TTY: serial, use tty_port_close_start helper

After the previous patches, the code is almost identical. There are
few differences in the helper code:
1) flush_buffer when flow_stopped
   * when a user doesn't care about the data, delete it anyways
2) ASYNCB_INITIALIZED test before wait_until_sent_from
   * obviously, there is nothing to wait for if the port is dead
3) drain_delay wait
   * we don't set drain_delay

So we can use the helper now. It indeed removes a bunch of duplicated
code.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 2b1ee7c..fcb5342 100644 (file)
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1267,46 +1267,8 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 
        pr_debug("uart_close(%d) called\n", uport->line);
 
-       spin_lock_irqsave(&port->lock, flags);
-
-       if (tty_hung_up_p(filp)) {
-               spin_unlock_irqrestore(&port->lock, flags);
+       if (tty_port_close_start(port, tty, filp) == 0)
                return;
-       }
-
-       if ((tty->count == 1) && (port->count != 1)) {
-               /*
-                * Uh, oh.  tty->count is 1, which means that the tty
-                * structure will be freed.  port->count should always
-                * be one in these conditions.  If it's greater than
-                * one, we've got real problems, since it means the
-                * serial port won't be shutdown.
-                */
-               printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
-                      "port->count is %d\n", port->count);
-               port->count = 1;
-       }
-       if (--port->count < 0) {
-               printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
-                      tty->name, port->count);
-               port->count = 0;
-       }
-       if (port->count) {
-               spin_unlock_irqrestore(&port->lock, flags);
-               return;
-       }
-
-       /*
-        * Now we wait for the transmit buffer to clear; and we notify
-        * the line discipline to only process XON/XOFF characters by
-        * setting tty->closing.
-        */
-       set_bit(ASYNCB_CLOSING, &port->flags);
-       tty->closing = 1;
-       spin_unlock_irqrestore(&port->lock, flags);
-
-       if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
-               tty_wait_until_sent_from_close(tty, port->closing_wait);
 
        /*
         * At this point, we stop accepting input.  To do this, we