Hello, I work with STM32F4 lwip1.4.0 and FreeRTOS 7.5.2. I currently have a crash or assert the LwIP after some time because the MEMP is corrupt. I found a way to avoid this is xHigherPriorityTaskWoken to NULL in the Ethernet interrupt:

void ETH_IRQHandler(void)
{
  portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

  /* Frame received */
  if ( ETH_GetDMAFlagStatus(ETH_DMA_FLAG_R) == SET) 
  {
    /* Give the semaphore to wakeup LwIP task */
    xSemaphoreGiveFromISR( s_xSemaphore, NULL );
  }

  /* Clear the interrupt flags. */
  /* Clear the Eth DMA Rx IT pending bits */
  ETH_DMAClearITPendingBit(ETH_DMA_IT_R);
  ETH_DMAClearITPendingBit(ETH_DMA_IT_NIS);

  /* Switch tasks if necessary. */  
  if( xHigherPriorityTaskWoken != pdFALSE )
  {
    portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
  }
}

Well I guess I have a problem when config interrupt. Here is my config (assert is enabled): NVIC_PriorityGroupConfig( NVIC_PriorityGroup_4 ); NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 15; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; // Enable the Ethernet global Interrupt * *NVIC_InitStructure.NVIC_IRQChannel = ETH_IRQn; NVIC_Init(&NVIC_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn; NVIC_Init(&NVIC_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = SDIO_IRQn; NVIC_Init(&NVIC_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = SD_SDIO_DMA_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; NVIC_Init(&NVIC_InitStructure); I set priorities for SD_DMA except it does not work if I put 15. I will check the reason. Did I make a mistake? Note: At this time SD is only used at startup before scheduler runs. When scheduler is started only tick and Ethernet interrupt are running. It means there is a nested interrupt between tick and Ethernet? Pierre

The code is designed to nest, so that should not be a problem, provided your configuration is correct. It appears your NVIC interrupt priority is set to be the lowest value, so that should be fine. Assuming the interrupts that are enabled before the scheduler starts are not trying to use the scheduler it might be that your problem lies elsewhere. Regards.

Thanks Richard. I’m hard to see why if I put 15 for SDSDIODMAIRQn Priority I no longer interrupt SDIO / SDIODMA. I put 15: -If I made ​​no calls to the configuration of queues etc and I don’t create task the interrupt occurs (in fact only vTaskStartScheduler is called but it has nothing to do). -If I do as above, but I enabled FATFS with FSREENTRANT, it will create a mutex to access disk and I will not have to interrupt either. I hope this is clear. I must say that I do not see the connection between FreeRTOS and which interrupts are disabled. But important remark: In the last point One call to mutex by xSemaphoreTake is done before the scheduler runs (and it returns pdTRUE). I don’t know if it is a problem? Pierre

I changed the startup code: int main(void) { xTaskCreate(Maintask, (const signed portCHAR *)”MAIN”, configMINIMALSTACK_SIZE*4, NULL, 1, NULL); vTaskStartScheduler(); } Maintask is my previous main without vTaskStartScheduler();, and Maintask deletes itself the task. Now all access to os stuff are done with the scheduler running. It seems working with the SD priority to 15. I’ll let it run… KR, Pierre