Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux...

[firefly-linux-kernel-4.4.55.git] / drivers / tty / hvc / hvc_iucv.c

diff --git a/drivers/tty/hvc/hvc_iucv.c b/drivers/tty/hvc/hvc_iucv.c
index 9d47f50c2755a37835ec04662a194db631dba08a..db19a38c8c69b0d33dddac2c1fff95f3f79b80f3 100644 (file)
--- a/drivers/tty/hvc/hvc_iucv.c
+++ b/drivers/tty/hvc/hvc_iucv.c
@@ -655,6 +655,49 @@ static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
        spin_unlock_bh(&priv->lock);
 }
 
+/**
+ * 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)
@@ -662,15 +705,15 @@ static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
  *             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 */
@@ -1316,8 +1354,7 @@ out_error_memory:
        mempool_destroy(hvc_iucv_mempool);
        kmem_cache_destroy(hvc_iucv_buffer_cache);
 out_error:
-       if (hvc_iucv_filter)
-               kfree(hvc_iucv_filter);
+       kfree(hvc_iucv_filter);
        hvc_iucv_devices = 0; /* ensure that we do not provide any device */
        return rc;
 }