NUC980 串口设置1200及以下波特率时无法设置成功

内核版本：
使用的就是github上最新的内核

在内核驱动代码nuc980_serial.c文件里的nuc980serial_set_termios函数里加入一条打印信息:

static void
nuc980serial_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old)
{
    struct uart_nuc980_port *up = (struct uart_nuc980_port *)port;
    unsigned int lcr = 0;
    unsigned long flags;
    unsigned int baud, quot;

    switch (termios->c_cflag & CSIZE) {
    case CS5:
        lcr = 0;
        break;
    case CS6:
        lcr |= 1;
        break;
    case CS7:
        lcr |= 2;
        break;
    default:
    case CS8:
        lcr |= 3;
        break;
    }

    if (termios->c_cflag & CSTOPB)
        lcr |= NSB;
    if (termios->c_cflag & PARENB)
        lcr |= PBE;
    if (!(termios->c_cflag & PARODD))
        lcr |= EPE;
    if (termios->c_cflag & CMSPAR)
        lcr |= SPE;

    baud = uart_get_baud_rate(port, termios, old, port->uartclk / 0xffff, port->uartclk / 11);
    quot = nuc980serial_get_divisor(port, baud);
    printk("in nuc980serial_set_termios, quot = %d, baud = %d \n", quot, baud); //增加这一条打印信息
    /*
     * Ok, we're now changing the port state.  Do it with
     * interrupts disabled.
     */
    spin_lock_irqsave(&up->port.lock, flags);

    up->port.read_status_mask = RX_OVER_IF /*| UART_LSR_THRE | UART_LSR_DR*/;
    if (termios->c_iflag & INPCK)
        up->port.read_status_mask |= FEF | PEF;
    if (termios->c_iflag & (BRKINT | PARMRK))
        up->port.read_status_mask |= BIF;

    /*
     * Characteres to ignore
     */
    up->port.ignore_status_mask = 0;
    if (termios->c_iflag & IGNPAR)
        up->port.ignore_status_mask |= FEF | PEF;
    if (termios->c_iflag & IGNBRK) {
        up->port.ignore_status_mask |= BIF;
        /*
         * If we're ignoring parity and break indicators,
         * ignore overruns too (for real raw support).
         */
        if (termios->c_iflag & IGNPAR)
            up->port.ignore_status_mask |= RX_OVER_IF;
    }

    if (termios->c_cflag & CRTSCTS)
        up->mcr |= UART_MCR_AFE;
    else
        up->mcr &= ~UART_MCR_AFE;

    nuc980serial_set_mctrl(&up->port, up->port.mctrl);

    serial_out(up, UART_REG_BAUD, quot | 0x30000000);

    serial_out(up, UART_REG_LCR, lcr);

    spin_unlock_irqrestore(&up->port.lock, flags);


}

然后重新编译内核，下载重启后，通过应用程序设置波特率，设置1200波特率及以下波特率时，

这个打印的波特率就一直是9600

请问这个问题应该如何解决？

谢谢！

检查下uartclk 是否设置成功