Use SCSI_DELAY only once. Document it. Default to no delay.

Fixes two second system 'freeze' when umass device plugged in. Speeds
up boot by not waiting for a minimum of 2 seconds at each scsi bus.

ok jmc@ pedro@ deraadt@

3 files changed, 13 insertions, 12 deletions

diff --git a/share/man/man4/options.4 b/share/man/man4/options.4
index 55dedfabb0d..69d18ea7097 100644
--- a/share/man/man4/options.4
+++ b/share/man/man4/options.4
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: options.4,v 1.169 2005/11/06 17:50:06 kettenis Exp $
+.\"	$OpenBSD: options.4,v 1.170 2005/11/13 03:27:41 krw Exp $
 .\"	$NetBSD: options.4,v 1.21 1997/06/25 03:13:00 thorpej Exp $
 .\"
 .\" Copyright (c) 1998 Theo de Raadt
@@ -871,6 +871,11 @@ which affects processor cycle counter.
 .El
 .Ss SCSI Subsystem Options
 .Bl -ohang
+.It Cd option SCSI_DELAY=value
+Delay for
+.Ar value
+seconds before starting to probe the first SCSI bus.
+This can be used if a SCSI device needs extra time to get ready.
 .It Cd option SCSITERSE
 Terser SCSI error messages.
 This omits the table for decoding ASC/ASCQ info, saving about 30KB.
diff --git a/sys/scsi/scsi_base.c b/sys/scsi/scsi_base.c
index badb63d741a..570166d7ead 100644
--- a/sys/scsi/scsi_base.c
+++ b/sys/scsi/scsi_base.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: scsi_base.c,v 1.95 2005/11/13 02:39:45 krw Exp $	*/
+/*	$OpenBSD: scsi_base.c,v 1.96 2005/11/13 03:27:42 krw Exp $	*/
 /*	$NetBSD: scsi_base.c,v 1.43 1997/04/02 02:29:36 mycroft Exp $	*/
 
 /*
@@ -79,6 +79,11 @@ scsi_init()
 		return;
 	scsi_init_done = 1;
 
+#if defined(SCSI_DELAY) && SCSI_DELAY > 0
+	/* Historical. Older buses may need a moment to stabilize. */
+	delay(1000000 * SCSI_DELAY);
+#endif
+
 	/* Initialize the scsi_xfer pool. */
 	pool_init(&scsi_xfer_pool, sizeof(struct scsi_xfer), 0,
 	    0, 0, "scxspl", NULL);
diff --git a/sys/scsi/scsiconf.c b/sys/scsi/scsiconf.c
index 38a3e56449a..f53c7d92b28 100644
--- a/sys/scsi/scsiconf.c
+++ b/sys/scsi/scsiconf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: scsiconf.c,v 1.97 2005/10/10 20:06:12 krw Exp $	*/
+/*	$OpenBSD: scsiconf.c,v 1.98 2005/11/13 03:27:42 krw Exp $	*/
 /*	$NetBSD: scsiconf.c,v 1.57 1996/05/02 01:09:01 neil Exp $	*/
 
 /*
@@ -179,15 +179,6 @@ scsibusattach(parent, self, aux)
 		bzero(sb->sc_link[i], nbytes);
 	}
 
-#if defined(SCSI_DELAY) && SCSI_DELAY > 2
-	printf("%s: waiting for scsi devices to settle\n",
-		sb->sc_dev.dv_xname);
-#else	/* SCSI_DELAY > 2 */
-#undef	SCSI_DELAY
-#define SCSI_DELAY 2
-#endif	/* SCSI_DELAY */
-	delay(1000000 * SCSI_DELAY);
-
 	scsi_probe_bus(sb->sc_dev.dv_unit, -1, -1);
 }