1 files changed, 58 insertions, 0 deletions

diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 0723664fe0ab..b3175f54fe05 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -257,3 +257,61 @@ int tty_port_block_til_ready(struct tty_port *port,
 }
 EXPORT_SYMBOL(tty_port_block_til_ready);
 
+int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct file *filp)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&port->lock, flags);
+        if (tty_hung_up_p(filp)) {
+                spin_unlock_irqrestore(&port->lock, flags);
+                return 0;
+        }
+
+        if( tty->count == 1 && port->count != 1) {
+                printk(KERN_WARNING
+                    "tty_port_close_start: tty->count = 1 port count = %d.\n",
+                                                                port->count);
+                port->count = 1;
+        }
+        if (--port->count < 0) {
+                printk(KERN_WARNING "tty_port_close_start: count = %d\n",
+                                                                port->count);
+                port->count = 0;
+        }
+
+        if (port->count) {
+                spin_unlock_irqrestore(&port->lock, flags);
+                return 0;
+        }
+        port->flags |= ASYNC_CLOSING;
+        tty->closing = 1;
+        spin_unlock_irqrestore(&port->lock, flags);
+        if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
+                tty_wait_until_sent(tty, port->closing_wait);
+        return 1;
+}
+EXPORT_SYMBOL(tty_port_close_start);
+
+void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
+{
+        unsigned long flags;
+
+        tty_ldisc_flush(tty);
+
+        spin_lock_irqsave(&port->lock, flags);
+        tty->closing = 0;
+
+        if (port->blocked_open) {
+                spin_unlock_irqrestore(&port->lock, flags);
+                if (port->close_delay) {
+                        msleep_interruptible(
+                                jiffies_to_msecs(port->close_delay));
+                }
+                spin_lock_irqsave(&port->lock, flags);
+                wake_up_interruptible(&port->open_wait);
+        }
+        port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING);
+        wake_up_interruptible(&port->close_wait);
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+EXPORT_SYMBOL(tty_port_close_end);