TM4C123GH6PM: SPI loopback mode send/receive data

Part Number: TM4C123GH6PM

I am using Tiva C launchpad and trying to use SPI in loopback mode. But I am confused on send and receive. I thought the data kept in SPI data register(DR) can be read by just reading DR, in

SPI_transfer func, when I check to transmit FIFO status it always read as "not empty". Why transmit FIFO is not getting clear.  Can anyone check my implementation, 

void SPIpin_Init (void)
{
	volatile unsigned long delay;
	SYSCTL_RCGCSSI_R |= 0x02;     		// 1) activate clock for SSI1
	delay =SYSCTL_RCGCSSI_R;
	
	SYSCTL_RCGC2_R |= 0x02;           // activate clock for Port B
  delay = SYSCTL_RCGC2_R;
	
	GPIO_PORTB_PCTL_R = 0x22220000;
	GPIO_PORTB_AFSEL_R|= 0x3C;
}


void SPIconf_Init (void)
{
	SSI1_CR1_R &=~ 0x02;											// SSI Disable, configuration mode
	SSI1_CR0_R|=(SPO_EN|SCR|SixteenBitSize);  //SPO=1 and SPH=0, Freescale , 16 bit size
	SSI1_CR1_R |= 0x05;												//Master | Loopback enable
	SSI1_CC_R|=0x0;				
	SSI1_CR1_R|= 0x02;												//Enable SPI
}


int SPI_transfer(int data)
{
	int receive=0;
	
	//Send data
		SSI1_DR_R = data;
	while((SSI1_SR_R & 0x01) ==0 )   // wait till Transmit FIFO is empty
	{
		
	}
	
	
	//Receive
	while(SSI1_SR_R & 0x04)  //Wait till Receive FIFO is empty
	{

		receive = SSI1_DR_R;
	}
	
	return receive;
}

int main(void){
	int val=0x3333;
	int rec=0;
	
	SPIpin_Init();              // initialize PA2 and make it output
	SPIconf_Init();
	while(1)
	{
		rec=SPI_transfer(val);   
		val++;
	}
}