The problem is not FreeRTOS but buggy and ugly STM32 netif driver. I have
studied original driver provided by ST and had nothing but rewrite it.
Just one example of wrong architecture of this driver. This is from
low_level_output():
buffer = (u8 *)(DMATxDescToSet->Buffer1Addr);
for(q = p; q != NULL; q = q->next)
{
memcpy((u8_t*)&buffer[l], q->payload, q->len);
l = l + q->len;
}
Consider that buffers are allocated as
extern uint8_t Tx_Buff[ETH_TXBUFNB][ETH_TX_BUF_SIZE];
and are linked to chained DMA descriptors.
If packet size bigger then ETH_TX_BUF_SIZE you are at potential danger of
wrap around that is not treated in code. Same happens for RX flow. So no
surprise you have a problems with big packets.
And this is only one place, there is a number of others. There are also a
few races.
In short DO NOT USE THIS DRIVER.
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