memcg, slab: do not destroy children caches if parent has aliases

[karo-tx-linux.git] / include / linux / tty.h

diff --git a/include/linux/tty.h b/include/linux/tty.h
index 90b4fdc8a61f14fcd8753bc5d7d55d89924e9302..1c3316a47d7e0386d1ede163c4f795275efc8130 100644 (file)
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -208,7 +208,7 @@ struct tty_port {
        wait_queue_head_t       delta_msr_wait; /* Modem status change */
        unsigned long           flags;          /* TTY flags ASY_*/
        unsigned char           console:1,      /* port is a console */
-                               low_latency:1;  /* direct buffer flush */
+                               low_latency:1;  /* optional: tune for latency */
        struct mutex            mutex;          /* Locking */
        struct mutex            buf_mutex;      /* Buffer alloc lock */
        unsigned char           *xmit_buf;      /* Optional buffer */
@@ -518,9 +518,9 @@ extern void tty_port_put(struct tty_port *port);
 
 static inline struct tty_port *tty_port_get(struct tty_port *port)
 {
-       if (port)
-               kref_get(&port->kref);
-       return port;
+       if (port && kref_get_unless_zero(&port->kref))
+               return port;
+       return NULL;
 }
 
 /* If the cts flow control is enabled, return true. */