MSP432P401R: UART Interrupt Problem

char        input;
const char  echoPrompt[] = "Echoing characters:\r\n";
UART_Handle uart;
UART_Params uartParams;
int UART_DATA = 0;

void ReadCallBack(UART_Handle handle, void *buf, size_t count)
{
    UART_read(uart, &input, 1);
    UART_write(uart, &input, 1);
    UART_DATA = 1;
//    return;
}

/*
 *  ======== mainThread ========
 */
void *UART_Thread(void *arg0)
{
    //    char        input;
    //    const char  echoPrompt[] = "Echoing characters:\r\n";
    //    UART_Handle uart;
    //    UART_Params uartParams;

    /* Call driver init functions */
    GPIO_init();
    UART_init();

    /* Configure the LED pin */
    GPIO_setConfig(CONFIG_GPIO_0, GPIO_CFG_OUT_STD | GPIO_CFG_OUT_LOW);

    /* Turn on user LED */
    GPIO_write(CONFIG_GPIO_0, CONFIG_GPIO_LED_ON);

    /* Create a UART with data processing off. */
    UART_Params_init(&uartParams);
    uartParams.writeDataMode = UART_DATA_BINARY;
    uartParams.readDataMode = UART_DATA_TEXT;
    uartParams.readReturnMode = UART_RETURN_NEWLINE;
    uartParams.readEcho = UART_ECHO_OFF;
//    uartParams.readCallback = ReadCallBack;
//    uartParams.readMode = UART_MODE_CALLBACK;
    uartParams.baudRate = 115200;

    uart = UART_open(CONFIG_UART_0, &uartParams);

    if (uart == NULL) {
        /* UART_open() failed */
        while (1);
    }

    UART_write(uart, echoPrompt, sizeof(echoPrompt));
//    UART_read(uart, &input, 1);
    /* Loop forever echoing */
    while (1) {
        //        UART_read(uart, &input, 1);
//        if(UART_DATA)
//        {
//            UART_DATA = 0;
////            UART_write(uart, &input, 1);
////            GPIO_toggle(CONFIG_GPIO_0);
//        }
        UART_read(uart, &input, 1);
        UART_write(uart, &input, 1);
    }


    //    return 0;
}