From 2003c94bc0090357dfaccdeaa6f77436e837a3e4 Mon Sep 17 00:00:00 2001
From: Huibin Hong <huibin.hong@rock-chips.com>
Date: Tue, 8 May 2018 15:46:30 +0800
Subject: [PATCH] serial: 8250: set fifo rx trigger 1/2 of fifo

To reduce the uart interrupts, which may cause:

serial8250: too much work for irq xx

Change-Id: I89e0d990677e4cffae431e60521b3e16e8381f05
Signed-off-by: Huibin Hong <huibin.hong@rock-chips.com>
---
 drivers/tty/serial/8250/8250_port.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 3f779d25ec0c..c4f491c41542 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2748,7 +2748,9 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 	}
 
 	serial8250_set_divisor(port, baud, quot, frac);
-
+#ifdef CONFIG_ARCH_ROCKCHIP
+	up->fcr = UART_FCR_ENABLE_FIFO | UART_FCR_T_TRIG_10 | UART_FCR_R_TRIG_10;
+#endif
 	/*
 	 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
 	 * is written without DLAB set, this mode will be disabled.