3 files changed, 27 insertions, 15 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index ea18a129b0b5..59499ee0fe6a 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1389,7 +1389,7 @@ EXPORT_SYMBOL(tty_shutdown);
  *      of ttys that the driver keeps.
  *
  *      This method gets called from a work queue so that the driver private
- *      shutdown ops can sleep (needed for USB at least)
+ *      cleanup ops can sleep (needed for USB at least)
  */
 static void release_one_tty(struct work_struct *work)
 {
@@ -1397,10 +1397,9 @@ static void release_one_tty(struct work_struct *work)
                 container_of(work, struct tty_struct, hangup_work);
         struct tty_driver *driver = tty->driver;
 
-        if (tty->ops->shutdown)
-                tty->ops->shutdown(tty);
-        else
-                tty_shutdown(tty);
+        if (tty->ops->cleanup)
+                tty->ops->cleanup(tty);
+
         tty->magic = 0;
         tty_driver_kref_put(driver);
         module_put(driver->owner);
@@ -1415,6 +1414,12 @@ static void release_one_tty(struct work_struct *work)
 static void queue_release_one_tty(struct kref *kref)
 {
         struct tty_struct *tty = container_of(kref, struct tty_struct, kref);
+
+        if (tty->ops->shutdown)
+                tty->ops->shutdown(tty);
+        else
+                tty_shutdown(tty);
+
         /* The hangup queue is now free so we can reuse it rather than
            waste a chunk of memory for each port */
         INIT_WORK(&tty->hangup_work, release_one_tty);
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index ff75a3589e7e..aa6b2ae951ae 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -192,7 +192,7 @@ void usb_serial_put(struct usb_serial *serial)
  * This is the first place a new tty gets used.  Hence this is where we
  * acquire references to the usb_serial structure and the driver module,
  * where we store a pointer to the port, and where we do an autoresume.
- * All these actions are reversed in serial_release().
+ * All these actions are reversed in serial_cleanup().
  */
 static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
 {
@@ -339,15 +339,16 @@ static void serial_close(struct tty_struct *tty, struct file *filp)
 }
 
 /**
- * serial_release - free resources post close/hangup
+ * serial_cleanup - free resources post close/hangup
  * @port: port to free up
  *
  * Do the resource freeing and refcount dropping for the port.
  * Avoid freeing the console.
  *
- * Called when the last tty kref is dropped.
+ * Called asynchronously after the last tty kref is dropped,
+ * and the tty layer has already done the tty_shutdown(tty);
  */
-static void serial_release(struct tty_struct *tty)
+static void serial_cleanup(struct tty_struct *tty)
 {
         struct usb_serial_port *port = tty->driver_data;
         struct usb_serial *serial;
@@ -361,9 +362,6 @@ static void serial_release(struct tty_struct *tty)
 
         dbg("%s - port %d", __func__, port->number);
 
-        /* Standard shutdown processing */
-        tty_shutdown(tty);
-
         tty->driver_data = NULL;
 
         serial = port->serial;
@@ -1210,7 +1208,7 @@ static const struct tty_operations serial_ops = {
         .chars_in_buffer =      serial_chars_in_buffer,
         .tiocmget =             serial_tiocmget,
         .tiocmset =             serial_tiocmset,
-        .shutdown =             serial_release,
+        .cleanup =              serial_cleanup,
         .install =              serial_install,
         .proc_fops =            &serial_proc_fops,
 };
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 3566129384a4..b08677982525 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -45,8 +45,16 @@
  *
  * void (*shutdown)(struct tty_struct * tty);
  *
- *      This routine is called when a particular tty device is closed for
- *      the last time freeing up the resources.
+ *      This routine is called synchronously when a particular tty device
+ *      is closed for the last time freeing up the resources.
+ *
+ *
+ * void (*cleanup)(struct tty_struct * tty);
+ *
+ *      This routine is called asynchronously when a particular tty device
+ *      is closed for the last time freeing up the resources. This is
+ *      actually the second part of shutdown for routines that might sleep.
+ *
  *
  * int (*write)(struct tty_struct * tty,
  *               const unsigned char *buf, int count);
@@ -233,6 +241,7 @@ struct tty_operations {
         int  (*open)(struct tty_struct * tty, struct file * filp);
         void (*close)(struct tty_struct * tty, struct file * filp);
         void (*shutdown)(struct tty_struct *tty);
+        void (*cleanup)(struct tty_struct *tty);
         int  (*write)(struct tty_struct * tty,
                       const unsigned char *buf, int count);
         int  (*put_char)(struct tty_struct *tty, unsigned char ch);