hdmi output not detected by xrandr

[sashan]

Hi

I'm trying to figure out why the external hdmi output on my laptop doesn't work
but am not sure where the problem is or if this is the right mailing list. I've
posted on distribution specific forums asking the same question but there hasn't
been any response that leads to a fix. As far as understand xrandr should be
able to detect an external monitor irrespective of what is in the xorg.conf
file.

This is the output from xrandr when the monitor is connected to the laptop over
the hdmi cable:

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
LVDS1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
   1920x1080      60.0*+   40.0 
   1400x1050      60.0 
   1280x1024      60.0 
   1280x960       60.0 
   1024x768       60.0 
   800x600        60.3     56.2 
   640x480        59.9 
VGA1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)

Only the laptop's display is detected. 

The vga controllers on the laptop are:

01:00.0 VGA compatible controller: nVidia Corporation Device 0df5 (rev a1) (prog-if 00 [VGA controller])
    Subsystem: Dell Device 0446
    Flags: bus master, fast devsel, latency 0, IRQ 16
    Memory at f0000000 (32-bit, non-prefetchable) [size=16M]
    Memory at c0000000 (64-bit, prefetchable) [size=256M]
    Memory at d0000000 (64-bit, prefetchable) [size=32M]
    I/O ports at 3000 [size=128]
    Expansion ROM at f1000000 [disabled] [size=512K]
    Capabilities: <access denied>
    Kernel driver in use: nouveau
    Kernel modules: nvidiafb, nouveau00:02.0 VGA compatible controller:

Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])
    Subsystem: Dell Device 0446
    Flags: bus master, fast devsel, latency 0, IRQ 49
    Memory at f1400000 (64-bit, non-prefetchable) [size=4M]
    Memory at e0000000 (64-bit, prefetchable) [size=256M]
    I/O ports at 4000 [size=64]
    Expansion ROM at <unassigned> [disabled]
    Capabilities: <access denied>
    Kernel driver in use: i915
    Kernel modules: i915

Any pointers about the correct diagnoistic path to take would be great.

Thanks