I'm using two P2715Q displays - one with docked Dell Precision M4800 and the other with docked HP 840 G2. On "all Dell" setup all runs smoothly, but paired with HP I have problems with the monitor in sleep mode.
Whenever the monitor goes to sleep (e.g. I log off the system but don't shut it down), it keeps waking up (or at least displaying "Entering power save mode" message) every couple of seconds for the whole time. The same - surprisingly! - happens when I shut down the system. It looks some signal may reach the monitor anyway...
Previously I used a HP monitor with my HP setup and it had no problems with sleep mode, so I don't think there are any problems with the laptop / docking station themselves.
I've already tried disabling DDC/CI (some forum users suggested it resolved their problems), but it hasn't worked for me.
Are there any other solutions I could try?