I am running Ubuntu Desktop 14.04 on a desktop PC with a Nvidia GTX 660 connected to a HP LP2475w 24" monitor over DisplayPort.
It boots up fine, but if I switch off the monitor and switch it on again (for example at night) Ubuntu does not recognize the monitor at switch-on. Screen remains black, and the only way out is to reboot.
This is particularly annoying as I can and do switch the monitor to a different machine and back again, and the same thing happens. I have to reboot the Ubuntu machine to get the display back. Windows 8.1 manages this without an issue.
If I connect over DVI there is no problem; however, when I change to a 4K monitor I will need to use DP. Please help!
UPDATE
If I have a second monitor connected using DVI, I still loose the DisplayPort monitor if I switch it off and on again, but I am able to recover it by using Ctrl-Alt-F1 and then Ctrl-Alt-F7.
If the DisplayPort monitor is connected on its own, this method does not help. This is still a serious issue for me.
I can't believe no-one else is having it. Anyone care to share any experiences?
Do different graphics cards work better? Different monitors?