xrandr does not "connect" to intel i915 HDMI output

right now i'm using ubuntu 16.04 with an additional KDE plasma5 dektop on a Pansonic FZ-g1 toughpad with an external gechic hdmi touchscreen

> lspci -ks 0:02 00:02.0 VGA compatible controller: Intel Corporation
> 3rd Gen Core processor Graphics Controller (rev 09)
>     Subsystem: Matsushita Electric Industrial Co., Ltd. 3rd Gen Core processor Graphics Controller
>     Kernel driver in use: i915
>     Kernel modules: i915

xrandr or sure also arandr does not show my hdmi port as connected

>     xrandr
>     Screen 0: minimum 8 x 8, current 3840 x 1200, maximum 32767 x 32767
>     eDP1 connected primary 1920x1200+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
>        1920x1200     60.00*+  59.95  
>     .......
>     DP1 disconnected (normal left inverted right x axis y axis)
>     HDMI1 disconnected 1920x1200+1920+0 (normal left inverted right x axis y axis) 0mm x 0mm
>        1920x1200     60.00*
>     VGA1 disconnected (normal left inverted right x axis y axis)
>     VIRTUAL1 disconnected (normal left inverted right x axis y axis)

but i managed to trick x with following lines and the touchscreen shows with black background, but works pretty well as dual monitor now

> xrandr --addmode HDMI1 "1920x1200" xrandr --output HDMI1 --mode
> "1920x1200" --right-of eDP1

my problem is that the touch calibration does not seem to work for two displays if x just knows one as connected ? so i do the following to map the internal display to the internal touch [CODE]xinput map-to-output 15 eDP1[/CODE] Ok, that works and the internal touchscreen is quite precise now. But doing this with the not connected hdmi touchscreen gives following error

> xinput map-to-output 20 HDMI1 Unable to find output 'HDMI1'. Output
> may not be connected.

that makes the external touchscreen unusable cause it makes the curser jump to the internal display, or anyway in some random way, but not where i actually touch

so i think the solution with forcing x to display the second monitor to show is not the solution, cause it's neither "design integrated" in unity or plasma nor arandr and other graphical convenient tool recognize the second display.

i tried the following unit not FIRST: added following grub bootoption

> i915.modeset=1

SECOND: installed intel driver with a tricking ubuntu 16.04 to be 15.10 https://01.org/linuxgraphics/downloads/intel-graphics-installer-linux-1.4.0 THIRD: added following xorg.conf (not knowing if xorg.conf is even used anymore)

> Section "Device"
>     Identifier "card0"
>     Driver "intel"
>     VendorName  "Intel Corporation"
>     BoardName   "Intel Corporation N10 Family Integrated Graphics Controller"
>     BusID       "PCI:0:2:0"
>     Option      "SwapbuffersWait"    "false" EndSection

any ideas either getting x to connect to the hdmi port or to "force" mapping the touchscreen to the hdmi output by something like "xinput map-to-output 20 HDMI1" ?

thanks in advance

gernot