KDE Crashes with 430.26

Greetings!

I’ve also attached an nvidia-bug-report.log.gz for your amusement.

Laptop is Dell Precision 7530 with GP104GLM [Quadro P3200 Mobile] - Core i7-8750H with 32GB RAM
NVIDIA Driver: 430.26 from graphics PPA
Kernel: 5.0.10
Distro: Linux Mint 19.1 (Ubuntu 18.04)
KDE Release:
plasmashell --version
qt5ct: using qt5ct plugin
plasmashell 5.12.7

  kf5-config --version
    Qt: 5.9.5
    KDE Frameworks: 5.44.0
    kf5-config: 1.0

When using any of the file managers (Dolphin, Nemo, Thunnar) and I try to delete an unrelated file or occasionally with a PDF display command if I double click a PDF in the file manager, KDE crashes, I hear a beep and I get to a black screen. I can F2 and get to a console window and log in normally. The xorg still appears to be running and if I was playing music via Pandora, that keeps playing. I can then issue a sudo service sddm restart and the screen comes back, but everything I was working on is gone. :-(

When I look in the dmesg output, I see a lot of these:
[ 86.721823] iwlwifi 0000:70:00.0: Unhandled alg: 0x707
[ 91.240789] [drm:nv_drm_gem_fence_attach_ioctl [nvidia_drm]] ERROR [nvidia-drm] [GPU ID 0x00000100] Failed to lookup gem object for fence attach: 0x00000004
[ 91.240799] [drm:nv_drm_gem_fence_attach_ioctl [nvidia_drm]] ERROR [nvidia-drm] [GPU ID 0x00000100] Failed to lookup gem object for fence attach: 0x00000009
[ 91.240802] [drm:nv_drm_gem_fence_attach_ioctl [nvidia_drm]] ERROR [nvidia-drm] [GPU ID 0x00000100] Failed to lookup gem object for fence attach: 0x0000000a
[ 91.240805] [drm:nv_drm_gem_fence_attach_ioctl [nvidia_drm]] ERROR [nvidia-drm] [GPU ID 0x00000100] Failed to lookup gem object for fence attach: 0x0000000b
[ 91.240807] [drm:nv_drm_gem_fence_attach_ioctl [nvidia_drm]] ERROR [nvidia-drm] [GPU ID 0x00000100] Failed to lookup gem object for fence attach: 0x0000000c
[ 91.240809] [drm:nv_drm_gem_fence_attach_ioctl [nvidia_drm]] ERROR [nvidia-drm] [GPU ID 0x00000100] Failed to lookup gem object for fence attach: 0x00000013
[ 91.240811] [drm:nv_drm_gem_fence_attach_ioctl [nvidia_drm]] ERROR [nvidia-drm] [GPU ID 0x00000100] Failed to lookup gem object for fence attach: 0x00000011
[ 91.240813] [drm:nv_drm_gem_fence_attach_ioctl [nvidia_drm]] ERROR [nvidia-drm] [GPU ID 0x00000100] Failed to lookup gem object for fence attach: 0x00000016

I’ve found other references to this error, but no concrete solutions. Can anyone suggest a fix?

Regards,

Mike
nvidia-bug-report.log.gz (1.1 MB)

A little more info… It appears that its’ got something to do with dual displayport monitors hooked through a Dell docking station. If I do the same thing with Xreader V 2.0.2 without the docking station, it seems to work. Now, I’m going to try a mix of DP and HDMI to see if that fixes it.

OK, confirmed that it’s an issue with the Dell Thunderbolt dock. It works fine in Windows, as you would expect. But, if I plug both external monitors into the HDMI and mini-DP jacks on the laptop directly, then the system works as it should and doesn’t die when I use Xreader or doing things with one of the file managers. Of course, I’ve also seen problems using a Thunderbolt dongle and the HDMI port. It just doesn’t seem to work. Sigh… So, I’ve certainly got a work around, but it kind of defeats the purpose of the docking station to have to plug all of these cables in.

Please run
grep modeset /etc/modprobe.d/* /lib/modprobe.d/*
to find the file containing

options nvidia-drm modeset=1

change the 1 to 0, then run
sudo update-initramfs -u
and reboot. Then check if the dock works.

Yes, that worked! That’s quite the obscure little option and it was squirreled away in /lib/modprobe.d where I never would have thought to look for it. Just by the name, I’d guess that this disables some sort of video mode setting option for the DRM module. Is there documentation someplace that describes what this option is supposed to do?

I don’t think there’s any in-depth docs about it. In a nutshell, setting it to 1 enables Linux kms conformant drm modesetting, enabling udev events and drm sysfs nodes but also prime sync, i.e. vsync on hybrid graphics. The kernel messages about the drm fence points into that direction. Looks like the driver somehow got confused by the dock into thinking you had hybrid graphics but you don’t. So turning it off is a workaround.