1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c
index 3c7ac6a3ff80..5a602eb7cd2d 100644
--- a/drivers/char/synclink_gt.c
+++ b/drivers/char/synclink_gt.c
@@ -675,12 +675,14 @@ static int open(struct tty_struct *tty, struct file *filp)
                 goto cleanup;
         }
 
+        mutex_lock(&info->port.mutex);
         info->port.tty->low_latency = (info->port.flags & ASYNC_LOW_LATENCY) ? 1 : 0;
 
         spin_lock_irqsave(&info->netlock, flags);
         if (info->netcount) {
                 retval = -EBUSY;
                 spin_unlock_irqrestore(&info->netlock, flags);
+                mutex_unlock(&info->port.mutex);
                 goto cleanup;
         }
         info->port.count++;
@@ -692,7 +694,7 @@ static int open(struct tty_struct *tty, struct file *filp)
                 if (retval < 0)
                         goto cleanup;
         }
-
+        mutex_unlock(&info->port.mutex);
         retval = block_til_ready(tty, filp, info);
         if (retval) {
                 DBGINFO(("%s block_til_ready rc=%d\n", info->device_name, retval));
@@ -724,12 +726,14 @@ static void close(struct tty_struct *tty, struct file *filp)
         if (tty_port_close_start(&info->port, tty, filp) == 0)
                 goto cleanup;
 
+        mutex_lock(&info->port.mutex);
         if (info->port.flags & ASYNC_INITIALIZED)
                 wait_until_sent(tty, info->timeout);
         flush_buffer(tty);
         tty_ldisc_flush(tty);
 
         shutdown(info);
+        mutex_unlock(&info->port.mutex);
 
         tty_port_close_end(&info->port, tty);
         info->port.tty = NULL;
@@ -740,17 +744,23 @@ cleanup:
 static void hangup(struct tty_struct *tty)
 {
         struct slgt_info *info = tty->driver_data;
+        unsigned long flags;
 
         if (sanity_check(info, tty->name, "hangup"))
                 return;
         DBGINFO(("%s hangup\n", info->device_name));
 
         flush_buffer(tty);
+
+        mutex_lock(&info->port.mutex);
         shutdown(info);
 
+        spin_lock_irqsave(&info->port.lock, flags);
         info->port.count = 0;
         info->port.flags &= ~ASYNC_NORMAL_ACTIVE;
         info->port.tty = NULL;
+        spin_unlock_irqrestore(&info->port.lock, flags);
+        mutex_unlock(&info->port.mutex);
 
         wake_up_interruptible(&info->port.open_wait);
 }