Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

===================================================================
RCS file: /ftp/cvs/cvsroot/src/sys/dev/ic/com.c,v
rcsdiff: /ftp/cvs/cvsroot/src/sys/dev/ic/com.c,v: warning: Unknown phrases like `commitid ...;' are present.
retrieving revision 1.264.2.2
retrieving revision 1.265
diff -u -p -r1.264.2.2 -r1.265
--- src/sys/dev/ic/com.c	2007/11/21 21:19:33	1.264.2.2
+++ src/sys/dev/ic/com.c	2007/10/19 11:59:49	1.265
@@ -1,4 +1,4 @@
-/*	$NetBSD: com.c,v 1.264.2.2 2007/11/21 21:19:33 bouyer Exp $	*/
+/*	$NetBSD: com.c,v 1.265 2007/10/19 11:59:49 ad Exp $	*/
 
 /*-
  * Copyright (c) 1998, 1999, 2004 The NetBSD Foundation, Inc.
@@ -73,7 +73,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: com.c,v 1.264.2.2 2007/11/21 21:19:33 bouyer Exp $");
+__KERNEL_RCSID(0, "$NetBSD: com.c,v 1.265 2007/10/19 11:59:49 ad Exp $");
 
 #include "opt_com.h"
 #include "opt_ddb.h"
@@ -1660,8 +1660,16 @@ comstart(struct tty *tp)
 		goto out;
 	if (sc->sc_tx_stopped)
 		goto out;
-	if (!ttypull(tp))
-		goto out;
+
+	if (tp->t_outq.c_cc <= tp->t_lowat) {
+		if (ISSET(tp->t_state, TS_ASLEEP)) {
+			CLR(tp->t_state, TS_ASLEEP);
+			wakeup(&tp->t_outq);
+		}
+		selwakeup(&tp->t_wsel);
+		if (tp->t_outq.c_cc == 0)
+			goto out;
+	}
 
 	/* Grab the first contiguous region of buffer space. */
 	{