(HAL_ETH_Transmit_IT(&heth, &TxConfig) == HAL_OK) { while(osSemaphoreAcquire(TxPktSemaphore, TIME_WAITING_FOR_INPUT)!=osOK)

{
}

HAL_ETH_ReleaseTxPacket(&heth);

} else { pbuf_free(p); } it wait indefinitely on configASSERT( pxQueue->uxItemSize == 0 );? Behaviour is unpredictable. do not know when this problem comes.