diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index d31b975dd3fd..6b854237c788 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -472,6 +472,15 @@ static void dw8250_setup_port(struct uart_port *p)
 	}
 
 	reg = dw8250_readl_ext(p, DW_UART_CPR);
+
+#ifdef CONFIG_ARCH_ROCKCHIP
+	/*
+	 * The UART CPR may be 0 of some rockchip soc,
+	 * but it supports fifo and AFC, fifo entry is 32 default.
+	 */
+	if (reg == 0)
+		reg = 0x00023ff2;
+#endif
 	if (!reg)
 		return;
 
@@ -480,6 +489,9 @@ static void dw8250_setup_port(struct uart_port *p)
 		p->type = PORT_16550A;
 		p->flags |= UPF_FIXED_TYPE;
 		p->fifosize = DW_UART_CPR_FIFO_SIZE(reg);
+#ifdef CONFIG_ARCH_ROCKCHIP
+		up->tx_loadsz = p->fifosize * 3 / 4;
+#endif
 		up->capabilities = UART_CAP_FIFO;
 	}