From: xiaojin <jin.xiao@intel.com>
Date: Wed, 19 Dec 2012 03:53:43 +0000 (+0800)
Subject: n_gsm.c: add tx_lock in gsm_send
X-Git-Tag: firefly_0821_release~3680^2~1078^2~134
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f96f7f7f39af53274d98aa9c29d6fa4d122218a4;p=firefly-linux-kernel-4.4.55.git

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>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index dcc0430a49c8..4572117988f8 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);
 }