AM5716: PRU-ETH unavailable, Can not Send/Recv any packet.

Hi, Tanmay

Hi,

The setup is not very clear to me. From my understanding, this is what is happening:

• PRU are running the PRU ETH binaries
• A15 is connecting to the PRU cores and creating the eth3 interface
• A15 is also running an IPC application forwarding traffic to DSP
• DSP is running IPC application receiving the PRU traffic

Can you confirm this is what is happening.

Regards,
Tanmay

• PRU are running the PRU ETH binaries
• DSP is receiving/sending traffic using  ICSS EMAC low level driver.
• DSP is runing ethercat stack, but I believe the issue I encountered is unrelated to the EtherCAT protocol stack.
• DSP is running IPC application.
• A15 is also running an IPC application.
• During the Linux startup of A15, eth3 is disabled: ifconfig eth3 down.
• IPC between A15 and DSP is used to transmit application data as well as instructions.

• A15 is connecting to the PRU cores and creating the eth3 interface.
• Connect eth3 to the laptop's Ethernet port.
• Sending packets on a laptop

• Use ethtool to check the statistics for eth3.

Hello zhijie 

     what's the status of this issue?

Regards

   Semon

Hi,

So this is only seen on multiple hardwares?

Regards,
Tanmay

Hi, Tanmay

I didn’t quite understand what you meant by “multi-hardware,” but this issue still troubles me because I need to use two PRU-ETH interfaces simultaneously.

Regards,

Zhijie

Today, I made some new discoveries that might better describe the issue I am encountering. When using PRU-ETH to send packets on the DSP, the function ICSS_EmacTxPacketEnqueue in the source code file icss_emacdrv.c reported an error with the return value: ICSS_EMAC_ERR_TX_OUT_OF_BD. The comment provided is as follows:

#define ICSS_EMAC_ERR_TX_OUT_OF_BD                     (ICSS_EMAC_SWITCH_ERROR_MAJOR + 8u)
/**< Tx ran out of Buffer descriptors to use.                               */

At the same time, I added debugging logs, and the specific function is as follows:

/*Check if queue is full and there is an wrap around */
#if defined(ICSS_EMAC_DEBUG) && (ICSS_EMAC_DEBUG > 2)
    printf_INFO("P+%d,HWREG(0x%x) = 0x%x,wr_ptr=0x%x,size=0x%x,rd_ptr=0x%x, desc_off=0x%x\n",portNumber, temp_addr, temp, queue_wr_ptr, size, queue_rd_ptr, txQueue->buffer_desc_offset);
#endif
    if (((queue_wr_ptr + 4U) % size) == 0U)
    {
        if (queue_rd_ptr == txQueue->buffer_desc_offset) /* Since queue is not starting from 0. */
        {
            txQueue->qStat.errCount++;
            if (emacMode == 0U)
            { /*Switch Mode*/
                temp_addr = ((((ICSS_EmacHwAttrs *)icssEmacHandle->hwAttrs)->emacBaseAddrCfg)->dataRam1BaseAddr + txQueue->queue_desc_offset + 4U);
                HWREGB(temp_addr) = 0;
            }
            else
            {
                temp_addr = (pruSharedMem + txQueue->queue_desc_offset + 4U);
                HWREGB(temp_addr) = 0U;
            }
            hostStatPtr->txDroppedPackets++;
            printf_INFO("--ICSS_EMAC_ERR_TX_OUT_OF_BD(-1)=0x%x, M:0x%x + 8 \n", ICSS_EMAC_ERR_TX_OUT_OF_BD, ICSS_EMAC_SWITCH_ERROR_MAJOR);
            return ((int32_t)ICSS_EMAC_ERR_TX_OUT_OF_BD); /* No space in queue */
        }
    }

The debug logs at the time of the error are as follows:

P+1,HWREG(0x4b281ed8) = 0x162c14ac,wr_ptr=0x162c,size=0x1630,rd_ptr=0x14ac, desc_off=0x14ac

?? ? said:

The issue is still troubling me, but when I switch to another PRU-ETH network interface, I almost never encounter this problem again.

Hello Zhijie

    is there any difference for the two network interface? why one is good, and another can't work

Regards

   Semon

?? ? said:

As far as I know, the two network interface are not different.

The information I provided earlier spans a long period and, due to my limited understanding of the issue at the time, may not accurately describe the problem. 

I have started a new thread to explain the issue. see PRU-ETH unavailable in DSP core, Can not Send/Recv any packet

Hello Zhijie

    so we can discuss in the new case, this case will be closed

Regards

   Semon