From 84c6b9dbd7f4ff0b2319c6bede7a69e95c220642 Mon Sep 17 00:00:00 2001
From: wrstuden <wrstuden@NetBSD.org>
Date: Thu, 5 Mar 1998 22:03:34 +0000
Subject: [PATCH] Make zs_iflush not loop indefinitly. Some Mac PowerBooks lie
 about having two SCC channels, and can get stuck in an infinite loop. This
 change stops after flushing 4 bytes. Might need upping to 8 bytes if we
 support 85230 ESCC's.

Idea bounced off of scottr & gwr
---
 sys/dev/ic/z8530sc.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/sys/dev/ic/z8530sc.c b/sys/dev/ic/z8530sc.c
index a3275e106768..9380e368bc50 100644
--- a/sys/dev/ic/z8530sc.c
+++ b/sys/dev/ic/z8530sc.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: z8530sc.c,v 1.7 1998/02/19 21:26:10 mycroft Exp $	*/
+/*	$NetBSD: z8530sc.c,v 1.8 1998/03/05 22:03:34 wrstuden Exp $	*/
 
 /*
  * Copyright (c) 1994 Gordon W. Ross
@@ -92,8 +92,13 @@ zs_iflush(cs)
 	struct zs_chanstate *cs;
 {
 	u_char c, rr0, rr1;
+	int i;
 
-	for (;;) {
+	/*
+	 * Count how many times we loop. Some systems, such as some
+	 * Apple PowerBooks, claim to have SCC's which they really don't.
+	 */
+	for (i=0; i<4; i++) {
 		/* Is there input available? */
 		rr0 = zs_read_csr(cs);
 		if ((rr0 & ZSRR0_RX_READY) == 0)