I am running a new NVIDIA Quadro K420 graphics controller in a Red Hat Linux machine, coupled to a Club3D CSV-5400 MST Hub, currently driving two (2) Acer B276HUL monitors.
The CSV-5400 is new, Rev A1-2.1, FW 0.45.
Here are the relevant system details:
Linux atlas.as.utexas.edu 2.6.32-220.el6.x86_64 #1 SMP Wed Nov 9 08:03:13 EST 2011 x86_64 x86_64 x86_64 GNU/Linux
I am running the current NVIDIA driver, 361.42, and NV-Control, 1.29.
The two monitors are interfaced via DisplayPort 1.2 compatible cables, 2m long, and running in their default configuration at 2560 x 1440 x 60Hz.
From a cold boot, the system will run though POST as usual, boot, and start successfully executes, with the Gnome display as expected, and login prompt. Things behave, the monitors will go to sleep and reawaken on keyboard/mouse input, however logging out of the Gnome/X session causes both monitors to blank, and they will not see any signal from the DisplayPort/Club3D MTS hub. I can ssh into the machine, but any, and all attempts to restart the X session fail, and the monitors never leave their blanked state.
Only a cold reboot will restore operation.
I have done significant trouble-shooting, and find that removing the Club3D MST hub from the system in part remedies this problem, I can log in/out of the Gnome/X session without the single monitor blanking. Unfortunately, this is not a useful configuration, and in the longer term, we are planning on adding two more monitors…
I’ve tried various other things, including the ‘scan’ button on the CSV-5400, to no avail. Any interruption of the signal path on the DisplayPort connections (i.e. disconnecting/reconnecting a cable, power-cycling the hub via removal/insert of the supply connector, turning off/on one of the monitors) results in similar behavior.