[PATCH] n_gsm.c: add tx_lock in gsm_send

[Xiao Jin <jin.xiao@intel.com>]

From: xiaojin <jin.xiao@intel.com>
Date: Wed, 19 Dec 2012 11:53:43 +0800
Subject: [PATCH] n_gsm.c: add tx_lock in gsm_send

All the call to gsm->output should be in the tx_lock,
that could avoid potential race from MUX level. But
we have no tx_lock in gsm_send.

This patch is to add tx_lock in gsm_send.

Signed-off-by: xiaojin <jin.xiao@intel.com>
---
 drivers/tty/n_gsm.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index dcc0430..4572117 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -573,6 +573,7 @@ static void gsm_send(struct gsm_mux *gsm, int addr,
int cr, int control)
 	int len;
 	u8 cbuf[10];
 	u8 ibuf[3];
+	unsigned long flags;
 
 	switch (gsm->encoding) {
 	case 0:
@@ -602,7 +603,9 @@ static void gsm_send(struct gsm_mux *gsm, int addr,
int cr, int control)
 		WARN_ON(1);
 		return;
 	}
+	spin_lock_irqsave(&gsm->tx_lock, flags);
 	gsm->output(gsm, cbuf, len);
+	spin_unlock_irqrestore(&gsm->tx_lock, flags);
 	gsm_print_packet("-->", addr, cr, control, NULL, 0);
 }
 
-- 
1.7.1