Multi Channel DMA Intel® FPGA IP for PCI Express User Guide

ID 683821
Date 10/29/2021
Public

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8.1.6.12. ifc_qdma_request_prepare

Table 83.  ifc_qdma_request_prepare
API API Description Input Parameters Return Values
int ifc_qdma_request_prepare(struct ifc_qdma_channel *qchnl, int dir, struct ifc_qdma_request *r);

Depending on the direction, application selects the queue and prepares the descriptor but not submit the transactions. Application must use ifc_qdma_request_submit API to submit the transactions to DMA engine.

qchnl: channel context received on ifc_qchannel_get()

dir: DMA direction, one of IFC_QDMA_DIRECTION_*

r: request struct that needs to be processed

Returns the number of transactions completed.

negative otherwise