diff --git a/drivers/char/n_hdlc.c b/drivers/char/n_hdlc.c
index 337a87f..37f7d34 100644
--- a/drivers/char/n_hdlc.c
+++ b/drivers/char/n_hdlc.c
@@ -780,13 +780,14 @@
 		poll_wait(filp, &tty->write_wait, wait);
 
 		/* set bits for operations that won't block */
-		if(n_hdlc->rx_buf_list.head)
+		if (n_hdlc->rx_buf_list.head)
 			mask |= POLLIN | POLLRDNORM;	/* readable */
 		if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
 			mask |= POLLHUP;
-		if(tty_hung_up_p(filp))
+		if (tty_hung_up_p(filp))
 			mask |= POLLHUP;
-		if(n_hdlc->tx_free_buf_list.head)
+		if (!tty_is_writelocked(tty) &&
+				n_hdlc->tx_free_buf_list.head)
 			mask |= POLLOUT | POLLWRNORM;	/* writable */
 	}
 	return mask;
@@ -861,7 +862,7 @@
 	spin_lock_irqsave(&list->spinlock,flags);
 	
 	buf->link=NULL;
-	if(list->tail)
+	if (list->tail)
 		list->tail->link = buf;
 	else
 		list->head = buf;