Is drmWaitVBlank() or drmModePageFlip necessary after drmModeSetPlane()

Hello all, Recently, I meet a performance problem with drmModeSetPlane(), it works quite slow with drm_atomic_commit(), I have to force it use drm_atomic_async_commit() for drmModeSetPlane() which modifies the drm base system. I want to optimize the performance in standard way, so I think I could move those sync job to one of drmWaitVBlank() or drmModePageFlip. But I found most of atomic_commit() would have a sync internal, waiting vbank. So those functions like drmWaitVBlank() or drmModePageFlip are not necessary after drmModeSetPlane()?