1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/char/synclinkmp.c b/drivers/char/synclinkmp.c
index 8da976bd7314..ac447c7eb572 100644
--- a/drivers/char/synclinkmp.c
+++ b/drivers/char/synclinkmp.c
@@ -812,13 +812,15 @@ 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;
@@ -834,6 +836,7 @@ cleanup:
 static void hangup(struct tty_struct *tty)
 {
         SLMP_INFO *info = tty->driver_data;
+        unsigned long flags;
 
         if (debug_level >= DEBUG_LEVEL_INFO)
                 printk("%s(%d):%s hangup()\n",
@@ -842,12 +845,16 @@ static void hangup(struct tty_struct *tty)
         if (sanity_check(info, tty->name, "hangup"))
                 return;
 
+        mutex_lock(&info->port.mutex);
         flush_buffer(tty);
         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);
 }