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Message-Id: <1236321780-28718-3-git-send-email-cooloney@kernel.org>
Date: Fri, 6 Mar 2009 14:42:44 +0800
From: Bryan Wu <cooloney@...nel.org>
To: alan@...rguk.ukuu.org.uk
Cc: linux-kernel@...r.kernel.org, Graf Yang <graf.yang@...log.com>,
Bryan Wu <cooloney@...nel.org>
Subject: [PATCH 02/18] Blackfin Serial Driver: use barrier instead of cpu_relax for Blackfin SMP like patch
From: Graf Yang <graf.yang@...log.com>
We are making a SMP like patch to blackfin, cpu_relax() is replaced by a
data cache flush function which will count it to a per-cpu counter.
If this serial function is called too early, the per-cpu data area have
not been initialized, this call will cause crash.
So we'd like to use barrier() instead of cpu_relax().
Signed-off-by: Graf Yang <graf.yang@...log.com>
Signed-off-by: Bryan Wu <cooloney@...nel.org>
---
drivers/serial/bfin_5xx.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index 52ccc27..350bfc4 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -1129,7 +1129,8 @@ static __init void early_serial_putc(struct uart_port *port, int ch)
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
while ((!(UART_GET_LSR(uart) & THRE)) && --timeout)
- cpu_relax();
+ barrier();
+
UART_PUT_CHAR(uart, ch);
}
--
1.5.6.3
--
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