fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / drivers / char / n_tty.c

diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index ccad7ae..2bdb014 100644 (file)
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -132,7 +132,7 @@ static void put_tty_queue(unsigned char c, struct tty_struct *tty)
  *     We test the TTY_THROTTLED bit first so that it always
  *     indicates the current state. The decision about whether
  *     it is worth allowing more input has been taken by the caller.
- *     Can sleep, may be called under the atomic_read semaphore but
+ *     Can sleep, may be called under the atomic_read_lock mutex but
  *     this is not guaranteed.
  */
  
@@ -994,7 +994,7 @@ int is_ignored(int sig)
  *     when the ldisc is closed.
  */
  
-static void n_tty_set_termios(struct tty_struct *tty, struct termios * old)
+static void n_tty_set_termios(struct tty_struct *tty, struct ktermios * old)
 {
        if (!tty)
                return;
@@ -1132,7 +1132,7 @@ static inline int input_available_p(struct tty_struct *tty, int amt)
  *     buffer, and once to drain the space from the (physical) beginning of
  *     the buffer to head pointer.
  *
- *     Called under the tty->atomic_read sem and with TTY_DONT_FLIP set
+ *     Called under the tty->atomic_read_lock sem
  *
  */
  
@@ -1151,7 +1151,6 @@ static int copy_from_read_buf(struct tty_struct *tty,
        n = min(*nr, n);
        spin_unlock_irqrestore(&tty->read_lock, flags);
        if (n) {
-               mb();
                retval = copy_to_user(*b, &tty->read_buf[tty->read_tail], n);
                n -= retval;
                spin_lock_irqsave(&tty->read_lock, flags);
@@ -1262,16 +1261,15 @@ do_it_again:
         *      Internal serialization of reads.
         */
        if (file->f_flags & O_NONBLOCK) {
-               if (down_trylock(&tty->atomic_read))
+               if (!mutex_trylock(&tty->atomic_read_lock))
                        return -EAGAIN;
        }
        else {
-               if (down_interruptible(&tty->atomic_read))
+               if (mutex_lock_interruptible(&tty->atomic_read_lock))
                        return -ERESTARTSYS;
        }
 
        add_wait_queue(&tty->read_wait, &wait);
-       set_bit(TTY_DONT_FLIP, &tty->flags);
        while (nr) {
                /* First test for status change. */
                if (tty->packet && tty->link->ctrl_status) {
@@ -1315,9 +1313,7 @@ do_it_again:
                                break;
                        }
                        n_tty_set_room(tty);
-                       clear_bit(TTY_DONT_FLIP, &tty->flags);
                        timeout = schedule_timeout(timeout);
-                       set_bit(TTY_DONT_FLIP, &tty->flags);
                        continue;
                }
                __set_current_state(TASK_RUNNING);
@@ -1384,16 +1380,17 @@ do_it_again:
                 * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
                 * we won't get any more characters.
                 */
-               if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE)
+               if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) {
+                       n_tty_set_room(tty);
                        check_unthrottle(tty);
+               }
 
                if (b - buf >= minimum)
                        break;
                if (time)
                        timeout = time;
        }
-       clear_bit(TTY_DONT_FLIP, &tty->flags);
-       up(&tty->atomic_read);
+       mutex_unlock(&tty->atomic_read_lock);
        remove_wait_queue(&tty->read_wait, &wait);
 
        if (!waitqueue_active(&tty->read_wait))