DRM: how to support live source

[Ginny Chen]

Dear All:

I am Ginny Chen from Mediatek company.I start to work with DRM for a 
while and now I am evaluating our display architecture for our new SoC.
I would like to adopt DRM to develop our display driver. 
However, in our new SoC, the input source of display engine could be 
memory or direct-linked with other hardwares (ex:camera sensor) which 
means the input source of each plane should be able to configure during 
plane updating.
As my understanding,with currently DRM framework, the input source of 
plane could only be framebuffer that implies we still need to allocate 
framebuffer for planes which are direct-linked with other hardware 
engines if I want to control planes without modifying DRM framework.
It will waste memory and doesn't make sense for user to notice/manage 
the framebuffers for direct-linked DRM planes.
Do you have any ideas for such use case?
Any suggestion will be very appreciated.

Regards,
Ginny Chen