Comment 23 for bug 1313539

I experienced this problem when I switched from DVI to Display-port due to purchase of a a new monitor "LG 34UC97" running a resolution of 3440x1440.
- (K)Ubuntu version is 15.10
- drivers installed are "plain" out of the box, more or less beside the usual "apt-get upgrade".
- GPU is definetly a "nvidia geforce gtx 750 TI", however ubuntu reports it as a "GTX 970". My previous ubuntu (?) reported the card correctly.
- nvidia drivers are the one installed via kubuntu, namely 352.63. I tried to "handinstall" the latest from nvidia but that screwed up so I rolled back.

1) The problem occurs in the following cases:
a) user must be logged in. screen-log or not, does not matter.
b) display-port attached monitor is switched off (e.g. over night).
c) monitor is switched on but complains now about not receiving a display.

2) The problem does NOT occur when:
a) no user is logged in, e.g. only kdm/lightdm login screen is there.
b) on windows 10 ( I have installed parallel)

I assume the GPU switches off its "service" via display-port to the monitor once the monitor is switched off.
However it does not resume "service" when the monitor comes back again.

The problem cannot be so difficult to solve as it does not happen in 2b) and especially in 2a) mentioned before.

Are there any consolidated updates and solutions for the topic?

thanks.