tty: Introduce some close helpers for ports

[safe/jmp/linux-2.6] / drivers / char / tty_port.c

diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 0723664..b3175f5 100644 (file)
--- 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);