screen flicker on rockchip platform.

Hi,
I had tried this project on rockchip platform using h264_rkmpp decoder.
The screen flickered and only few frame can be displayed.
I have tried to add time-delay(about 20ms) between drmModeSetPlane and drmModeRmFB. Then the flicker alleviated.
I know the modification above is not a good method and i want to resolve the flicker problem in a appropriate way. Can you help me?
Thanks!