Request for feedback - Sprite flip notification support

[Vijay Purushothaman <vijay.a.purushothaman@intel.com>]

Hello,

In our current driver implementation we support flip notifications only 
for primary plane. So, in a full screen video playback scenario where 
only one sprite plane is active, the user space is forced to rely on 
primary plane flip notification even though there is no real need for 
this plane to be active. Ideally we should be able to support flip 
notifications for any given plane. Switching off the primary plane (when 
not used) will help in better memory self refresh & decent power savings..

We do have a hack in android product trees which supports flip 
notifications for one sprite plane. unfortunately this hack in its 
current form cannot be considered for up streaming...

My current thinking is to have an array of unpin_work items to match the 
number of planes. Is anyone working on this or thought about this 
scenario in detail? Any pointers / restrictions that needs to considered 
for a generic implementation of this feature?

*Thanks,
Vijay
*