3 files changed, 26 insertions, 13 deletions

diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 45e248c2f43c..87eebfe03c61 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -150,9 +150,11 @@ void chan_enable_winch(struct chan *chan, struct tty_struct *tty)
 static void line_timer_cb(struct work_struct *work)
 {
         struct line *line = container_of(work, struct line, task.work);
+        struct tty_struct *tty = tty_port_tty_get(&line->port);
 
         if (!line->throttled)
-                chan_interrupt(line, line->tty, line->driver->read_irq);
+                chan_interrupt(line, tty, line->driver->read_irq);
+        tty_kref_put(tty);
 }
 
 int enable_chan(struct line *line)
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index acfd0e0fd0c9..fb6e4ea09921 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -19,9 +19,11 @@ static irqreturn_t line_interrupt(int irq, void *data)
 {
         struct chan *chan = data;
         struct line *line = chan->line;
+        struct tty_struct *tty = tty_port_tty_get(&line->port);
 
         if (line)
-                chan_interrupt(line, line->tty, irq);
+                chan_interrupt(line, tty, irq);
+        tty_kref_put(tty);
         return IRQ_HANDLED;
 }
 
@@ -333,7 +335,7 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
 {
         struct chan *chan = data;
         struct line *line = chan->line;
-        struct tty_struct *tty = line->tty;
+        struct tty_struct *tty;
         int err;
 
         /*
@@ -352,10 +354,13 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
         }
         spin_unlock(&line->lock);
 
+        tty = tty_port_tty_get(&line->port);
         if (tty == NULL)
                 return IRQ_NONE;
 
         tty_wakeup(tty);
+        tty_kref_put(tty);
+
         return IRQ_HANDLED;
 }
 
@@ -404,12 +409,12 @@ int line_open(struct line *lines, struct tty_struct *tty)
                 goto out_unlock;
 
         err = 0;
-        if (line->count++)
+        if (line->port.count++)
                 goto out_unlock;
 
         BUG_ON(tty->driver_data);
         tty->driver_data = line;
-        line->tty = tty;
+        tty_port_tty_set(&line->port, tty);
 
         err = enable_chan(line);
         if (err) /* line_close() will be called by our caller */
@@ -446,10 +451,10 @@ void line_close(struct tty_struct *tty, struct file * filp)
         mutex_lock(&line->count_lock);
         BUG_ON(!line->valid);
 
-        if (--line->count)
+        if (--line->port.count)
                 goto out_unlock;
 
-        line->tty = NULL;
+        tty_port_tty_set(&line->port, NULL);
         tty->driver_data = NULL;
 
         if (line->sigio) {
@@ -478,7 +483,7 @@ int setup_one_line(struct line *lines, int n, char *init,
 
         mutex_lock(&line->count_lock);
 
-        if (line->count) {
+        if (line->port.count) {
                 *error_out = "Device is already open";
                 goto out;
         }
@@ -610,9 +615,15 @@ int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
         mutex_lock(&line->count_lock);
         if (!line->valid)
                 CONFIG_CHUNK(str, size, n, "none", 1);
-        else if (line->tty == NULL)
-                CONFIG_CHUNK(str, size, n, line->init_str, 1);
-        else n = chan_config_string(line, str, size, error_out);
+        else {
+                struct tty_struct *tty = tty_port_tty_get(&line->port);
+                if (tty == NULL) {
+                        CONFIG_CHUNK(str, size, n, line->init_str, 1);
+                } else {
+                        n = chan_config_string(line, str, size, error_out);
+                        tty_kref_put(tty);
+                }
+        }
         mutex_unlock(&line->count_lock);
 
         return n;
@@ -663,6 +674,7 @@ int register_lines(struct line_driver *line_driver,
         driver->init_termios = tty_std_termios;
         
         for (i = 0; i < nlines; i++) {
+                tty_port_init(&lines[i].port);
                 spin_lock_init(&lines[i].lock);
                 mutex_init(&lines[i].count_lock);
                 lines[i].driver = line_driver;
diff --git a/arch/um/drivers/line.h b/arch/um/drivers/line.h
index 0a1834719dba..5b3d4fbdec18 100644
--- a/arch/um/drivers/line.h
+++ b/arch/um/drivers/line.h
@@ -32,9 +32,8 @@ struct line_driver {
 };
 
 struct line {
-        struct tty_struct *tty;
+        struct tty_port port;
         struct mutex count_lock;
-        unsigned long count;
         int valid;
 
         char *init_str;