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Wi-Fi Combo

BeOl_4470266
New Contributor II

Hello,

When could we expect support for the LwIP Chained Buffers?

At the moment, Wiced does not properly support LwIP without this. The Chained Buffers are a core feature of LwIP which cannot be deactivated.

My previous post was closed as Solved but the issue itself is not: https://community.infineon.com/t5/Wi-Fi-Combo/low-level-output-asserting-with-quot-No-chained-buffer...

Thanks for your support,

Best regards

 

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8 Replies
Rakesh_BG
Moderator
Moderator

Hi @BeOl_4470266 ,

Can you share the example code which you are using when you faced the problem mentioned in previous post.

Thanks & Regards,

Rakesh B G

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BeOl_4470266
New Contributor II

Hi,

Thanks for your answer.

I don't have a practical subset of code to provide, but that should not be necessary anyway: the problem was clearly identified in the previous post on this subject.

When could we expect support for the LwIP Chained Buffers?

Thanks in advance for your support on this product,

Best regards

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AxLi_1746341
Honored Contributor

This is nothing to do with application code.
lwIP supports chained pbuf and you can not stop it to do that.
(A packet may span over multiple pbufs, chained as a singly linked list. This is called a "pbuf chain".)

So the driver *must* take care of chained pbuf.

RoHe_4370821
New Contributor II

Hi,


I too have a problem with this issue. The support for chained buffers is clearly missing and needs implemented. I see frequent TCP errors that I assume are as a result of this issue. I have attached a screenshot of the assertion that is hit in the debugger.

Regards,
Rob


image-2021-04-05-07-58-36-312.png

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Rakesh_BG
Moderator
Moderator

Hi @BeOl_4470266 ,

There is no plan to support lwIP buffer chaining in wiced. 

Regards,

Rakesh B G

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RoHe_4370821
New Contributor II

Dear Infineon Support,

This issue needs to be fixed, as it is causing your customers products to have networking issues. A solution  needs to be implemented.

Regards,
Rob

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AxLi_1746341
Honored Contributor

@Rakesh_BG 

I think 3 possible ways to address this bug.
1. Make WWD driver support chained pbuf
2. Hack lwIP to prevent chain pbuf
3. Convert chained pbuf into a single large pbuf before pass to WWD

You know people already hit this issue, the bug is real. This issue needs urgent fix.

AxLi_1746341
Honored Contributor

@RaktimR_11 @Rakesh_BG @AditiB_81 

The "No chained buffers" assertion is also reported here: (Jun 05, 2019)
https://community.infineon.com/t5/Wi-Fi-Combo/iperf-with-LWIP-FreeRTOS/m-p/169566
Why there is no fix for more than 2 *years*.