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>
This commit is contained in:
David Howells 2008-12-03 16:33:14 +00:00 коммит произвёл Linus Torvalds
Родитель 8711cca225
Коммит 004b50f4ed
1 изменённых файлов: 2 добавлений и 0 удалений

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@ -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) {