Merge tag 'topic/drm-misc-2015-07-23' of git://anongit.freedesktop.org/drm-intel...

[firefly-linux-kernel-4.4.55.git] / drivers / tty / tty_mutex.c

diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c
index 4486741190c47d52d8079f360081d99085ce82c4..0efcf713b756e5e7eaf95bf7b5f2a744fc7f6dc0 100644 (file)
--- a/drivers/tty/tty_mutex.c
+++ b/drivers/tty/tty_mutex.c
@@ -4,18 +4,8 @@
 #include <linux/semaphore.h>
 #include <linux/sched.h>
 
-/*
- * Nested tty locks are necessary for releasing pty pairs.
- * The stable lock order is master pty first, then slave pty.
- */
-
 /* Legacy tty mutex glue */
 
-enum {
-       TTY_MUTEX_NORMAL,
-       TTY_MUTEX_SLAVE,
-};
-
 /*
  * Getting the big tty mutex.
  */
@@ -46,12 +36,8 @@ EXPORT_SYMBOL(tty_unlock);
 
 void __lockfunc tty_lock_slave(struct tty_struct *tty)
 {
-       if (tty && tty != tty->link) {
-               WARN_ON(!mutex_is_locked(&tty->link->legacy_mutex) ||
-                       !tty->driver->type == TTY_DRIVER_TYPE_PTY ||
-                       !tty->driver->type == PTY_TYPE_SLAVE);
+       if (tty && tty != tty->link)
                tty_lock(tty);
-       }
 }
 
 void __lockfunc tty_unlock_slave(struct tty_struct *tty)
@@ -62,5 +48,5 @@ void __lockfunc tty_unlock_slave(struct tty_struct *tty)
 
 void tty_set_lock_subclass(struct tty_struct *tty)
 {
-       lockdep_set_subclass(&tty->legacy_mutex, TTY_MUTEX_SLAVE);
+       lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
 }