From: 黄涛 <huangtao@rock-chips.com>
Date: Thu, 13 Jan 2011 08:50:50 +0000 (+0800)
Subject: serial: rk29: rk29_console_setup add clear rx fifo
X-Git-Tag: firefly_0821_release~10812
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=c158e9a5b00edc6abfbfeab31236e382ae59bbc0;p=firefly-linux-kernel-4.4.55.git

serial: rk29: rk29_console_setup add clear rx fifo
---

diff --git a/drivers/serial/rk29_serial.c b/drivers/serial/rk29_serial.c
index bd1fe6b515c7..8d896509cc7a 100755
--- a/drivers/serial/rk29_serial.c
+++ b/drivers/serial/rk29_serial.c
@@ -40,7 +40,7 @@
 #if 0
 #define DBG     printk
 #else
-#define DBG
+#define DBG(...)
 #endif
 /*
  * We wrap our port structure around the generic uart_port.
@@ -630,6 +630,10 @@ static int __init rk29_console_setup(struct console *co, char *options)
 
 	printk(KERN_INFO "rk29_serial: console setup on port %d\n", port->line);
 
+	/* clear rx fifo, else will blocked on set_termios (always busy) */
+	while ((rk29_uart_read(port, UART_USR) & UART_RECEIVE_FIFO_NOT_EMPTY) == UART_RECEIVE_FIFO_NOT_EMPTY)
+		rk29_uart_read(port, UART_RBR);
+
 	return uart_set_options(port, co, baud, parity, bits, flow);	
 }