CC3200-LAUNCHXL: Can't read file from flash after hibernate system

/*File opertation variables*/
unsigned char readbuffer[BUF_SIZE];
SlFsFileInfo_t FileInfo;
long lFileHandle;
unsigned long ulToken;


/*Write file into flash*/
long WriteFileToDevice(unsigned long *ulToken, long *lFileHandle)
{
    long lRetVal = -1;

    //
    //  open a user file for writing
    //
    lRetVal = sl_FsOpen((unsigned char *)USER_FILE_NAME,
                        FS_MODE_OPEN_WRITE, 
                        ulToken,
                        lFileHandle);
	
    if(lRetVal < 0)
    {
        lRetVal = sl_FsClose(*lFileHandle, 0, 0, 0);
		return FAILURE;
    }
	
	lRetVal = sl_FsGetInfo(USER_FILE_NAME, 0, &FileInfo);
	if(lRetVal < 0)
    {
        GPIO_IF_LedOn(MCU_RED_LED_GPIO);
        LOOP_FOREVER();
    }
	UART_PRINT("Get file information:\n");
	UART_PRINT("FileLen: [%d]\n", FileInfo.FileLen);
	UART_PRINT("AllocatedLen: [%d]\n", FileInfo.AllocatedLen);
	UART_PRINT("File token: [%d]\n", FileInfo.Token);
	UART_PRINT("File flags: [%d]\n", FileInfo.flags);
	

	char ssid_name[] = "Lex_Hsiao";
	char *writebuffer=(char*)malloc(1024);
  memset(writebuffer,'\0',sizeof(writebuffer));
	memcpy(writebuffer, (char*)ssid_name, sizeof(ssid_name)-1);
    //
    // write new ssid, password and secure type into file
    //
    lRetVal = sl_FsWrite(*lFileHandle, 0, (unsigned char *)writebuffer, sizeof(ssid_name)-1);
    if (lRetVal < 0)
    {
        lRetVal = sl_FsClose(*lFileHandle, 0, 0, 0);
				return FAILURE;
    }
    
    //
    // close the user file
    //
    lRetVal = sl_FsClose(*lFileHandle, 0, 0, 0);
		UART_PRINT("Write file success\n\n");
    return SUCCESS;
}




/*Read file from flash*/
long ReadFileFromDevice(unsigned long ulToken, long lFileHandle)
{
    long lRetVal = -1;
	
    //
    // open a user file for reading
    //
    lRetVal = sl_FsOpen((unsigned char *)USER_FILE_NAME,
                        FS_MODE_OPEN_READ,
                        &ulToken,
                        &lFileHandle);

	if(lRetVal < 0)
	{
	  	lRetVal = sl_FsClose(lFileHandle, 0, 0, 0);
	  	return FAILURE;
	}

	//
  // read the data, lRetVal returns the number of read bytes
  //
  lRetVal = sl_FsRead(lFileHandle, 0, readbuffer, sizeof(readbuffer));
	UART_PRINT("Readbuffer length: %d\n", lRetVal);
	
    if(lRetVal < 0) 
	{
	  	UART_PRINT("Use default wifi setting.\n");
        lRetVal = sl_FsClose(lFileHandle, 0, 0, 0);
		return SUCCESS;
	}
	
	else
	{
		for (int i = 0; i < lRetVal; i++)
			UART_PRINT("%c", readbuffer[i]);
		UART_PRINT("\n");
		//
    // close the user file
    //
    lRetVal = sl_FsClose(lFileHandle, 0, 0, 0);

    return SUCCESS;
	}   
}


/*File operation*/
void FileOperation(void)
{
  	long lRetVal;

  	lRetVal = sl_Start(NULL, NULL, NULL);
    if(lRetVal < 0)
    {
        GPIO_IF_LedOn(MCU_RED_LED_GPIO);
        LOOP_FOREVER();
    }

	  //
    //  create a user file
    //
    lRetVal = sl_FsOpen((unsigned char *)USER_FILE_NAME,
                FS_MODE_OPEN_CREATE(65536, 
                          _FS_FILE_OPEN_FLAG_COMMIT|_FS_FILE_PUBLIC_WRITE|_FS_FILE_PUBLIC_READ),
                        &ulToken,
                        &lFileHandle);
	
    if(lRetVal < 0)
    {
	  	UART_PRINT("File %s already exist.\n", USER_FILE_NAME);
        //
        // File may already be created
        //
        lRetVal = sl_FsClose(lFileHandle, 0, 0, 0);
    }
    else
    {
        //
        // close the user file
        //
        lRetVal = sl_FsClose(lFileHandle, 0, 0, 0);
    }
	
	lRetVal = sl_FsGetInfo(USER_FILE_NAME, 0, &FileInfo);
	if(lRetVal < 0)
    {
        GPIO_IF_LedOn(MCU_RED_LED_GPIO);
        LOOP_FOREVER();
    }
	UART_PRINT("Get file information:\n");
	UART_PRINT("FileLen: [%d]\n", FileInfo.FileLen);
	UART_PRINT("AllocatedLen: [%d]\n", FileInfo.AllocatedLen);
	UART_PRINT("File token: [%d]\n", FileInfo.Token);
	UART_PRINT("File flags: [%d]\n", FileInfo.flags);
	
	if(ReadFileFromDevice(ulToken, lFileHandle) < 0)
    {
      GPIO_IF_LedOn(MCU_RED_LED_GPIO);
			UART_PRINT("Read file fail\n\n");
    }
	
	//lRetVal = sl_Stop(SL_STOP_TIMEOUT);
}


/*Push button interrupt handler*/
void pushButtonInterruptHandler2()
{	
  event_msg msg;
	msg.event = PUSH_BUTTON_SW2_PRESSED;
  msg.hndl = NULL;
  //
  // write message indicating exit from sending loop
  //
  osi_MsgQWrite(&g_PBQueue,&msg,OSI_NO_WAIT);
	
	Button_IF_EnableInterrupt(SW2);
}

/*Task for setting wifi direct information flag*/
void WifiDirectFlagSetting(void *pvParameters)
{
	event_msg RecvQue;
	
	for(;;)
	{
		osi_MsgQRead( &g_PBQueue, &RecvQue, OSI_WAIT_FOREVER);
		
		if(PUSH_BUTTON_SW2_PRESSED == RecvQue.event)
		{
			if(WriteFileToDevice(&ulToken, &lFileHandle) < 0)
    		{
        	GPIO_IF_LedOn(MCU_RED_LED_GPIO);
					LOOP_FOREVER();	
    		}
			
			// Restart system
			MAP_PRCMHibernateIntervalSet(330);
			MAP_PRCMHibernateWakeupSourceEnable(PRCM_HIB_SLOW_CLK_CTR);
			MAP_PRCMHibernateEnter();
		}
	}
}

/*MqttClient task*/
void MqttClient(void *pvParameters)
{
	FileOperation();
}