diff --git a/[refs] b/[refs]
index 0103ea452c99..b25766daf034 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 768aec0b5bccbd460bcf6e9131f19b5a26f3862d
+refs/heads/master: c72f527c104cae8e767e714574238b5550879e0c
diff --git a/trunk/drivers/char/n_hdlc.c b/trunk/drivers/char/n_hdlc.c
index ed4e03333ab4..69ec6399c714 100644
--- a/trunk/drivers/char/n_hdlc.c
+++ b/trunk/drivers/char/n_hdlc.c
@@ -677,6 +677,10 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
 	/* Allocate transmit buffer */
 	/* sleep until transmit buffer available */		
 	while (!(tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list))) {
+		if (file->f_flags & O_NONBLOCK) {
+			error = -EAGAIN;
+			break;
+		}
 		schedule();
 			
 		n_hdlc = tty2n_hdlc (tty);