Support for early wakeup in DRM

[jsanka at codeaurora.org]

Hello All, 

I am seeking recommendations for DRM compatible methods of updating the HW
other than frame commit path. When exiting idle/runtime_suspend, the driver
votes for a bunch of resources including power/clk/bandwidth as a part of
first commit handling. This usually adds a few millisecond delay before
processing the frame. The requirement is to find possible ways to reduce
this delay by providing an early intimation to the framework to "prepare"
the HW by voting for the resources and keep the HW ready to process an
imminent frame commit. Especially in performance oriented Automotive world,
these delays are very time critical and we are working on ways to mitigate
them.  

 

DRM framework converges all the parameters affecting the HW in terms of DRM
properties in a single COMMIT call. To address the above issue, we need a
parallel channel which should allow the framework to make necessary changes
to the HW without violating the master access privileges. 

 

Before resorting to custom downstream ways, I want to check with the
community for folks who might have encountered and resolved such issues.

 

Thanks and Regards,

Jeykumar S

Qualcomm Inc.

 

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