i.MX RT 1176 FlexCAN FiFo EDMA transfer QUEUESEND USAGE

[Vivekananda]

Hi, 

i am uisng FIFO Edma transfer for the recieving the can data via call back function.

problem is that i am not able use xQueueSendFromISR or xQueueSend functions in call back function. 

following is the function implememtation.

static void CAN_DMA_Callback(CAN_Type *base, flexcan_edma_handle_t *handle, status_t status, void *userData)

{

(void)base;

(void)handle;

hal_can_t * pHanCb = (hal_can_t * )(userData);

BaseType_t xHigherPriorityTaskWoken = pdFALSE;

    /* Process FlexCAN Rx event. */

    if (kStatus_FLEXCAN_RxFifoIdle == status)

    {

    for (uint32_t i = 0; i < RX_MESSAGE_NUM; i++)

        {

    pHanCb->iIsDataReceived = 1;

pHanCb->sMsg[i].iEventId =0;

if(pHanCb->qRxMsg != NULL)

{

if(pdFALSE == xQueueIsQueueFullFromISR(pHanCb->qRxMsg))

{

memcpy(&pHanCb->sMsg[i].sRxFrame,&rxFrame[i],sizeof(flexcan_frame_t));

bool rval = xQueueSendFromISR(pHanCb->qRxMsg,

(void*)(&(pHanCb->sMsg[i])),

&xHigherPriorityTaskWoken);

if( rval != pdPASS )

{

NVIC_ClearPendingIRQ(pHanCb->IRqn);

}

}

else

{

PRINTF("\r\n The Data Queue is FULL\r\n");

}

}

        }

        /* Receive data through Rx FIFO. */

        pHanCb->rxFifoXfer.frame    = &rxFrame[0];

        pHanCb->rxFifoXfer.frameNum = RX_MESSAGE_NUM;

        (void)FLEXCAN_TransferReceiveFifoEDMA(pHanCb->pCanType, &pHanCb->hFlexcanEdmaHandle, &pHanCb->rxFifoXfer);

    }

}

[mayliu1]

Hi @Vivekananda ,

Thank you so much for your interest in our products and for using our community.

There are two key pointes need to check in your code:

1: Your CAN_DMA_Callback is called from an EDMA interrupt context. So In this case, you must use xQueueSendFromISR (not xQueueSend).

2: After calling xQueueSendFromISR, you need to check the xHigherPriorityTaskWoken flag and call portYIELD_FROM_ISR(xHigherPriorityTaskWoken). 

Wish it helps you.
If you still have question about it, please kindly let me know.

Best Regards

MayLiu