RCP Timeout and Crash Under High Command Load (Flooding) with Framing Errors

[Vvg1997]

Issue Description
When flooding control commands (e.g., repeated On/Off cluster commands) from the ChipTool APK to a Thread end device (Nanoleaf), the otbr-agent crashes due to an RCP timeout and framing errors in the RCP communication layer.

Tested with Below Configurations
Baud 115200 and 460800
NCP_TX_BUFFER - 1024 and 4096

Environment
OTBR - otbr-posix (OpenThread Border Router)
Repository: https://github.com/openthread/ot-br-posix.git
Branch: main
Commit: 6112f9802f32c41b15ble331bf391c2c0f86bbc5

RCP Hardware: NXP JN5189
RCP Firmware - Repository: https://github.com/openthread/ot-nxp.git
Branch: main
Commit: openthread/ot-nxp@70a5b2d

Host OS: Linux (OpenWRT)
Thread version: 1.4.0

Commissioner: ChipTool APK (Android)

End Device: Nanoleaf Thread Device

Reproduction Steps
Commission the Nanoleaf device onto the Thread network via OTBR.
Use ChipTool APK to send rapid commands (e.g., toggle command in a loop with minimal delay).
Observe otbr-agent logs for framing errors and eventual timeout crash.

I've  attached OTBR Agent Log and For Compilation Purpose I've applied the below patches on top of the vanilla ot-nxp repo

[luis_maravilla]

Hi,

Are you following an application note for doing the test?

I notice that you are using a different link for OpenThread,  Could you please try with this Github by NXP

https://github.com/NXP/ot-nxp/blob/release/v1.4.0/src/k32w0/jn5189/README.md

[Vvg1997]

Hi,

Thanks for pointing that out.

To clarify, I wasn’t following any specific application note for this test. The OpenThread repo I referenced is, to the best of my knowledge, the official OT-NXP repository. The one you've shared appears to be a user-forked version rather than the mainline maintained by NXP.

I did give the repo you linked a try.
1) However, when building with the SDK version specified in the README (SDK_6_3), I ran into build errors (find it in the attached log files). On the other hand, using SDK_6_16, I was able to successfully compile without issues.
2) There's no such folder as "mr3_fixes" inside "third_party/jn5189_sdk" as specified in the README file for applying patch (patch_jn5189_mr3_sdk.sh). I proceeded with the build without applying them

After building successfully i flashed the RCP binary and once again tried to test, But still facing the same issue. 

[luis_maravilla]

Hi

NXP is currently migrating information to update the Open Thread GitHub repository. Both repositories are official NXP repositories. The one I shared will be the primary github for future support by NXP as will get more updates later.

I would recommend checking on NXP examples for Open Thread Border Router for future I.MX reference

GitHub - nxp-imx/meta-nxp-connectivity at imx_matter_2024_q4

Best Regards