1 files changed, 19 insertions, 18 deletions

diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 24b95db75d8..173a9000a6c 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -28,7 +28,6 @@
 
 static DEFINE_SPINLOCK(tty_ldisc_lock);
 static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
-static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_idle);
 /* Line disc dispatch table */
 static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
 
@@ -65,7 +64,7 @@ static void put_ldisc(struct tty_ldisc *ld)
                 return;
         }
         local_irq_restore(flags);
-        wake_up(&tty_ldisc_idle);
+        wake_up(&ld->wq_idle);
 }
 
 /**
@@ -200,6 +199,8 @@ static struct tty_ldisc *tty_ldisc_get(int disc)
 
         ld->ops = ldops;
         atomic_set(&ld->users, 1);
+        init_waitqueue_head(&ld->wq_idle);
+
         return ld;
 }
 
@@ -538,7 +539,7 @@ static void tty_ldisc_flush_works(struct tty_struct *tty)
 static int tty_ldisc_wait_idle(struct tty_struct *tty, long timeout)
 {
         long ret;
-        ret = wait_event_timeout(tty_ldisc_idle,
+        ret = wait_event_timeout(tty->ldisc->wq_idle,
                         atomic_read(&tty->ldisc->users) == 1, timeout);
         return ret > 0 ? 0 : -EBUSY;
 }
@@ -567,7 +568,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
         if (IS_ERR(new_ldisc))
                 return PTR_ERR(new_ldisc);
 
-        tty_lock();
+        tty_lock(tty);
         /*
          *      We need to look at the tty locking here for pty/tty pairs
          *      when both sides try to change in parallel.
@@ -581,12 +582,12 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
          */
 
         if (tty->ldisc->ops->num == ldisc) {
-                tty_unlock();
+                tty_unlock(tty);
                 tty_ldisc_put(new_ldisc);
                 return 0;
         }
 
-        tty_unlock();
+        tty_unlock(tty);
         /*
          *      Problem: What do we do if this blocks ?
          *      We could deadlock here
@@ -594,7 +595,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 
         tty_wait_until_sent(tty, 0);
 
-        tty_lock();
+        tty_lock(tty);
         mutex_lock(&tty->ldisc_mutex);
 
         /*
@@ -604,10 +605,10 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 
         while (test_bit(TTY_LDISC_CHANGING, &tty->flags)) {
                 mutex_unlock(&tty->ldisc_mutex);
-                tty_unlock();
+                tty_unlock(tty);
                 wait_event(tty_ldisc_wait,
                         test_bit(TTY_LDISC_CHANGING, &tty->flags) == 0);
-                tty_lock();
+                tty_lock(tty);
                 mutex_lock(&tty->ldisc_mutex);
         }
 
@@ -622,7 +623,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 
         o_ldisc = tty->ldisc;
 
-        tty_unlock();
+        tty_unlock(tty);
         /*
          *      Make sure we don't change while someone holds a
          *      reference to the line discipline. The TTY_LDISC bit
@@ -649,7 +650,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 
         retval = tty_ldisc_wait_idle(tty, 5 * HZ);
 
-        tty_lock();
+        tty_lock(tty);
         mutex_lock(&tty->ldisc_mutex);
 
         /* handle wait idle failure locked */
@@ -664,7 +665,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
                 clear_bit(TTY_LDISC_CHANGING, &tty->flags);
                 mutex_unlock(&tty->ldisc_mutex);
                 tty_ldisc_put(new_ldisc);
-                tty_unlock();
+                tty_unlock(tty);
                 return -EIO;
         }
 
@@ -707,7 +708,7 @@ enable:
         if (o_work)
                 schedule_work(&o_tty->buf.work);
         mutex_unlock(&tty->ldisc_mutex);
-        tty_unlock();
+        tty_unlock(tty);
         return retval;
 }
 
@@ -815,11 +816,11 @@ void tty_ldisc_hangup(struct tty_struct *tty)
          * need to wait for another function taking the BTM
          */
         clear_bit(TTY_LDISC, &tty->flags);
-        tty_unlock();
+        tty_unlock(tty);
         cancel_work_sync(&tty->buf.work);
         mutex_unlock(&tty->ldisc_mutex);
 retry:
-        tty_lock();
+        tty_lock(tty);
         mutex_lock(&tty->ldisc_mutex);
 
         /* At this point we have a closed ldisc and we want to
@@ -830,7 +831,7 @@ retry:
                 if (atomic_read(&tty->ldisc->users) != 1) {
                         char cur_n[TASK_COMM_LEN], tty_n[64];
                         long timeout = 3 * HZ;
-                        tty_unlock();
+                        tty_unlock(tty);
 
                         while (tty_ldisc_wait_idle(tty, timeout) == -EBUSY) {
                                 timeout = MAX_SCHEDULE_TIMEOUT;
@@ -911,10 +912,10 @@ void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
          * race with the set_ldisc code path.
          */
 
-        tty_unlock();
+        tty_unlock(tty);
         tty_ldisc_halt(tty);
         tty_ldisc_flush_works(tty);
-        tty_lock();
+        tty_lock(tty);
 
         mutex_lock(&tty->ldisc_mutex);
         /*