TM4C1294NCPDT: The UART RX interrupt can't be triggered

I have an EK-TM4C129XL that is to be control from Matlab on PC over serial/UART.

The problem is that the transmissions from PC do not trigger the receive interrupt. I do not forget to "resume" before trying.

Please check if I correctly configure everything. Here is the relevant code.

void initPCInterface(uint32_t sys_clk)
{

    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
    GPIOPinConfigure(GPIO_PA0_U0RX);
    GPIOPinConfigure(GPIO_PA1_U0TX);
    GPIOPinTypeUART(GPIO_PORTA_BASE, 0b00000011);
    UARTConfigSetExpClk(UART0_BASE, sys_clk, 57600, 
                        (UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
                                UART_CONFIG_PAR_NONE));
    UARTFIFOEnable(UART0_BASE);
    UARTFIFOLevelSet(UART0_BASE,UART_FIFO_TX2_8, UART_FIFO_RX2_8);
    UARTIntEnable(UART0_BASE, UART_INT_RX);
    UARTIntRegister(UART0_BASE, pcCommInterface);
    IntPrioritySet(INT_UART0,0x20);//MEDIUM PRIORITY
    IntEnable(INT_UART0);
}

void initGPIO(void)
{
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOB));
    GPIOPinTypeGPIOOutput(GPIO_PORTB_BASE, PB_MASK);
    GPIOPinWrite(GPIO_PORTB_BASE, PB_MASK,0);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOP);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOP));
    GPIOPinTypeGPIOOutput(GPIO_PORTP_BASE, PP_MASK);
    GPIOPinWrite(GPIO_PORTP_BASE, PP_MASK,0);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOE));
    GPIOPinTypeGPIOOutput(GPIO_PORTE_BASE, PE_MASK);
    GPIOPinWrite(GPIO_PORTE_BASE, PE_MASK,0);


    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOC));
    GPIOPinTypeGPIOOutput(GPIO_PORTC_BASE, PC_MASK);
    GPIOPinWrite(GPIO_PORTC_BASE, PC_MASK,0);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOQ);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOQ));
    GPIOPinTypeGPIOOutput(GPIO_PORTQ_BASE, PQ_MASK);
    GPIOPinWrite(GPIO_PORTQ_BASE, PQ_MASK,0);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOK);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOK));
    GPIOPinTypeGPIOInput(GPIO_PORTK_BASE, PK_MASK);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOD));
    //Unlock PD7, default NMI
     HWREG(GPIO_PORTD_BASE + GPIO_O_LOCK) = GPIO_LOCK_KEY;
     HWREG(GPIO_PORTD_BASE + GPIO_O_CR) = 0x80;
    GPIOPinTypeGPIOInput(GPIO_PORTD_BASE, PD_MASK);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOM); 
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOM));
    GPIOPinTypeGPIOInput(GPIO_PORTM_BASE, PM_MASK);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);
        while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPION));
        GPIOPinTypeGPIOInput(GPIO_PORTN_BASE, PN_MASK);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOA));
    GPIOPinTypeGPIOInput(GPIO_PORTA_BASE, PA_MASK);
}

int main(void)
{
    {// limit scope of sys_clock
    uint32_t sys_clock = SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
                     SYSCTL_OSC_MAIN | SYSCTL_USE_PLL |
                     SYSCTL_CFG_VCO_480), 120000000);
    initGPIO();
    initPCInterface(sys_clock);
    }//sys_clock is popped from stack
    IntMasterEnable();

	while(true);
}

minimal Matlab test. Matlab successfully opens the port

clear
close all
s=serial('/dev/ttyS0',...
    'BaudRate', 57600,'DataBits', 8,'Parity', 'none', ...
    'StopBits',1, 'Timeout',2);

fopen(s);%successful
fprintf(s, 'rzzzzzklkll');%send something, does nothing
fclose(s);