Writeback for assertive display feature is needed only for
split displays and only if ro.qcom.ad is set to 2 by OEM.
This patch removes the unnecessary code and adds the relevant
conditional checks for split displays and property value
Change-Id: Ic36f28441d1a6e93132316b33fe1cf98a6e1efe4
Add assertive display support to hwc. This feature takes effect when
node /sys/class/graphics/fb*/ad is present. This signifies that that LM0
is being used with fb* for writeback.
When a video playback begins we write "1" to this node to indicate to
post processing that a writeback will happen. Likewise a "0" is written
to this node when playback stops.
The original contents are worked upon and the modified output is fed
via writeback to either rotator or mdp as appropriate.
The feature doesnt trigger when either:
1) Buffer size exceeds 2048
2) External display is connected
3) Multiple yuv streams are present
When this mode is active, MDP comp is applied only to yuv layer.
Change-Id: If5520f9dc849de3189c9f9ed4e9072c8f8f760e1
