X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=drivers%2Ftty%2Ftty_ldisc.c;h=3737f55272d2c1184463edc3714f89fb2724730e;hb=28023d2a8e9121b1b06c3b46e523c3c7a3e8b530;hp=6368dd95e13740ffd52f4a54e65ed11179ca41b0;hpb=276a661a4d75258b3aa28701b0748f99b773563b;p=firefly-linux-kernel-4.4.55.git

diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 6368dd95e137..3737f55272d2 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -397,19 +397,17 @@ static void __lockfunc tty_ldisc_unlock_pair(struct tty_struct *tty,
  *	tty_ldisc_flush	-	flush line discipline queue
  *	@tty: tty
  *
- *	Flush the line discipline queue (if any) for this tty. If there
- *	is no line discipline active this is a no-op.
+ *	Flush the line discipline queue (if any) and the tty flip buffers
+ *	for this tty.
  */
 
 void tty_ldisc_flush(struct tty_struct *tty)
 {
 	struct tty_ldisc *ld = tty_ldisc_ref(tty);
-	if (ld) {
-		if (ld->ops->flush_buffer)
-			ld->ops->flush_buffer(tty);
+
+	tty_buffer_flush(tty, ld);
+	if (ld)
 		tty_ldisc_deref(ld);
-	}
-	tty_buffer_flush(tty);
 }
 EXPORT_SYMBOL_GPL(tty_ldisc_flush);
 
@@ -574,8 +572,11 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 		tty_ldisc_restore(tty, old_ldisc);
 	}
 
-	if (tty->ldisc->ops->num != old_ldisc->ops->num && tty->ops->set_ldisc)
+	if (tty->ldisc->ops->num != old_ldisc->ops->num && tty->ops->set_ldisc) {
+		down_read(&tty->termios_rwsem);
 		tty->ops->set_ldisc(tty);
+		up_read(&tty->termios_rwsem);
+	}
 
 	/* At this point we hold a reference to the new ldisc and a
 	   reference to the old ldisc, or we hold two references to