A UART question related to character READ

Try this:

int uart_read(int base, char *ptr, int len, int flags){
    int block;
    unsigned int status;
    block = 1;//!(flags & O_NONBLOCK);
    do{
        status = IORD_ALTERA_AVALON_UART_STATUS(base);
        /* clear any error flags */
        IOWR_ALTERA_AVALON_UART_STATUS(base, 0);
        if (status & ALTERA_AVALON_UART_CONTROL_RRDY_MSK){
            ptr = IORD_ALTERA_AVALON_UART_RXDATA(base);
            if (!(status & (ALTERA_AVALON_UART_STATUS_PE_MSK | 
                ALTERA_AVALON_UART_STATUS_FE_MSK))){
                return 1;
            }
        }
    }while (block);
    return 0;
}