[PATCH 1/6] drm: add writeback pointers to drm_connector

[Kandpal, Suraj]

Hi Dmitry,
Thanks for your comments
 
> Could you please clarify, why do you want to use intel_connector for the
> writeback connector?
> I can see a usecase for sharing an encoder between the display and writback
> pipelines (and if I'm not mistaken, this is the case for Abhinav's case).
> However, sharing the hardware-backed connector and writeback connector
> sounds like a sign of a loose abstraction for me.
> 
> Please correct me if I'm wrong and Intel driver would really benefit from
> reusing intel_connector as a base for drm_writeback_connector.
> 

The thing is drm_writeback_connector contains drm_connector and drm_encoder fields
which get initialized when we call drm_writeback_connector_init adding the connector
to the list of connectors for the drm_device.
Now if I decide not to wrap drm_writeback_connector with intel_connector the issue
is I'll have to add a lot of checks all over the driver to see if the drm_connector is actually
present inside intel_connector or not. I don’t see the point of not having drm_writeback_
connector as even though it’s a faux connector we still treat is as a connector and it would
be better for us to use intel_connector for writeback_connector.
Also the current drm_writeback_connector structure kind of restricts drivers consequently
dictating how they implement their writeback functionality, as a midlayer I don't feel that
would be the right approach as drivers should have the freedom to develop their own flow
to implement the functionality and use the midlayer as a helper to get that done. 

Best Regards,
Suraj Kandpal