[Intel-gfx] Add hook to obtain the irq signal on HDMI connectivity

[Kavuri, Sateesh]

Hi,

I would like to add a hook to the i915 driver to get a signal whenever an external
connection is made, say a HDMI cable connection. Where would the right place be?
i915_irq.c?
Once I get a signal, I would have to read the EDID data (which I am already done 
with) and finally this connection needs to be signaled to the user space (for which
the functionality already exists).

Can someone point me to the right place?

Thanks,
Sateesh