1 files changed, 39 insertions, 1 deletions

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index a3bd3a3f41f3..68aa4da01865 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1938,9 +1938,24 @@ static void uart_change_pm(struct uart_state *state, int pm_state)
         }
 }
 
+struct uart_match {
+        struct uart_port *port;
+        struct uart_driver *driver;
+};
+
+static int serial_match_port(struct device *dev, void *data)
+{
+        struct uart_match *match = data;
+        dev_t devt = MKDEV(match->driver->major, match->driver->minor) + match->port->line;
+
+        return dev->devt == devt; /* Actually, only one tty per port */
+}
+
 int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
 {
         struct uart_state *state = drv->state + port->line;
+        struct device *tty_dev;
+        struct uart_match match = {port, drv};
 
         mutex_lock(&state->mutex);
 
@@ -1951,6 +1966,15 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
         }
 #endif
 
+        tty_dev = device_find_child(port->dev, &match, serial_match_port);
+        if (device_may_wakeup(tty_dev)) {
+                enable_irq_wake(port->irq);
+                put_device(tty_dev);
+                mutex_unlock(&state->mutex);
+                return 0;
+        }
+        port->suspended = 1;
+
         if (state->info && state->info->flags & UIF_INITIALIZED) {
                 const struct uart_ops *ops = port->ops;
 
@@ -1999,6 +2023,13 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
         }
 #endif
 
+        if (!port->suspended) {
+                disable_irq_wake(port->irq);
+                mutex_unlock(&state->mutex);
+                return 0;
+        }
+        port->suspended = 0;
+
         uart_change_pm(state, 0);
 
         /*
@@ -2278,6 +2309,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
 {
         struct uart_state *state;
         int ret = 0;
+        struct device *tty_dev;
 
         BUG_ON(in_interrupt());
 
@@ -2314,7 +2346,13 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
          * Register the port whether it's detected or not.  This allows
          * setserial to be used to alter this ports parameters.
          */
-        tty_register_device(drv->tty_driver, port->line, port->dev);
+        tty_dev = tty_register_device(drv->tty_driver, port->line, port->dev);
+        if (likely(!IS_ERR(tty_dev))) {
+                device_can_wakeup(tty_dev) = 1;
+                device_set_wakeup_enable(tty_dev, 0);
+        } else
+                printk(KERN_ERR "Cannot register tty device on line %d\n",
+                       port->line);
 
         /*
          * Ensure UPF_DEAD is not set.