[PATCH] n_gsm.c: add tx_lock in gsm_send

From: Xiao Jin
Date: Thu Dec 20 2012 - 01:41:52 EST


From: xiaojin <jin.xiao@xxxxxxxxx>
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@xxxxxxxxx>
---
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



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