serial: move delta_msr_wait into the tty_port

This is used by various drivers not just serial and can be extracted
as commonality

Signed-off-by: Alan Cox <alan@linux.intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 549bd0fa8bb6..c767e30a1425 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -23,6 +23,7 @@ void tty_port_init(struct tty_port *port)
         memset(port, 0, sizeof(*port));
         init_waitqueue_head(&port->open_wait);
         init_waitqueue_head(&port->close_wait);
+        init_waitqueue_head(&port->delta_msr_wait);
         mutex_init(&port->mutex);
         spin_lock_init(&port->lock);
         port->close_delay = (50 * HZ) / 100;
@@ -124,6 +125,7 @@ void tty_port_hangup(struct tty_port *port)
         port->tty = NULL;
         spin_unlock_irqrestore(&port->lock, flags);
         wake_up_interruptible(&port->open_wait);
+        wake_up_interruptible(&port->delta_msr_wait);
         tty_port_shutdown(port);
 }
 EXPORT_SYMBOL(tty_port_hangup);