display port monitor not useable after standby/poweroff and power on again

Hi.

Have this problem on two computers, one with openSuSE (previously 13.1, now tumbleweed) having a GTX970, the other running Mageia 5 having a GTX980Ti.
Connected Display is a Samsung U28D590, running with 3840x2160@60Hz connected via DisplayPort. Same display for both machines (no switch or anything in between, direct connection).
System runs normally fine, but when I turn off the display for a while and then turn it on again, the screen remains black. (Has to be off a bit longer, like a minute or more, not reproducible with only a few seconds off-time). The only way I’ve found so far to reactivate the display is to restart the X-Server so the gpu gets re-initialized. This only happens with high resolution modes. The standard text-console (tty) remains usable.
Driver used is latest version: 361.28. But also happened with all others before that support the GTX900 series.
Having to keep the display powered up fully all the time while letting the computer run a lengthy job that requires the X-Server is not a good workaround.
This was no problem before when I still had a GTX580 with a display connected via DVI. So the X-Server shouldn’t be the problem.

I have the same issue on a GTX 950 on 4k@60hz. There seems to be some sort of bug in the driver. I ended up writing a script to fix this for my mythtv box till this gets resolved. I think it might have something to do with the HDCP but there’s no confirmation either way.

Similar thread here with no resolution

https://devtalk.nvidia.com/default/topic/901948/linux/gtx-970-355-11-on-fc22-refuses-to-recognize-tv-used-as-monitor-upon-display-sleep-resume-tv-resta/

Here’s my thread at ubuntu forums

http://ubuntuforums.org/showthread.php?t=2305154&page=2

one guy said it was xfce-settings needing to be downgraded but no confirmation of that either since most people that are posting here at nvidia forums aren’t mentioning what distro / window manager they are using.

anyone have more details?

Hi,
thanks for the links.
But I don’t think xfce-settings is the main issue as on the openSuSE machine I’m using KDE. With the Mageia-PC it actually is XFCE, but have to look where to find older packages as the repositories only offer 4.12… will see if I find something…
But it can’t be a long-term solution to have to stick to old packages (if it works). Should be fixed at the root of the problem. Because the problem also exists - if somewhat different - on ms windows, but there it’s like the desktop is coming up again but is “re-sorted” as if it temporarily had a resolution of 640x480. So it is something that is at the very core of the driver or somewhere hardware bug (which should also be fixable through drivers).
Regarding the script: as I’m using a normal desktop PC, how do I bind it efficiently? In my case I don’t have a specific power on signal from a remote and don’t want it to run constantly or having to switch to a terminal and login there to run the script to reactivate the display. I mean, is there any signal / event that notifies about the display being switched on again (that nvidia fails to react upon but at least passes through)?

There’s a QT bug that causes this in KDE: https://bugreports.qt.io/browse/QTBUG-42985 .

https://devtalk.nvidia.com/default/topic/522835/linux/if-you-have-a-problem-please-read-this-first/