Re: [lwip-users] TCP packet out-of-order

[Xun Chen]

I also try to identify if it was a resend, so I added a counter to the payload, but I haven't caught one fail since the modification last Friday, because WireShark quit when this happened over the weekend. Hopefully I can catch it soon

I am not using DMA and this one running on TI's TiVa

The main loop simply wait for the PC to instruct it to start, then it send out the first packet, and the following packets are all sent out in callback


On 10/31/2016 9:37 AM, address@hidden wrote:

Date: Mon, 31 Oct 2016 10:14:25 -0300
From: "Sergio R. Caprile" <address@hidden>
To: address@hidden
Subject: Re: [lwip-users] TCP packet out-of-order
Message-ID: <address@hidden>
Content-Type: text/plain; charset=utf-8; format=flowed

I see your out-of-order friend in frame #11 looks very much like frame 
#8 revisited. I would say that is a DMA driver glitch (are you using DMA 
?), however, the IP ID field is different, so it looks more like a 
resend, due to frame #9 being internally lost; however, this does not 
look consistent with frame #10. I see frame #10 is 700us after the ACK, 
while others are usually 200us after the ACK. We might have something 
here...

Maybe

>> you might be not paying attention to single-threading rules for
>> low-level functions and trashing your memory,
>> your application might be trashing memory.

your DMA driver is messing around,
or we found an elusive lwIP bug.

Can you please
  describe your driver,
  describe your main loop
  confirm you don't call lwIP from main loop and interrupts, single 
context only.
  post your lwipopts file,
  post how you are using the RAW API,
  and try with a simple known-good app like netio if you run into the 
same issue ?