1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/char/amiserial.c b/drivers/char/amiserial.c
index 1b21a7adeb58..8228e61bb54d 100644
--- a/drivers/char/amiserial.c
+++ b/drivers/char/amiserial.c
@@ -1528,6 +1528,7 @@ static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 {
         struct async_struct * info = tty->driver_data;
         unsigned long orig_jiffies, char_time;
+        int tty_was_locked = tty_locked();
         int lsr;
 
         if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
@@ -1538,7 +1539,12 @@ static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 
         orig_jiffies = jiffies;
 
-        tty_lock_nested(); /* tty_wait_until_sent is called from lots of places */
+        /*
+         * tty_wait_until_sent is called from lots of places,
+         * with or without the BTM.
+         */
+        if (!tty_was_locked)
+                tty_lock();
         /*
          * Set the check interval to be 1/5 of the estimated time to
          * send a single character, and make it at least 1.  The check
@@ -1579,7 +1585,8 @@ static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
                         break;
         }
         __set_current_state(TASK_RUNNING);
-        tty_unlock();
+        if (!tty_was_locked)
+                tty_unlock();
 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
         printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
 #endif