From 004b50f4ed2accb56069d56714a32484f8b83ec0 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Wed, 3 Dec 2008 16:33:14 +0000
Subject: [PATCH] MN10300: Introduce barriers to replace removed volatiles in
gdbstub 16550 driver
Introduce into the MN10300 gdbstub 16550 driver a couple of barrier() calls to
replace the removed volatility of the input/output index variables for the Rx
ring buffer. A previous patch added them into the on-chip serial port driver.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/mn10300/kernel/gdb-io-serial.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/mn10300/kernel/gdb-io-serial.c b/arch/mn10300/kernel/gdb-io-serial.c
index 9a6d4e8ebe7..11584c51acd 100644
--- a/arch/mn10300/kernel/gdb-io-serial.c
+++ b/arch/mn10300/kernel/gdb-io-serial.c
@@ -99,6 +99,7 @@ int gdbstub_io_rx_char(unsigned char *_ch, int nonblock)
try_again:
/* pull chars out of the buffer */
ix = gdbstub_rx_outp;
+ barrier();
if (ix == gdbstub_rx_inp) {
if (nonblock)
return -EAGAIN;
@@ -110,6 +111,7 @@ int gdbstub_io_rx_char(unsigned char *_ch, int nonblock)
ch = gdbstub_rx_buffer[ix++];
st = gdbstub_rx_buffer[ix++];
+ barrier();
gdbstub_rx_outp = ix & 0x00000fff;
if (st & UART_LSR_BI) {
--
2.41.3