X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=drivers%2Ftty%2Fpty.c;fp=drivers%2Ftty%2Fpty.c;h=e554393d5551192997dc1048194b76bcc70b62e4;hb=54e8e5fcaae109f0303f52efb24f29bfac79ca86;hp=29b5eeb018560e6f763cd68a6d28e987d5bcebcd;hpb=6054c16e80318d32ee084a0f5620a863ae8cea33;p=firefly-linux-kernel-4.4.55.git

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 29b5eeb01856..e554393d5551 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -339,26 +339,26 @@ static void pty_start(struct tty_struct *tty)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&tty->ctrl_lock, flags);
 	if (tty->link && tty->link->packet) {
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
 		tty->ctrl_status &= ~TIOCPKT_STOP;
 		tty->ctrl_status |= TIOCPKT_START;
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 		wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
 	}
-	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 }
 
 static void pty_stop(struct tty_struct *tty)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&tty->ctrl_lock, flags);
 	if (tty->link && tty->link->packet) {
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
 		tty->ctrl_status &= ~TIOCPKT_START;
 		tty->ctrl_status |= TIOCPKT_STOP;
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 		wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
 	}
-	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 }
 
 /**