From a4ed06ad83acc3b7dafc018bc0b27469e787e27d Mon Sep 17 00:00:00 2001
From: Lennert Buytenhek <buytenh@wantstofly.org>
Date: Wed, 6 Dec 2006 20:39:57 -0800
Subject: [PATCH] [PATCH] amba-pl010: clear error flags on rx error
The pl010 primecell documentation specifies that an error indicated via RSR
should be cleared by a write to ECR. We didn't do this, which was causing
errors to be re-reported on every call to pl010_rx_chars().
Doing a write to ECR once we detect an error appears to prevent the ep93xx
console UART driver from going into a mode where it reports "ttyAM0: X
input overrun(s)" every couple of keystrokes.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
drivers/serial/amba-pl010.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/serial/amba-pl010.c b/drivers/serial/amba-pl010.c
index 4213fabc62bf..4d3626ef4643 100644
--- a/drivers/serial/amba-pl010.c
+++ b/drivers/serial/amba-pl010.c
@@ -129,6 +129,8 @@ static void pl010_rx_chars(struct uart_port *port)
*/
rsr = readb(port->membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
if (unlikely(rsr & UART01x_RSR_ANY)) {
+ writel(0, port->membase + UART01x_ECR);
+
if (rsr & UART01x_RSR_BE) {
rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
port->icount.brk++;