From 1f855b025c1c86d8d1b976515fe216864046e2b2 Mon Sep 17 00:00:00 2001
From: Miod Vallat <miod@cvs.openbsd.org>
Date: Tue, 30 Apr 2002 20:56:16 +0000
Subject: Correctly handle old controllers with a relaxed aux port behaviour.
 This allows the mouse port to become available on AlphaStation machines, as
 well as on some older x86 machines.

From NetBSD.

Tested by various people on alpha and i386, no regression discovered.
---
 sys/dev/ic/pckbc.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

(limited to 'sys')

diff --git a/sys/dev/ic/pckbc.c b/sys/dev/ic/pckbc.c
index 38e59f87450..b67e61a8362 100644
--- a/sys/dev/ic/pckbc.c
+++ b/sys/dev/ic/pckbc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: pckbc.c,v 1.3 2002/03/14 01:26:55 millert Exp $ */
+/* $OpenBSD: pckbc.c,v 1.4 2002/04/30 20:56:15 miod Exp $ */
 /* $NetBSD: pckbc.c,v 1.5 2000/06/09 04:58:35 soda Exp $ */
 
 /*
@@ -360,14 +360,24 @@ pckbc_attach(sc)
 	}
 	bus_space_write_1(iot, ioh_d, 0, 0x5a);	/* a random value */
 	res = pckbc_poll_data1(iot, ioh_d, ioh_c, PCKBC_AUX_SLOT, 1);
-	if (res == 0x5a) {
+	if (res != -1) {
+		/*
+		 * In most cases, the 0x5a gets echoed.
+		 * Some old controllers (Gateway 2000 circa 1993)
+		 * return 0xfe here.
+		 * We are satisfied if there is anything in the
+		 * aux output buffer.
+		 */
+#ifdef PCKBCDEBUG
+		printf("kbc: aux echo: %x\n", res);
+#endif
 		t->t_haveaux = 1;
 		if (pckbc_attach_slot(sc, PCKBC_AUX_SLOT))
 			cmdbits |= KC8_MENABLE;
 	}
 #ifdef PCKBCDEBUG
-	  else
-		printf("kbc: aux echo: %x\n", res);
+	else
+		printf("kbc: aux echo test failed\n");
 #endif
 
 nomouse:
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