, because it works correctly on Intel and AMD/ATI cards and drivers.

Looks like I’m stuck with lousy Nvidia drivers and no good choices. Well, next time I’ll try my luck with Intel or AMD.

Like said, Nvidia’s devs actually read this but don’t always answer, sometimes reported bugs are silently fixed. So if you don’t intend to throw your system out of the windows anytime soon, you should always upgrade to the latest driver and report the state in this thread.
Meanwhile, does restarting just kwin using
kwin --replace
after resume work around the issue?

“kwin --replace” does seem to be a useful work around. It removed the flickering without the pain of rebooting or losing my current windows. Thanks!

You could then put it in a script and bind it to Alt+F12 to have it a bit more comfortable.

I don’t have anything constructive to add here other than to say thank you for the posting the “kwin --replace” workaround! It is still relevant here in 2019.

The 430 driver introduced a new feature to fix that:
Fiddly to set up but works for me.

Too little too late for my most recent laptop purchase. Carefully selected a system without an NVidia graphics card.

One of my colleagues at work was not so fortunate. His shiny new laptop running KUbuntu came with an Nvidia graphics card crashes hard about once a week due to a driver bug (so it seems).

He’ll post separately in the forum in hopes for a solution.