Linux/TDA2EXEVM: [External ] AVB camera packet be dropped by Sequence number broken

Hi
Are you using AVB cameras or AVB talker as input data source?
Can you use all the tools (versions) and Linux Kernel, uboot as specified by VSDK user guide - \vision_sdk\docs\Linux\VisionSDK_Linux_UserGuide.pdf. Any deviation from this is untested and may result in demo application failure.
This user guide has a section, explains - how to build and run AVB on VSDK Linux, please follow the same

regards, Shiju

Hi Shiju,

Thank you for your feedback.

We used 4 CH AVB camera as the input data source, and confirmed that the User guide described, the AVB talker works fine. 

We observed that the comments of AVBTP_processRxPackets() [ \avbtp_0_10_00_00\packages\ti\avbtp\avbtp.c]

 /* we only care about broken sequences after we find the JPEG SOI marker.
                * If this packet happens to contain it, then don't drop it
                */    

/* * TODO: In the future, we may have to deal with SOI flags that do not
     *        appear at the start of the payload.
     */

Could you help let me know how to handle the packet without SOI flag? Thanks.

BR,

Sam Hsieh.

Hi Sam
Ok, thanks for confirming that the UC works with AVB talker.
WRT your query on SOI flag, will check and get back to you

regards, Shiju

Hi Shiju,

Is there any updates on it?

As the avbtp_0_10_00_00_user_guide described:
I observed that TDA2 default enable JPEG Restart marker detection flag to lower the system latency during AVBRX initialization.
If there is no JPEG marker in the payload, how avbtp_task(avb_handle) notify client Restart JPEG?
Otherwise all AVB packets will be dropped by broken equence number.

Is it possible caused by CPDMA buffer is not enough?
I ever have tried to increase the AVB2NSP_RX_PACKETS (64-> 128),
but it results in the memory fauts. It seems that there is some dependencies among AVBTP library, GWMAC and CPDMA modules.
Could you teach me how to increase listener the count of AVB2NSP_RX_PACKETS? Thanks.


regards,
Sam Hsieh

Hi Shiju,

Could you help update the SOI flag? Thanks.

BTW, we tested some scenarios with various combinations:

AVB[#1]: normal AVB(8081), send one packet frame per 2ms.

AVB[#2]: Fast AVB(8061), send one packet frame per 0.7ms

OK: It means that no broken sequence occurred; NG: it means that broken sequence occurred often

case		combinations	result
1		4 CH AVB[#1]	OK
2		4 CH AVB[#2]	NG
3		3 CH AVB[#1] & 1 CH AVB[#2]	NG
4		1 CH AVB[#2]	OK

We also tried to increase the quantity of buffer (AVB_RX_LINK_BUFS_PER_TALKER_DEFAULT, 6 -->16),

But the issue broken Sequence occurred often.

Could you help teach us how to look into the issue of broken sequence? Thanks.

regards,

Sam Hsieh

Hello Sam,

For broken sequence, what is CPU load? Also did you check AVB statistics to see if there was buffer underflow encountered?

Regards,
Prasad

Hi Prasad,

As we observed that the CPU (M4)  System load is around 45~50%, didn't see the buffer underflow phenomenon occurred.

I tried to change the CPDMA configuration of rxInterruptsPerMsec = 1 (per 1ms). but it is not helpful for the sequence broken.

Could you teach me how to identify the all AVB Sequence packets are received in nsp_gmacsw driver module? Thanks.

BR,

Sam Hsieh

Hello Sam,

AVB module maintains statistics of all drop count etc. in avb2NspStats structure.

If you have CCS connection, just put this variable into the "expressions window" and observe which count increases. Hopefully this will give some idea where drop happens and why.

To enable statistics, set below to true in your config file.

AVBTP.instrumentedBuild = true;

typedef struct AVB2NSP_STATS_
{
    AVB2NSP_PacketTaskStats rxStats;
    AVB2NSP_PacketTaskStats txStats;
    AVB2NSP_ProcessingStats procStats;
#if defined(AVBTP_INSTRUMENTATION_ENABLED)
    uint32_t rxReadyAVBTPPacketEnqueue;
    uint32_t rxReadyAVBTPPacketDequeue;
    uint32_t rxFreeAVBTPPacketEnqueue;
    uint32_t rxFreeAVBTPPacketDequeue;

    uint32_t txReadyAVBTPPacketEnqueue;
    uint32_t txReadyAVBTPPacketDequeue;
    uint32_t txFreeCPDMAPacketEnqueue;
    uint32_t txFreeCPDMAPacketDequeue;

    uint32_t etherTypeError;
    uint32_t controlDataPacketCount;
    uint32_t streamIDValidFlagError;
    uint32_t avbSubTypeError;
    uint32_t invalidStreamIDError;
    uint32_t invalidPacketSizeError;
    uint32_t noBuffersAvailable;
    uint32_t outOfSequenceError;
    uint32_t insufficientSizeError;
#endif
    uint32_t txFreeCPDMAPacketUnderflow;
    uint32_t txDroppedPacketCount;
    uint32_t txFreeAVBPacketQueueUnderflow;
}
AVB2NSP_Stats;

Regards,

Prasad

Hi Prasad,

Thank you for your feedback.

Yes, I configured the "AVBTP.instrumentedBuild = true",

but I have no experience in the CCS tools on the TDA2XX board.

Could you help teach me

How to setup the connection between DUT and PC (Linux)? Thanks.

BR,

Sam.

I haven't heard back from you, I'm assuming you were able to resolve your issue.
If not, just post a reply below (or create a new thread if the thread has locked due to time-out).

Hi Prasad,

I still stock in the issue which result from the bandwidth limitation of TDA2X and SWITCH.

I estimate the bandwidth requirement per channel AVB camera (100BASET) without Image distortion about 50Mbps.

Even though the Ethernet MAC could support 1Gbps, because Both TDA2X and AVB camera don't support  Stream Reservation Protocol (SRP),

it means that  A data stream associated with a stream reservation guaranteed latency &Bandwidth.

It results in the AVB packet could be dropped.

Could you help teach me how to solve the issue ? Thanks.

regards,

Sam Hsieh

Hello Sam,

Can you please let me know the contents of statistics registers? (address 0x4848-4900 to 0x4848-4990)

Regards,
Prasad

Any update?

Hi Jondhale,

Sorry reply for late.

The issue doesn't be fully solved,  the root cause could not be identified yet, perhaps be related to the bandwidth of SWITCH.

Because I am not familiar with the CCS tools,

Could you help teach me how to  get statistics registers? (address 0x4848-4900 to 0x4848-4990)? Thanks.

Thank you for your support.

regards,

Sam Hsieh