[PATCH]: Mux n_gsm: Add a DLCI hangup state and callback

[Gwenn Bourrée]

Dear kernel tty maintainers,
 
Please review the following patch:

From 6e006bd522124d0e8a2f6075099a21f7051a426f Mon Sep 17 00:00:00 2001
From: Gwenn Bourree <gwenn.bourree@xxxxxxxxx>
Date: Mon, 29 Jun 2015 17:26:01 +0200
Subject: [PATCH] Mux n_gsm: Add a DLCI hangup state and callback

Use of asynchronous hangup instead of vhangup.

Signed-off-by: Gwenn Bourree <gwenn.bourree@xxxxxxxxx>
Signed-off-by: Gwenn Bourree <gwenn.bourree@xxxxxxxxx>
Signed-off-by: Mustapha Ben Zoubeir <mustaphax.ben.zoubeir@xxxxxxxxx>
Signed-off-by: Nicolas LOUIS <nicolasx.louis@xxxxxxxxx>
Reviewed-by: Ravindran, Arun <arun.ravindran@xxxxxxxxx

---
 drivers/tty/n_gsm.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index d6e0ea0..762f555 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -135,6 +135,7 @@ struct gsm_dlci {
 #define DLCI_OPENING		1	/* Sending SABM not seen UA */
 #define DLCI_OPEN		2	/* SABM/UA complete */
 #define DLCI_CLOSING		3	/* Sending DISC not seen UA/DM */
+#define DLCI_HANGUP		4	/*HANGUP received  */
 	struct mutex mutex;
 
 	/* Link layer */
@@ -1530,7 +1531,8 @@ static void gsm_dlci_begin_open(struct gsm_dlci
*dlci)
 static void gsm_dlci_begin_close(struct gsm_dlci *dlci)
 {
 	struct gsm_mux *gsm = dlci->gsm;
-	if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING)
+	if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING ||
+		dlci->state == DLCI_HANGUP)
 		return;
 	dlci->retries = gsm->n2;
 	dlci->state = DLCI_CLOSING;
@@ -1717,7 +1719,7 @@ static void gsm_dlci_release(struct gsm_dlci
*dlci)
 		gsm_destroy_network(dlci);
 		mutex_unlock(&dlci->mutex);
 
-		tty_vhangup(tty);
+		tty_hangup(tty);
 
 		tty_port_tty_set(&dlci->port, NULL);
 		tty_kref_put(tty);
@@ -2339,6 +2341,26 @@ static void gsmld_flush_buffer(struct tty_struct
*tty)
 }
 
 /**
+ *	gsmld_hangup		-	hangup the ldisc for this tty
+ *	@tty: device
+ */
+
+static int gsmld_hangup(struct tty_struct *tty)
+{
+	struct gsm_mux *gsm = tty->disc_data;
+	int i;
+	struct gsm_dlci *dlci;
+
+	for (i = NUM_DLCI-1; i >= 0; i--) {
+		dlci = gsm->dlci[i];
+		if (dlci)
+			dlci->state = DLCI_HANGUP;
+	}
+
+	return 0;
+}
+
+/**
  *	gsmld_close		-	close the ldisc for this tty
  *	@tty: device
  *
@@ -2836,6 +2858,7 @@ static struct tty_ldisc_ops tty_ldisc_packet = {
 	.name            = "n_gsm",
 	.open            = gsmld_open,
 	.close           = gsmld_close,
+	.hangup          = gsmld_hangup,
 	.flush_buffer    = gsmld_flush_buffer,
 	.chars_in_buffer = gsmld_chars_in_buffer,
 	.read            = gsmld_read,


---------------------------------------------------------------------
Intel Corporation SAS (French simplified joint stock company)
Registered headquarters: "Les Montalets"- 2, rue de Paris, 
92196 Meudon Cedex, France
Registration Number:  302 456 199 R.C.S. NANTERRE
Capital: 4,572,000 Euros

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.
N‹§²æ¸›yú²X¬¶ÇvØ–)Þ{.nlj·¥Š{±‘êX§¶›¡Ü}©ž²ÆzÚj:+v‰¨¾«‘êZ+€Êzf£¢·hšˆ§~†­†Ûÿû®w¥¢¸?™¨è&¢)ßf”ùy§m…á«a¶Úÿ0¶ìå