1 files changed, 51 insertions, 13 deletions

diff --git a/drivers/tty/hvc/hvc_iucv.c b/drivers/tty/hvc/hvc_iucv.c
index 9d47f50c2755..fd17a9b804b8 100644
--- a/drivers/tty/hvc/hvc_iucv.c
+++ b/drivers/tty/hvc/hvc_iucv.c
@@ -656,21 +656,64 @@ static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
 }
 
 /**
+ * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS
+ * @hp:         Pointer the HVC device (struct hvc_struct)
+ * @raise:      Non-zero to raise or zero to lower DTR/RTS lines
+ *
+ * This routine notifies the HVC back-end to raise or lower DTR/RTS
+ * lines.  Raising DTR/RTS is ignored.  Lowering DTR/RTS indicates to
+ * drop the IUCV connection (similar to hang up the modem).
+ */
+static void hvc_iucv_dtr_rts(struct hvc_struct *hp, int raise)
+{
+        struct hvc_iucv_private *priv;
+        struct iucv_path        *path;
+
+        /* Raising the DTR/RTS is ignored as IUCV connections can be
+         * established at any times.
+         */
+        if (raise)
+                return;
+
+        priv = hvc_iucv_get_private(hp->vtermno);
+        if (!priv)
+                return;
+
+        /* Lowering the DTR/RTS lines disconnects an established IUCV
+         * connection.
+         */
+        flush_sndbuf_sync(priv);
+
+        spin_lock_bh(&priv->lock);
+        path = priv->path;              /* save reference to IUCV path */
+        priv->path = NULL;
+        priv->iucv_state = IUCV_DISCONN;
+        spin_unlock_bh(&priv->lock);
+
+        /* Sever IUCV path outside of priv->lock due to lock ordering of:
+         * priv->lock <--> iucv_table_lock */
+        if (path) {
+                iucv_path_sever(path, NULL);
+                iucv_path_free(path);
+        }
+}
+
+/**
  * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.
  * @hp:         Pointer to the HVC device (struct hvc_struct)
  * @id:         Additional data (originally passed to hvc_alloc):
  *              the index of an struct hvc_iucv_private instance.
  *
  * This routine notifies the HVC back-end that the last tty device fd has been
- * closed.  The function calls hvc_iucv_cleanup() to clean up the struct
- * hvc_iucv_private instance.
+ * closed.  The function cleans up tty resources.  The clean-up of the IUCV
+ * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios
+ * control setting.
  *
  * Locking:     struct hvc_iucv_private->lock
  */
 static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
 {
         struct hvc_iucv_private *priv;
-        struct iucv_path        *path;
 
         priv = hvc_iucv_get_private(id);
         if (!priv)
@@ -679,17 +722,11 @@ static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
         flush_sndbuf_sync(priv);
 
         spin_lock_bh(&priv->lock);
-        path = priv->path;              /* save reference to IUCV path */
-        priv->path = NULL;
-        hvc_iucv_cleanup(priv);
+        destroy_tty_buffer_list(&priv->tty_outqueue);
+        destroy_tty_buffer_list(&priv->tty_inqueue);
+        priv->tty_state = TTY_CLOSED;
+        priv->sndbuf_len = 0;
         spin_unlock_bh(&priv->lock);
-
-        /* sever IUCV path outside of priv->lock due to lock ordering of:
-         * priv->lock <--> iucv_table_lock */
-        if (path) {
-                iucv_path_sever(path, NULL);
-                iucv_path_free(path);
-        }
 }
 
 /**
@@ -931,6 +968,7 @@ static const struct hv_ops hvc_iucv_ops = {
         .notifier_add = hvc_iucv_notifier_add,
         .notifier_del = hvc_iucv_notifier_del,
         .notifier_hangup = hvc_iucv_notifier_hangup,
+        .dtr_rts = hvc_iucv_dtr_rts,
 };
 
 /* Suspend / resume device operations */