Cannot use my dual-monitor setup via docking station anymore

[Jeroen Ruigrok van der Werven]

After the 13th of April I cannot use my dual-monitor setup anymore. These are driven via DVI from my Dell docking station from my Dell Latitude E6530. When I click 'Use this display' for any of the externally connected monitors it tries to do something but in the end they get disabled and only the laptop monitor remains with checkmark.

When I hook up a HDMI directly and configure one of the monitors via xfce4-display-settings, shutdown, and then boot via the docking station I get video on the via DVI connected monitor that was previously configured. Trying to then use both monitors will shutdown the external monitor and only show the laptop screen.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xfce4-settings 4.12.0-2ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6
Uname: Linux 4.4.0-18-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
CurrentDesktop: XFCE
Date: Mon Apr 18 10:04:22 2016
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/xfce4-display-settings
InstallationDate: Installed on 2015-12-21 (118 days ago)
InstallationMedia: Xubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
SourcePackage: xfce4-settings
UpgradeStatus: Upgraded to xenial on 2016-03-17 (31 days ago)

[Jeroen Ruigrok van der Werven (asmodai)]

Attached the xorg.conf, which basically is set up to let X do most of its detection. And it does detect all the necessary monitors without problems.

[Jeroen Ruigrok van der Werven (asmodai)]

The attached X log shows how there's a bunch of connects and disconnects going on when trying to use the monitors via the 'Use this display' checkmark.

[Jeroen Ruigrok van der Werven (asmodai)]

So, playing around with xrandr, I can get my dual monitor working in mirror mode with the following (with DP-0 already enabled due to the previous direct hookup via HDMI):

% xrandr --output LVDS-0 --off
% xrandr --output DP-1 --left-of DP-0
% xrandr --output DP-1 --mode 1920x1080

% xrandr
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384
VGA-0 disconnected (normal left inverted right x axis y axis)
LVDS-0 connected (normal left inverted right x axis y axis)
   1920x1080 60.15 + 40.06
DP-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 531mm x 299mm
   1920x1080 60.00*+
   1680x1050 59.95
   1600x1200 60.00
   1440x900 59.89
   1280x1024 60.02
   1280x960 60.00
   1152x720 60.00
   1024x768 60.00
   800x600 60.32 56.25
   640x480 59.94
DP-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 509mm x 286mm
   1920x1080 60.00*+
   1680x1050 59.95
   1440x900 74.98 59.89
   1280x1024 75.02 60.02
   1280x960 60.00
   1152x864 75.00
   1024x768 75.03 70.07 60.00
   800x600 75.00 60.32 56.25
   640x480 75.00 59.94
HDMI-0 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 disconnected (normal left inverted right x axis y axis)

Which leads me to think the problem definitely lies not with X in any way, but with how xfce4-display-settings and it trying to drive something else, libXrandr maybe?

[Sean Davis (bluesabre)]

Are you still experiencing this issue with a currently supported release (focal, impish, or jammy)?

[Jeroen Ruigrok van der Werven (asmodai)]

It's been six years. I do not have access to that hardware setup anymore, sorry.

[Sean Davis (bluesabre)]

Thanks for the follow-up. Closing this one out.