Synchronization - Synchronization - 6.3 English - XD056

VVAS DMA-BUF memory uses the following cache-coherency flags:

VVAS_SYNC_TO_DEVICE

CPU wrote the buffer; flush before device read.

VVAS_SYNC_FROM_DEVICE

Device wrote the buffer; no CPU-to-device flush is required for another device reader.

PPE input synchronization:

• if VVAS_SYNC_FROM_DEVICE is not set, prepare_ppe_input_frame() sets VVAS_SYNC_TO_DEVICE and calls gst_vvas_memory_sync_bo();

• if VVAS_SYNC_FROM_DEVICE is set, the sync-to-device path is skipped;

• system-memory buffers have no sync flags and are handled through the internal copy path.

Inference input synchronization is delegated through vvas_videoframe_from_gstbuffer().

VVAS_SYNC_TO_DEVICE and VVAS_SYNC_FROM_DEVICE must not be set simultaneously.