Loosing interrupts on queue and semaphore

Kernel
1

nobody wrote on Wednesday, November 02, 2005:

Hello,
i am working  at a CAN application which reads from multiple CAN interfaces by interrupt, and releases a semaphore (…i also tried a queue) to notify a task. I am loosing up to 30% of my CAN-interrupts.
When i remove the queue/semaphore functions everything seems to be ok.

Port : ARM7
Hardware LPC2294  

Any Idea ???

 
Thanx,

Peter

2

nobody wrote on Wednesday, November 02, 2005:

How fast is the LPC running?  (MHz, waitstates, etc), and what is the baud of the CAN?

Are you able to post your ISR code with and without the queues?

3

nobody wrote on Thursday, November 03, 2005:

Hello,

the LPC is running with 48 MHz, (… i also tried 60MHz). The behavior is the same at internal an external RAM.

CAN-Baudrate is 500Kbps

The CAN-ID’s are sent in 1 ms 25% Bus-Load,
10 ms (3% Busload) and 100ms (0,3 % Busload)
There are no bursts at the Bus (checked with Vector-CANalyzer)

The problems occure at 1 and 10 ms    

static portCHAR can_isr(unsigned int can_nr)
{
//    portBASE_TYPE xTaskWoken = pdFALSE;
/* put data it inside CAN-Ringbuffer */
    if(LPC_CAN[can_nr]->ctrl.gsr.dw & 0x1) {
        can_buffer->recv_ringb[can_nr].entries[can_buffer->recv_ringb[can_nr].w_ptr].can.id.dw =
            LPC_CAN[can_nr]->rcv.id.dw;
        can_buffer->recv_ringb[can_nr].entries[can_buffer->recv_ringb[can_nr].w_ptr].can.data[0].dw =
            LPC_CAN[can_nr]->rcv.data[0].dw;
        can_buffer->recv_ringb[can_nr].entries[can_buffer->recv_ringb[can_nr].w_ptr].can.data[1].dw =
            LPC_CAN[can_nr]->rcv.data[1].dw;
        can_buffer->recv_ringb[can_nr].entries[can_buffer->recv_ringb[can_nr].w_ptr].ts =
            T0_TC;
    /* release CAN-message */
        LPC_CAN[can_nr]->ctrl.cmr.b[0] = 0x4;
    /*Ring buffer movement*/   
        can_buffer->recv_ringb[can_nr].w_ptr ++;   
        if(can_buffer->recv_ringb[can_nr].w_ptr >= CAN_RING_SIZE) {
            can_buffer->recv_ringb[can_nr].w_ptr = 0;
        }
        can_rx_cnt[can_nr]++;
//        xTaskWoken = xSemaphoreGiveFromISR(CanIrqSem, xTaskWoken );
//        xTaskWoken = xQueueSendFromISR(CanIrqQ,&can_nr, xTaskWoken);
    }
    if(LPC_CAN[can_nr]->ctrl.gsr.dw & 0x2) {
        can_buffer->recv_ringb[can_nr].ovrcnt++;
        LPC_CAN[can_nr]->ctrl.cmr.b[0] =  0x8;
    }
    return pdFALSE;
//    return xTaskWoken;
}

void can0_rx_isr(void)
{
    portENTER_SWITCHING_ISR();
    portBASE_TYPE xTaskWoken = pdFALSE;
    xTaskWoken = can_isr(0);
    /* acknowledge Interrupt */   
//    VICVectAddr = 0x0L;
    VICVectAddr = 0xFFFFFFFFL;
    /*return from ISR by switching or recovering */
    portEXIT_SWITCHING_ISR(xTaskWoken);
}

Thankx,

Peter