Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso...

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

diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index f597e88a705d1fa8e65cf36ae98a61f84f20b9a3..c94d2349dd0620dd183645ee37ddced4551e9ccd 100644 (file)
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -140,6 +140,10 @@ EXPORT_SYMBOL(tty_port_destroy);
 static void tty_port_destructor(struct kref *kref)
 {
        struct tty_port *port = container_of(kref, struct tty_port, kref);
+
+       /* check if last port ref was dropped before tty release */
+       if (WARN_ON(port->itty))
+               return;
        if (port->xmit_buf)
                free_page((unsigned long)port->xmit_buf);
        tty_port_destroy(port);
@@ -480,8 +484,6 @@ int tty_port_close_start(struct tty_port *port,
 
        if (port->count) {
                spin_unlock_irqrestore(&port->lock, flags);
-               if (port->ops->drop)
-                       port->ops->drop(port);
                return 0;
        }
        set_bit(ASYNCB_CLOSING, &port->flags);
@@ -500,9 +502,7 @@ int tty_port_close_start(struct tty_port *port,
        /* Flush the ldisc buffering */
        tty_ldisc_flush(tty);
 
-       /* Don't call port->drop for the last reference. Callers will want
-          to drop the last active reference in ->shutdown() or the tty
-          shutdown path */
+       /* Report to caller this is the last port reference */
        return 1;
 }
 EXPORT_SYMBOL(tty_port_close_start);