At work, we are trying to solve a display issue where we can’t get any X screens to consistently stay up when we switch to and from a monitor. I’ll try to draw it out below…
|Machine A| |Machine B|
\ _________ /
|Monitor 2| |Monitor 1|
What we try to do is reboot Machine A and have X server start while the KVM is pointed at Machine B. I think of it as a pseudo-Headless boot. I believe that I am using the ConnectedMonitor and UseDisplayDevice options correctly to force the displays through the KVM. I am also using the EDID information that nvidia-settings created for me.
Now, the problem… If we are pointed at or away Machine A when we boot, there is no problem and we get the exact server layout that we want (Perfect!). Unfortunately, if we flip from Machine A to Machine B then back to Machine A, we lose one of our displays (Monitor 2). Checking out the log file, it seems that the switch from A -> B and B -> A are recognized and the display information is reloaded but the monitor is not awake.
To me, it seems like an issue with the KVM “Hotplugging” the Displays. I would love to disable the Hotplugging Events, but the documentation says you can’t do that for DP :)
The work around for now is using xrandr commands to turn the monitors off then back on, but that isn’t a solution we would like to use.
Please let me know if I can provide any other info. I can’t seem to find the attach button on the thread creation page so I’ll try to add my logs in a separate reply.
OS: RHEL 7.3
Driver: Nvidia 375.66 downloaded from Nvidia site
Monitors: Dell UP3017 (DisplayPort)
Graphics Card: Nvidia NVS 310
nvidia-bug-report.log.gz (85.7 KB)
Xorg.0.log (30.2 KB)
xorg.conf.txt (3.28 KB)