Example #1
0
void setup_rx_bds(xemacpsif_s *xemacpsif, XEmacPs_BdRing *rxring)
{
    XEmacPs_Bd *rxbd;
    XStatus status;
    struct pbuf *p;
    u32_t freebds;
    u32_t bdindex;
    u32_t *temp;
    u32_t index = 0;

    if (xemacpsif->emacps.Config.BaseAddress != XPAR_XEMACPS_0_BASEADDR) {
        index = sizeof(s32_t) * XLWIP_CONFIG_N_RX_DESC;
    }

    freebds = XEmacPs_BdRingGetFreeCnt (rxring);
    while (freebds > 0) {
        freebds--;
        p = pbuf_alloc(PBUF_RAW, XEMACPS_MAX_FRAME_SIZE, PBUF_POOL);
        if (!p) {
#if LINK_STATS
            lwip_stats.link.memerr++;
            lwip_stats.link.drop++;
#endif
            printf("unable to alloc pbuf in recv_handler\r\n");
            return;
        }
        status = XEmacPs_BdRingAlloc(rxring, 1, &rxbd);
        if (status != XST_SUCCESS) {
            LWIP_DEBUGF(NETIF_DEBUG, ("setup_rx_bds: Error allocating RxBD\r\n"));
            pbuf_free(p);
            return;
        }
        status = XEmacPs_BdRingToHw(rxring, 1, rxbd);
        if (status != XST_SUCCESS) {
            LWIP_DEBUGF(NETIF_DEBUG, ("Error committing RxBD to hardware: "));
            if (status == XST_DMA_SG_LIST_ERROR)
                LWIP_DEBUGF(NETIF_DEBUG, ("XST_DMA_SG_LIST_ERROR: this function was called out of sequence with XEmacPs_BdRingAlloc()\r\n"));
            else
                LWIP_DEBUGF(NETIF_DEBUG, ("set of BDs was rejected because the first BD did not have its start-of-packet bit set, or the last BD did not have its end-of-packet bit set, or any one of the BD set has 0 as length value\r\n"));

            pbuf_free(p);
            XEmacPs_BdRingUnAlloc(rxring, 1, rxbd);
            return;
        }
        Xil_DCacheInvalidateRange((u32_t)p->payload, (u32_t)XEMACPS_MAX_FRAME_SIZE);
        bdindex = XEMACPS_BD_TO_INDEX(rxring, rxbd);
        temp = (u32_t *)rxbd;
        *temp = 0;
        if (bdindex == (XLWIP_CONFIG_N_RX_DESC - 1)) {
            *temp = 0x00000002;
        }
        temp++;
        *temp = 0;

        XEmacPs_BdSetAddressRx(rxbd, (u32_t)p->payload);
        rx_pbufs_storage[index + bdindex] = (s32_t)p;
    }
}
void
_setup_rx_bds(XEmacPs_BdRing *rxring)
{
	XEmacPs_Bd *rxbd, *CurBdPtr;
	int n_bds, i;
	XStatus Status;
	struct pbuf *p;
	u32 BdSts;
	unsigned int FreeBds, k;
	unsigned int BdIndex;
	unsigned int *Temp;

	FreeBds = XEmacPs_BdRingGetFreeCnt (rxring);
	Status = XEmacPs_BdRingAlloc(rxring, FreeBds, &rxbd);
	if (Status != XST_SUCCESS) {
		LWIP_DEBUGF(NETIF_DEBUG, ("setup_rx_bds: Error allocating RxBD\r\n"));
		return;
	}
	for (k = 0, CurBdPtr = rxbd; k < FreeBds; k++) {
		p = pbuf_alloc(PBUF_RAW, XEMACPS_MAX_FRAME_SIZE, PBUF_POOL);

		if (!p) {
#if LINK_STATS
			lwip_stats.link.memerr++;
			lwip_stats.link.drop++;
#endif
			LWIP_DEBUGF(NETIF_DEBUG, ("unable to alloc pbuf in recv_handler\r\n"));
			return;
		}
		BdIndex = XEMACPS_BD_TO_INDEX(rxring, CurBdPtr);
		Temp = (unsigned int *)CurBdPtr;
		*Temp = 0;
		if (BdIndex == (XLWIP_CONFIG_N_RX_DESC - 1)) {
			*Temp = 0x00000002;
		}
		Temp++;
		*Temp = 0;
		XEmacPs_BdSetAddressRx(CurBdPtr, (u32)p->payload);
		dsb();

		rx_pbufs_storage[BdIndex] = (int)p;
		CurBdPtr = XEmacPs_BdRingNext (rxring, CurBdPtr);

		/* Enqueue to HW */
	}
	Status = XEmacPs_BdRingToHw(rxring, FreeBds, rxbd);
	if (Status != XST_SUCCESS) {
		LWIP_DEBUGF(NETIF_DEBUG, ("Error committing RxBD to hardware: "));
		if (Status == XST_DMA_SG_LIST_ERROR)
			LWIP_DEBUGF(NETIF_DEBUG, ("XST_DMA_SG_LIST_ERROR: this function was called out of sequence with XEmacPs_BdRingAlloc()\r\n"));
		else
			LWIP_DEBUGF(NETIF_DEBUG, ("set of BDs was rejected because the first BD did not have its start-of-packet bit set, or the last BD did not have its end-of-packet bit set, or any one of the BD set has 0 as length value\r\n"));
		return;
	}
}
Example #3
0
XStatus init_dma(struct xemac_s *xemac)
{
	XEmacPs_Bd bdtemplate;
	XEmacPs_BdRing *rxringptr, *txringptr;
	XEmacPs_Bd *rxbd;
	struct pbuf *p;
	XStatus status;
	s32_t i;
	u32_t bdindex;
	volatile u32_t tempaddress;

	xemacpsif_s *xemacpsif = (xemacpsif_s *)(xemac->state);
	struct xtopology_t *xtopologyp = &xtopology[xemac->topology_index];

	/*
	 * The BDs need to be allocated in uncached memory. Hence the 1 MB
	 * address range allocated for Bd_Space is made uncached
	 * by setting appropriate attributes in the translation table.
	 * The Bd_Space is aligned to 1MB and has a size of 1 MB. This ensures
	 * a reserved uncached area used only for BDs.
	 */
	if (bd_space_attr_set == 0) {
		Xil_SetTlbAttributes((s32_t)bd_space, 0xc02); // addr, attr
		bd_space_attr_set = 1;
	}

	rxringptr = &XEmacPs_GetRxRing(&xemacpsif->emacps);
	txringptr = &XEmacPs_GetTxRing(&xemacpsif->emacps);
	LWIP_DEBUGF(NETIF_DEBUG, ("rxringptr: 0x%08x\r\n", rxringptr));
	LWIP_DEBUGF(NETIF_DEBUG, ("txringptr: 0x%08x\r\n", txringptr));

	/* Allocate 64k for Rx and Tx bds each to take care of extreme cases */
	tempaddress = (u32_t)&(bd_space[bd_space_index]);
	xemacpsif->rx_bdspace = (void *)tempaddress;
	bd_space_index += 0x10000;
	tempaddress = (u32_t)&(bd_space[bd_space_index]);
	xemacpsif->tx_bdspace = (void *)tempaddress;
	bd_space_index += 0x10000;

	LWIP_DEBUGF(NETIF_DEBUG, ("rx_bdspace: 0x%08x\r\n", xemacpsif->rx_bdspace));
	LWIP_DEBUGF(NETIF_DEBUG, ("tx_bdspace: 0x%08x\r\n", xemacpsif->tx_bdspace));

	if (!xemacpsif->rx_bdspace || !xemacpsif->tx_bdspace) {
		xil_printf("%s@%d: Error: Unable to allocate memory for TX/RX buffer descriptors",
				__FILE__, __LINE__);
		return ERR_IF;
	}

	/*
	 * Setup RxBD space.
	 *
	 * Setup a BD template for the Rx channel. This template will be copied to
	 * every RxBD. We will not have to explicitly set these again.
	 */
	XEmacPs_BdClear(&bdtemplate);

	/*
	 * Create the RxBD ring
	 */

	status = XEmacPs_BdRingCreate(rxringptr, (u32) xemacpsif->rx_bdspace,
				(u32) xemacpsif->rx_bdspace, BD_ALIGNMENT,
				     XLWIP_CONFIG_N_RX_DESC);

	if (status != XST_SUCCESS) {
		LWIP_DEBUGF(NETIF_DEBUG, ("Error setting up RxBD space\r\n"));
		return ERR_IF;
	}

	status = XEmacPs_BdRingClone(rxringptr, &bdtemplate, XEMACPS_RECV);
	if (status != XST_SUCCESS) {
		LWIP_DEBUGF(NETIF_DEBUG, ("Error initializing RxBD space\r\n"));
		return ERR_IF;
	}

	XEmacPs_BdClear(&bdtemplate);
	XEmacPs_BdSetStatus(&bdtemplate, XEMACPS_TXBUF_USED_MASK);
	/*
	 * Create the TxBD ring
	 */
	status = XEmacPs_BdRingCreate(txringptr, (u32) xemacpsif->tx_bdspace,
				(u32) xemacpsif->tx_bdspace, BD_ALIGNMENT,
				     XLWIP_CONFIG_N_TX_DESC);

	if (status != XST_SUCCESS) {
		return ERR_IF;
	}

	/* We reuse the bd template, as the same one will work for both rx and tx. */
	status = XEmacPs_BdRingClone(txringptr, &bdtemplate, XEMACPS_SEND);
	if (status != XST_SUCCESS) {
		return ERR_IF;
	}

	/*
	 * Allocate RX descriptors, 1 RxBD at a time.
	 */
	for (i = 0; i < XLWIP_CONFIG_N_RX_DESC; i++) {
		p = pbuf_alloc(PBUF_RAW, XEMACPS_MAX_FRAME_SIZE, PBUF_POOL);
		if (!p) {
#if LINK_STATS
			lwip_stats.link.memerr++;
			lwip_stats.link.drop++;
#endif
			printf("unable to alloc pbuf in init_dma\r\n");
			return ERR_IF;
		}
		status = XEmacPs_BdRingAlloc(rxringptr, 1, &rxbd);
		if (status != XST_SUCCESS) {
			LWIP_DEBUGF(NETIF_DEBUG, ("init_dma: Error allocating RxBD\r\n"));
			pbuf_free(p);
			return ERR_IF;
		}
		/* Enqueue to HW */
		status = XEmacPs_BdRingToHw(rxringptr, 1, rxbd);
		if (status != XST_SUCCESS) {
			LWIP_DEBUGF(NETIF_DEBUG, ("Error: committing RxBD to HW\r\n"));
			pbuf_free(p);
			XEmacPs_BdRingUnAlloc(rxringptr, 1, rxbd);
			return ERR_IF;
		}

		Xil_DCacheInvalidateRange((u32_t)p->payload, (u32_t)XEMACPS_MAX_FRAME_SIZE);
		XEmacPs_BdSetAddressRx(rxbd, (u32_t)p->payload);

		bdindex = XEMACPS_BD_TO_INDEX(rxringptr, rxbd);
		rx_pbufs_storage[bdindex] = (s32_t)p;
	}

	/*
	 * Connect the device driver handler that will be called when an
	 * interrupt for the device occurs, the handler defined above performs
	 * the specific interrupt processing for the device.
	 */
	XScuGic_RegisterHandler(INTC_BASE_ADDR, xtopologyp->scugic_emac_intr,
				(Xil_ExceptionHandler)XEmacPs_IntrHandler,
						(void *)&xemacpsif->emacps);
	/*
	 * Enable the interrupt for emacps.
	 */
	XScuGic_EnableIntr(INTC_DIST_BASE_ADDR, (u32) xtopologyp->scugic_emac_intr);
	emac_intr_num = (u32) xtopologyp->scugic_emac_intr;
	return 0;
}
XStatus init_dma(struct xemac_s *xemac)
{
	XEmacPs_Bd BdTemplate;
	XEmacPs_BdRing *RxRingPtr, *TxRingPtr;
	XEmacPs_Bd *rxbd;
	struct pbuf *p;
	XStatus Status;
	int i;
	unsigned int BdIndex;
	char *endAdd = &_end;
	/*
	 * Align the BD starte address to 1 MB boundary.
	 */
	char *endAdd_aligned = (char *)(((int)endAdd + 0x100000) & (~0xFFFFF));
	xemacpsif_s *xemacpsif = (xemacpsif_s *)(xemac->state);
	struct xtopology_t *xtopologyp = &xtopology[xemac->topology_index];

	/*
	 * The BDs need to be allocated in uncached memory. Hence the 1 MB
	 * address range that starts at address 0xFF00000 is made uncached
	 * by setting appropriate attributes in the translation table.
	 */
	Xil_SetTlbAttributes((int)endAdd_aligned, 0xc02); // addr, attr

	RxRingPtr = &XEmacPs_GetRxRing(&xemacpsif->emacps);
	TxRingPtr = &XEmacPs_GetTxRing(&xemacpsif->emacps);
	LWIP_DEBUGF(NETIF_DEBUG, ("RxRingPtr: 0x%08x\r\n", RxRingPtr));
	LWIP_DEBUGF(NETIF_DEBUG, ("TxRingPtr: 0x%08x\r\n", TxRingPtr));

	xemacpsif->rx_bdspace = (void *)endAdd_aligned;
	/*
	 * We allocate 65536 bytes for Rx BDs which can accomodate a
	 * maximum of 8192 BDs which is much more than any application
	 * will ever need.
	 */
	xemacpsif->tx_bdspace = (void *)(endAdd_aligned + 0x10000);

	LWIP_DEBUGF(NETIF_DEBUG, ("rx_bdspace: 0x%08x\r\n",
												xemacpsif->rx_bdspace));
	LWIP_DEBUGF(NETIF_DEBUG, ("tx_bdspace: 0x%08x\r\n",
												xemacpsif->tx_bdspace));

	if (!xemacpsif->rx_bdspace || !xemacpsif->tx_bdspace) {
		xil_printf("%s@%d: Error: Unable to allocate memory for TX/RX buffer descriptors",
				__FILE__, __LINE__);
		return XST_FAILURE;
	}

	/*
	 * Setup RxBD space.
	 *
	 * Setup a BD template for the Rx channel. This template will be copied to
	 * every RxBD. We will not have to explicitly set these again.
	 */
	XEmacPs_BdClear(&BdTemplate);

	/*
	 * Create the RxBD ring
	 */

	Status = XEmacPs_BdRingCreate(RxRingPtr, (u32) xemacpsif->rx_bdspace,
				(u32) xemacpsif->rx_bdspace, BD_ALIGNMENT,
				     XLWIP_CONFIG_N_RX_DESC);

	if (Status != XST_SUCCESS) {
		LWIP_DEBUGF(NETIF_DEBUG, ("Error setting up RxBD space\r\n"));
		return XST_FAILURE;
	}

	Status = XEmacPs_BdRingClone(RxRingPtr, &BdTemplate, XEMACPS_RECV);
	if (Status != XST_SUCCESS) {
		LWIP_DEBUGF(NETIF_DEBUG, ("Error initializing RxBD space\r\n"));
		return XST_FAILURE;
	}

	XEmacPs_BdClear(&BdTemplate);
	XEmacPs_BdSetStatus(&BdTemplate, XEMACPS_TXBUF_USED_MASK);
	/*
	 * Create the TxBD ring
	 */
	Status = XEmacPs_BdRingCreate(TxRingPtr, (u32) xemacpsif->tx_bdspace,
				(u32) xemacpsif->tx_bdspace, BD_ALIGNMENT,
				     XLWIP_CONFIG_N_TX_DESC);

	if (Status != XST_SUCCESS) {
		return XST_FAILURE;
	}

	/* We reuse the bd template, as the same one will work for both rx and tx. */
	Status = XEmacPs_BdRingClone(TxRingPtr, &BdTemplate, XEMACPS_SEND);
	if (Status != XST_SUCCESS) {
		return ERR_IF;
	}

	/*
	 * Allocate RX descriptors, 1 RxBD at a time.
	 */
	for (i = 0; i < XLWIP_CONFIG_N_RX_DESC; i++) {
		Status = XEmacPs_BdRingAlloc(RxRingPtr, 1, &rxbd);
		if (Status != XST_SUCCESS) {
			LWIP_DEBUGF(NETIF_DEBUG, ("init_dma: Error allocating RxBD\r\n"));
			return ERR_IF;
		}

		p = pbuf_alloc(PBUF_RAW, XEMACPS_MAX_FRAME_SIZE, PBUF_POOL);
		if (!p) {
#if LINK_STATS
			lwip_stats.link.memerr++;
			lwip_stats.link.drop++;
#endif
			LWIP_DEBUGF(NETIF_DEBUG, ("unable to alloc pbuf in recv_handler\r\n"));
			return -1;
		}

		XEmacPs_BdSetAddressRx(rxbd, (u32)p->payload);

		BdIndex = XEMACPS_BD_TO_INDEX(RxRingPtr, rxbd);
		rx_pbufs_storage[BdIndex] = (int)p;

		/* Enqueue to HW */
		Status = XEmacPs_BdRingToHw(RxRingPtr, 1, rxbd);
		if (Status != XST_SUCCESS) {
			LWIP_DEBUGF(NETIF_DEBUG, ("Error: committing RxBD to HW\r\n"));
			return XST_FAILURE;
		}
	}

	/*
	 * Connect the device driver handler that will be called when an
	 * interrupt for the device occurs, the handler defined above performs
	 * the specific interrupt processing for the device.
	 */
	XScuGic_RegisterHandler(INTC_BASE_ADDR, xtopologyp->scugic_emac_intr,
				(Xil_ExceptionHandler)XEmacPs_IntrHandler,
						(void *)&xemacpsif->emacps);
	/*
	 * Enable the interrupt for emacps.
	 */
	XScuGic_EnableIntr(INTC_DIST_BASE_ADDR, (u32) xtopologyp->scugic_emac_intr);
	EmacIntrNum = (u32) xtopologyp->scugic_emac_intr;
	return 0;
}
/**
*
* This function demonstrates the usage of the EMACPS by sending and
* receiving a single frame in DMA interrupt mode.
* The source packet will be described by two descriptors. It will be
* received into a buffer described by a single descriptor.
*
* @param	EmacPsInstancePtr is a pointer to the instance of the EmacPs
*		driver.
*
* @return	XST_SUCCESS to indicate success, otherwise XST_FAILURE.
*
* @note		None.
*
*****************************************************************************/
int EmacPsDmaSingleFrameIntrExample(XEmacPs *EmacPsInstancePtr)
{
	int Status;
	u32 PayloadSize = 1000;
	u32 NumRxBuf = 0;
	XEmacPs_Bd *Bd1Ptr;
	XEmacPs_Bd *Bd2Ptr;
	XEmacPs_Bd *BdRxPtr;

	/*
	 * Clear variables shared with callbacks
	 */
	FramesRx = 0;
	FramesTx = 0;
	DeviceErrors = 0;

	/*
	 * Calculate the frame length (not including FCS)
	 */
	TxFrameLength = XEMACPS_HDR_SIZE + PayloadSize;

	/*
	 * Setup packet to be transmitted
	 */
	EmacPsUtilFrameHdrFormatMAC(&TxFrame, EmacPsMAC);
	EmacPsUtilFrameHdrFormatType(&TxFrame, PayloadSize);
	EmacPsUtilFrameSetPayloadData(&TxFrame, PayloadSize);

	Xil_DCacheFlushRange((u32)&TxFrame, TxFrameLength);

	/*
	 * Clear out receive packet memory area
	 */
	EmacPsUtilFrameMemClear(&RxFrame);
	Xil_DCacheFlushRange((u32)&RxFrame, TxFrameLength);
	/*
	 * Allocate RxBDs since we do not know how many BDs will be used
	 * in advance, use RXBD_CNT here.
	 */
	Status = XEmacPs_BdRingAlloc(&
				      (XEmacPs_GetRxRing(EmacPsInstancePtr)),
				      1, &BdRxPtr);
	if (Status != XST_SUCCESS) {
		EmacPsUtilErrorTrap("Error allocating RxBD");
		return XST_FAILURE;
	}

	/*
	 * Setup the BD. The XEmacPs_BdRingClone() call will mark the
	 * "wrap" field for last RxBD. Setup buffer address to associated
	 * BD.
	 */

	XEmacPs_BdSetAddressRx(BdRxPtr, &RxFrame);

	/*
	 * Enqueue to HW
	 */
	Status = XEmacPs_BdRingToHw(&(XEmacPs_GetRxRing(EmacPsInstancePtr)),
				     1, BdRxPtr);
	if (Status != XST_SUCCESS) {
		EmacPsUtilErrorTrap("Error committing RxBD to HW");
		return XST_FAILURE;
	}

	/*
	 * Allocate, setup, and enqueue 2 TxBDs. The first BD will
	 * describe the first 32 bytes of TxFrame and the rest of BDs
	 * will describe the rest of the frame.
	 *
	 * The function below will allocate 2 adjacent BDs with Bd1Ptr
	 * being set as the lead BD.
	 */
	Status = XEmacPs_BdRingAlloc(&(XEmacPs_GetTxRing(EmacPsInstancePtr)),
				      2, &Bd1Ptr);
	if (Status != XST_SUCCESS) {
		EmacPsUtilErrorTrap("Error allocating TxBD");
		return XST_FAILURE;
	}

	/*
	 * Setup first TxBD
	 */
	XEmacPs_BdSetAddressTx(Bd1Ptr, &TxFrame);
	XEmacPs_BdSetLength(Bd1Ptr, FIRST_FRAGMENT_SIZE);
	XEmacPs_BdClearTxUsed(Bd1Ptr);
	XEmacPs_BdClearLast(Bd1Ptr);

	/*
	 * Setup second TxBD
	 */
	Bd2Ptr = XEmacPs_BdRingNext(&(XEmacPs_GetTxRing(EmacPsInstancePtr)),
				      Bd1Ptr);
	XEmacPs_BdSetAddressTx(Bd2Ptr,
				 (u32) (&TxFrame) + FIRST_FRAGMENT_SIZE);
	XEmacPs_BdSetLength(Bd2Ptr, TxFrameLength - FIRST_FRAGMENT_SIZE);
	XEmacPs_BdClearTxUsed(Bd2Ptr);
	XEmacPs_BdSetLast(Bd2Ptr);

	/*
	 * Enqueue to HW
	 */
	Status = XEmacPs_BdRingToHw(&(XEmacPs_GetTxRing(EmacPsInstancePtr)),
				     2, Bd1Ptr);
	if (Status != XST_SUCCESS) {
		EmacPsUtilErrorTrap("Error committing TxBD to HW");
		return XST_FAILURE;
	}

	/*
	 * Start the device
	 */
	XEmacPs_Start(EmacPsInstancePtr);

	/* Start transmit */
	XEmacPs_Transmit(EmacPsInstancePtr);

	/*
	 * Wait for transmission to complete
	 */
	while (!FramesTx);

	/*
	 * Now that the frame has been sent, post process our TxBDs.
	 * Since we have only submitted 2 to hardware, then there should
	 * be only 2 ready for post processing.
	 */
	if (XEmacPs_BdRingFromHwTx(&(XEmacPs_GetTxRing(EmacPsInstancePtr)),
				    2, &Bd1Ptr) == 0) {
		EmacPsUtilErrorTrap
			("TxBDs were not ready for post processing");
		return XST_FAILURE;
	}

	/*
	 * Examine the TxBDs.
	 *
	 * There isn't much to do. The only thing to check would be DMA
	 * exception bits. But this would also be caught in the error
	 * handler. So we just return these BDs to the free list.
	 */
	Status = XEmacPs_BdRingFree(&(XEmacPs_GetTxRing(EmacPsInstancePtr)),
				     2, Bd1Ptr);
	if (Status != XST_SUCCESS) {
		EmacPsUtilErrorTrap("Error freeing up TxBDs");
		return XST_FAILURE;
	}

	/*
	 * Wait for Rx indication
	 */
	while (!FramesRx);

	/*
	 * Now that the frame has been received, post process our RxBD.
	 * Since we have submitted to hardware, then there should be only 1
	 * ready for post processing.
	 */
	NumRxBuf = XEmacPs_BdRingFromHwRx(&(XEmacPs_GetRxRing
					  (EmacPsInstancePtr)), 1,
					 &BdRxPtr);
	if (0 == NumRxBuf) {
		EmacPsUtilErrorTrap("RxBD was not ready for post processing");
		return XST_FAILURE;
	}

	/*
	 * There is no device status to check. If there was a DMA error,
	 * it should have been reported to the error handler. Check the
	 * receive lengthi against the transmitted length, then verify
	 * the data.
	 */
	if ((XEmacPs_BdGetLength(BdRxPtr)) != TxFrameLength) {
		EmacPsUtilErrorTrap("Length mismatch");
		return XST_FAILURE;
	}

	if (EmacPsUtilFrameVerify(&TxFrame, &RxFrame) != 0) {
		EmacPsUtilErrorTrap("Data mismatch");
		return XST_FAILURE;
	}

	/*
	 * Return the RxBD back to the channel for later allocation. Free
	 * the exact number we just post processed.
	 */
	Status = XEmacPs_BdRingFree(&(XEmacPs_GetRxRing(EmacPsInstancePtr)),
				     NumRxBuf, BdRxPtr);
	if (Status != XST_SUCCESS) {
		EmacPsUtilErrorTrap("Error freeing up RxBDs");
		return XST_FAILURE;
	}

	/*
	 * Finished this example. If everything worked correctly, all TxBDs
	 * and RxBDs should be free for allocation. Stop the device.
	 */
	XEmacPs_Stop(EmacPsInstancePtr);

	return XST_SUCCESS;
}