Displayport woes on Quadro K620/P620

Sorry if this is a bonehead question, but I haven’t been able to successfully search for an answer, which means either:
a) I’m not searching correctly
b) This is such a weird problem that nobody else has this (probably because I made a bonehead error)

HW Setup:

Problems showed up when we switched to new monitors that use DisplayPort by default. Hardware setup that exhibits problems:

Dell Precision Workstation T5820
32GB RAM
Quadro P620 Card
Nvidia Driver (418.43)
RHEL 6.10 (2.6.32-754.11.1.el6.x86_64)

It also shows up on:

Dell Precision Workstation T5810
32GB RAM
Quadro K620 Card
Nvidia Driver (410.93)
RHEL 6.10 (2.6.32-754.11.1.el6.x86_64)

Symptoms:

A) If the display cable becomes disconnected, the output shuts off and even after plugging it in, I have found no way to get the display output re-enabled short of a reboot – this is highly annoying

B) If the monitor is powered off, the windows disappear. Turning the monitor back on gets a blank desktop and the state of the windows is lost – at least a reboot is not required – a restart of the X server or the window manager is required (still annoying)

C) I can’t get nvidia-settings to work (claims ERROR: Unable to load info from any available system)

I can avoid (B) by using a DP to HDMI converter and using the HDMI interface on the monitor. This points to the silly DP PnP behavior.

Any help or suggestions is welcome.

nvidia-bug-report.log.gz (1.15 MB)

Please run nvidia-bug-report.sh as root and attach the resulting .gz file to your post. Hovering the mouse over an existing post of yours will reveal a paperclip icon.
https://devtalk.nvidia.com/default/topic/1043347/announcements/attaching-files-to-forum-topics-posts/

Log attached.

Please check if adding

Option "AllowEmptyInitialConfiguration" "true"

to the Device Section of your xorg.conf changes the behaviour at least partially.

Adding

Option “AllowEmptyInitialConfiguration” “true”

to the Device section of the xorg.conf changed things…

  1. Unplugging the DP cable and plugging it back in does not result in an output that is disabled requiring reboot. This is a step in the right direction.

  2. However, the restored screen has lost its windows and window manager. It requires a X server restart (not a reboot).

  3. Turning the monitor off still results in loss of most windows with the exception of Firefox. However, the window manager (KDE) seems to have gone haywire and this again requires a X server restart.

It seems that the PnP behavior of DP is an unwanted complication…

The main reason is that kwin is not designed to run headless, please check if disabling the kscreen2 service improves anything.