[PATCH] tty: n_gsm: delete SABM command frame as requester

[Zhenguo Zhao <zhenguo6858@gmail.com>]

From: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com>

as initiator,it need to send SABM conmmand ,as requester,there is
no need to send the SABM control frame,it will cause redundant data.

Signed-off-by: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com>
---
 drivers/tty/n_gsm.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 5fea02c..e66418b 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -3005,8 +3005,9 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp)
 	/* We could in theory open and close before we wait - eg if we get
 	   a DM straight back. This is ok as that will have caused a hangup */
 	tty_port_set_initialized(port, 1);
-	/* Start sending off SABM messages */
-	gsm_dlci_begin_open(dlci);
+	/* Start sending off SABM messages for initiator */
+	if (gsm->initiator)
+		gsm_dlci_begin_open(dlci);
 	/* And wait for virtual carrier */
 	return tty_port_block_til_ready(port, tty, filp);
 }
-- 
1.9.1