DCache is not cleared in ethernetif low_level_output function

[MWKIN]

Hi,

I'm using a STM32f767ZIT with FreeRTOS and LWIP on a custom board.
After running into some weird UDP transmission issues, I discoverd that in the generated ethernetif.c file, the DCache is not cleaned in the low_level_output function.

Adding this at line 414 ( after Txbuffer[i].len = q->len; ) in low_level_output() fixed my issues.

SCB_CleanDCache_by_Addr(
    (uint32_t *)((uint32_t)(Txbuffer[i].buffer) & ~0x1F),
    Txbuffer[i].len + ((uint32_t)(Txbuffer[i].buffer) & 0x1F)
);

In the HAL_ETH_RxLinkCallback, the SCB_InvalidateDCache_by_Addr is used, so this seems like an oversight?

[STackPointer64]

Hello @MWKIN, and welcome to the community!

Could you please provide more details about the UDP transmission issue? For example, are packets being dropped, is the dropping random, or are there CRC calculation errors? If possible, sharing a minimal project that reproduces the issue would be very helpful for analysis.

Best regards,