AM3359: CPSW's DMA sometimes doesn't sent out the packet.

Hello Nathan,

What is the version of the software you are running? Do you mean Starterware? Do you have plan to upgrade it to Processor SDK? Please take  a look at below link:

https://e2e.ti.com/support/legacy_forums/embedded/starterware/f/790/t/628801?tisearch=e2e-sitesearch&keymatch=starterware

best regards,

David Zhou

Hi David,
I used the STARTERWARE in the newest PDK for am335x. I am implementing my own SBL with Ethernet function, so I only use internal RAM. It’s not possible to use TI-RTOS and NDK.
Do you know any possible setting or operations might cause this situation? It seems like the data memory is not available to DMA.
Thanks.
Nathan

Hi,

Does the order matter? E.g, i you first wrote 0x4a102010 to TX0 HDP, will this work?
Or the buffer pointer matter? E.g., if you wrote 0x4a102000 to TX0 HDP, with buffer pointing to 0x403072a, will this work?
Or the buffer content matter? E.g., if you replace the working case buffer contents to the failure one, will this work? You have a length of 0x3C. The working one looks to be a MAC/IPV4 packets (I saw 0008 0045), what is the protocols of the failure one? Maybe the Wireshark can't recognize it and can't capture/display it properly?

Regards, Eric

Hi,
Only buffer pointer matters. I can still send data with pointing to other memories.
The unavailable memory is not able to be sent by other channel or CPPI memory as well.
WireShark can catch packets even the packet is meaningless.
So, the unavailable memory seems like be locked/occupied or other reason that I don't know.

Regards, Nathan

Hi,

Do you mean:
0x4a102010 0x40307336 0000003c e000003c worked? But
0x4a102010 0x4030702a 0000003c e000003c failed?

I don't see any relevance of those two addresses. It just sends out certain bytes of data from either address. How those two buffer addresses are allocated? Is that from your application?

Regards, Eric

Hi,
Yes, that's what I mean.
These two buffers are located by my application.

In my case, 0x4030702a is only failed in specific situations (I don't actually know what the "situation" is), because the only specific packet was not sent but I used the data buffer.

I refer to an old lwIP application in am335x_sysbios_ind_sdk_01.01.02.01 and try to migrate it to be a SBL because it uses no OS.
I think I missed something.
BTW, when this problem happens, TX IRQ routine function is not issued even CPSW_CPDMA interrupt status is set. It enters IRQ routine after I write TX HDP few more times.
Thanks a lot.

BR, Nathan

Hi Eric,
I used Hilscher's Ethernet Analyzer and I found that some frames were no caught by Wireshark. So I already found the cause of my problem.
It's not caused by CPSW.
Thanks.
Nathan