Bring in the simplified port probe from src/sys/i386/isa/lpt.c

1 files changed, 20 insertions, 26 deletions

diff --git a/sys/dev/ppbus/nlpt.c b/sys/dev/ppbus/nlpt.c
index 4a4e0ff..b28c21f 100644
--- a/sys/dev/ppbus/nlpt.c
+++ b/sys/dev/ppbus/nlpt.c
@@ -47,7 +47,7 @@
  *
  *	from: unknown origin, 386BSD 0.1
  *	From Id: lpt.c,v 1.55.2.1 1996/11/12 09:08:38 phk Exp
- *	$Id: nlpt.c,v 1.12 1999/01/10 12:04:54 nsouch Exp $
+ *	$Id: nlpt.c,v 1.13 1999/01/27 20:09:19 dillon Exp $
  */
 
 /*
@@ -221,6 +221,9 @@ nlpt_port_test(struct lpt_data *sc, u_char data, u_char mask)
 }
 
 /*
+ * Probe simplified by replacing multiple loops with a hardcoded
+ * test pattern - 1999/02/08 des@freebsd.org
+ *
  * New lpt port probe Geoff Rehmet - Rhodes University - 14/2/94
  * Based partially on Rod Grimes' printer probe
  *
@@ -267,38 +270,29 @@ nlpt_port_test(struct lpt_data *sc, u_char data, u_char mask)
 static int
 nlpt_detect(struct lpt_data *sc)
 {
-	int		status;
-	u_char		data;
-	u_char		mask;
-	int		i, error;
+	static u_char	testbyte[18] = {
+		0x55,			/* alternating zeros */
+		0xaa,			/* alternating ones */
+		0xfe, 0xfd, 0xfb, 0xf7,
+		0xef, 0xdf, 0xbf, 0x7f,	/* walking zero */
+		0x01, 0x02, 0x04, 0x08,
+		0x10, 0x20, 0x40, 0x80	/* walking one */
+	};
+	int		i, error, status;
 
 	status = 1;				/* assume success */
 
 	if ((error = lpt_request_ppbus(sc, PPB_DONTWAIT))) {
 		printf(LPT_NAME ": cannot alloc ppbus (%d)!\n", error);
-		status = 0 ; goto end_probe ;
+		status = 0;
+		goto end_probe;
 	}
 
-	mask = 0xff;
-	data = 0x55;				/* Alternating zeros */
-	if (!nlpt_port_test(sc, data, mask))
-		{ status = 0 ; goto end_probe ; }
-
-	data = 0xaa;				/* Alternating ones */
-	if (!nlpt_port_test(sc, data, mask))
-		{ status = 0 ; goto end_probe ; }
-
-	for (i = 0; i < 8; i++)	{		/* Walking zero */
-		data = ~(1 << i);
-		if (!nlpt_port_test(sc, data, mask))
-			{ status = 0 ; goto end_probe ; }
-	}
-
-	for (i = 0; i < 8; i++)	{		/* Walking one */
-		data = (1 << i);
-		if (!nlpt_port_test(sc, data, mask))
-			{ status = 0 ; goto end_probe ; }
-	}
+	for (i = 0; i < 18 && status; i++)
+		if (!nlpt_port_test(sc, testbyte[i], 0xff)) {
+			status = 0;
+			goto end_probe;
+		}
 
 end_probe:
 	/* write 0's to control and data ports */