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authorDavid Howells <dhowells@redhat.com>2008-12-03 16:33:14 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2008-12-03 16:47:40 -0800
commit004b50f4ed2accb56069d56714a32484f8b83ec0 (patch)
tree7b8a8960972fed8e2c7bff027eb039e7e2d8d7f6 /arch/mn10300/kernel/gdb-io-serial.c
parent8711cca2251f1fc3beb870a75ff847bb55225490 (diff)
downloadblackbird-op-linux-004b50f4ed2accb56069d56714a32484f8b83ec0.tar.gz
blackbird-op-linux-004b50f4ed2accb56069d56714a32484f8b83ec0.zip
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>
Diffstat (limited to 'arch/mn10300/kernel/gdb-io-serial.c')
-rw-r--r--arch/mn10300/kernel/gdb-io-serial.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/mn10300/kernel/gdb-io-serial.c b/arch/mn10300/kernel/gdb-io-serial.c
index 9a6d4e8ebe73..11584c51acd9 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) {
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