revert android-tegra-2.6.36-honeycomb-mr1-9001adc to v2.6.36

[firefly-linux-kernel-4.4.55.git] / drivers / char / tty_ldisc.c

diff --git a/drivers/char/tty_ldisc.c b/drivers/char/tty_ldisc.c
index 4214d58276f709a8743c03f431cef5b6360c2b46..412f9775d19c5f2deee27b2174532e35ab3e14d1 100644 (file)
--- a/drivers/char/tty_ldisc.c
+++ b/drivers/char/tty_ldisc.c
@@ -47,7 +47,6 @@
 
 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];
 
@@ -84,7 +83,6 @@ static void put_ldisc(struct tty_ldisc *ld)
                return;
        }
        local_irq_restore(flags);
-       wake_up(&tty_ldisc_idle);
 }
 
 /**
@@ -454,8 +452,6 @@ static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
                 /* BTM here locks versus a hangup event */
                WARN_ON(!tty_locked());
                ret = ld->ops->open(tty);
-               if (ret)
-                       clear_bit(TTY_LDISC_OPEN, &tty->flags);
                return ret;
        }
        return 0;
@@ -534,23 +530,6 @@ static int tty_ldisc_halt(struct tty_struct *tty)
        return cancel_delayed_work_sync(&tty->buf.work);
 }
 
-/**
- *     tty_ldisc_wait_idle     -       wait for the ldisc to become idle
- *     @tty: tty to wait for
- *
- *     Wait for the line discipline to become idle. The discipline must
- *     have been halted for this to guarantee it remains idle.
- */
-static int tty_ldisc_wait_idle(struct tty_struct *tty)
-{
-       int ret;
-       ret = wait_event_interruptible_timeout(tty_ldisc_idle,
-                       atomic_read(&tty->ldisc->users) == 1, 5 * HZ);
-       if (ret < 0)
-               return ret;
-       return ret > 0 ? 0 : -EBUSY;
-}
-
 /**
  *     tty_set_ldisc           -       set line discipline
  *     @tty: the terminal to set
@@ -655,17 +634,8 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 
        flush_scheduled_work();
 
-       retval = tty_ldisc_wait_idle(tty);
-
        tty_lock();
        mutex_lock(&tty->ldisc_mutex);
-
-       /* handle wait idle failure locked */
-       if (retval) {
-               tty_ldisc_put(new_ldisc);
-               goto enable;
-       }
-
        if (test_bit(TTY_HUPPED, &tty->flags)) {
                /* We were raced by the hangup method. It will have stomped
                   the ldisc data and closed the ldisc down */
@@ -699,7 +669,6 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 
        tty_ldisc_put(o_ldisc);
 
-enable:
        /*
         *      Allow ldisc referencing to occur again
         */
@@ -745,12 +714,9 @@ static void tty_reset_termios(struct tty_struct *tty)
  *     state closed
  */
 
-static int tty_ldisc_reinit(struct tty_struct *tty, int ldisc)
+static void tty_ldisc_reinit(struct tty_struct *tty, int ldisc)
 {
-       struct tty_ldisc *ld = tty_ldisc_get(ldisc);
-
-       if (IS_ERR(ld))
-               return -1;
+       struct tty_ldisc *ld;
 
        tty_ldisc_close(tty, tty->ldisc);
        tty_ldisc_put(tty->ldisc);
@@ -758,10 +724,10 @@ static int tty_ldisc_reinit(struct tty_struct *tty, int ldisc)
        /*
         *      Switch the line discipline back
         */
+       ld = tty_ldisc_get(ldisc);
+       BUG_ON(IS_ERR(ld));
        tty_ldisc_assign(tty, ld);
        tty_set_termios_ldisc(tty, ldisc);
-
-       return 0;
 }
 
 /**
@@ -836,16 +802,13 @@ void tty_ldisc_hangup(struct tty_struct *tty)
           a FIXME */
        if (tty->ldisc) {       /* Not yet closed */
                if (reset == 0) {
-
-                       if (!tty_ldisc_reinit(tty, tty->termios->c_line))
-                               err = tty_ldisc_open(tty, tty->ldisc);
-                       else
-                               err = 1;
+                       tty_ldisc_reinit(tty, tty->termios->c_line);
+                       err = tty_ldisc_open(tty, tty->ldisc);
                }
                /* If the re-open fails or we reset then go to N_TTY. The
                   N_TTY open cannot fail */
                if (reset || err) {
-                       BUG_ON(tty_ldisc_reinit(tty, N_TTY));
+                       tty_ldisc_reinit(tty, N_TTY);
                        WARN_ON(tty_ldisc_open(tty, tty->ldisc));
                }
                tty_ldisc_enable(tty);