MAX3421 as host: lost EP Rx transfer, race condition

[IngHK]

Board

NUCLEO-WL55JC1 (STM32WL55 with LoRaWAN, but no internal USB controller), external MAX3421 as host

Firmware

own firmware running on STM32 based on STM32CubeWL Firmware Package v1.3.0

What happened ?

I've maybe found a bug, but I'm not sure...
My application: STM32 with MAX3421 and TinyUSB host communicating with attached CDC device (RS232)
The issue: CDC Tx bulk transfers are lost depending on timing relationship of Rx/Tx bulk tranfers

I analysed the USB endpoint traffic with USB sniffer hardware (https://www.bugblat.com/products/minisniff/), inserted between MAX3421 and CDC device, and I see the the Rx EP transfers, but tuh_cdc_rx_cb is not everytime called.
It seems the failure appearance depending on the Rx/Tx timing relationship.

Is there still development in progress regarding MAX3421?
What can I test or what do I have to care or check about my setup STM32WL and MAX3421?

How to reproduce ?

My current HW/SW setup is quite special...
I'll try to create an easy reproducible constellation without special hardware in the next days.
You can request any measurements you want to have from me.
I've logic analyzer, oscilloscope and USB sniffer hardware in my lab.

Debug Log as txt file (LOG/CFG_TUSB_DEBUG=2)

There are no debug outputs, because the Rx EP transfer are lost as never happened.

Screenshots

No response

I have checked existing issues, dicussion and documentation

• I confirm I have checked existing issues, dicussion and documentation.