Update to this question - it looks like the window manager could be part of my solution.
I noticed that in XFCE hotplugging the monitor always left me with a blank screen, but if I switch to GNOME then the hotplug does not loose video which is good.
Problem is that still the bootup without a screen results in nothing (user is set to autologin in gnome) and the only way to resolve this is to login via a remote session and restart GDM (or issue an init 3 && init 5 which I suppose restarts GDM). It is worth noting that in this remote ssh terminal if I run xrandr -d :0 it lists the monitor as detected, so the driver seems to detect it, it is just that GDM never sets it up.
I suppose a total hack would be to try to get a script to run when the monitor is detected for the first time after and perform a restart of GDM, just need to figure out how to do this, perhaps UDEV is the answer?
Apologies for putting this question into the installer discussion but for some reason there is no "New Topic" button in the other section of this forum.
I have a situation that I need to resolve and cant seem to get it right.
My situation is this: I have a MythTV PVR system running in my house and the main backend/frontend is running on an old AMD board with built in Nvidia graphics, problem is that this board is starting to pack up.
I ordered a new Skylake board (B150 chipset) with a Skylake processor with the intnetion of replacing the AMD board with this.
My problem is tht the system connects to the TV via a Home Theater AMP which has built in HDMI switching. This means that the HDMI is essentially hot plugged every time we switch sources as well as that the PC does not necessarily start with a HDMI connection active.
With regard to the hot plugging, this seems to be working out the box with Fedora 23 and the latest Intel Drivers (MythBuntu 16.04 cant say that unfortunatly), however the problem of the system starting without HDMI and then later having HDMI connected does not work.
With the nvidia driver I resolved this with a line in xorg.conf Option "ConnectedMonitor" "DFP" as well as passing in the EDID of the TV that I extracted earlier. I tried this with the intel driver but I see in the Xorg log that the Intel driver does not use the ConnectedMonitor line.
Is there any way to resolve this?? Either by forcing video out of the HDMI always like I used to do or getting the dynamic detection to work correctly??
Thanks in advance
Anthony