Make SCSI_DELAY setable at boot time and runtime via the

kern.cam.scsi_delay tunable/sysctl.

Reviewed by:	mdodd, njl

sys/boot/forth/loader.conf

@@ -90,6 +90,7 @@ module_path="/boot/kernel;/boot/modules;/modules"	# Set the module search path
 #kern.nbuf=""			# Set the number of buffer headers 
 #kern.ncallout=""		# Set the maximum # of timer events
 #kern.sgrowsiz=""		# Set the amount to grow stack
+#kern.cam.scsi_delay="2000"	# Delay (in ms) before probing SCSI
 #kern.ipc.maxsockets=""	# Set the maximum number of sockets avaliable
 #kern.ipc.nmbclusters=""	# Set the number of mbuf clusters
 #kern.ipc.nmbufs=""		# Set the maximum number of mbufs

sys/cam/cam_periph.c

@@ -1126,7 +1126,7 @@ cam_periph_async(struct cam_periph *periph, u_int32_t code,
 	case AC_SENT_BDR:
 	case AC_BUS_RESET:
 	{
-		cam_periph_bus_settle(periph, SCSI_DELAY);
+		cam_periph_bus_settle(periph, scsi_delay);
 		break;
 	}
 	default:

sys/cam/cam_xpt.c

@@ -5487,7 +5487,7 @@ proberegister(struct cam_periph *periph, void *arg)
 	 * For HBAs that don't do bus resets, this won't make a difference.
 	 */
 	cam_periph_freeze_after_event(periph, &periph->path->bus->last_reset,
-				      SCSI_DELAY);
+				      scsi_delay);
 	probeschedule(periph);
 	return(CAM_REQ_CMP);
 }
@@ -6760,9 +6760,9 @@ xpt_config(void *arg)
 		/* Call manually because we don't have any busses */
 		xpt_finishconfig(xpt_periph, NULL);
 	} else  {
-		if (busses_to_reset > 0 && SCSI_DELAY >= 2000) {
+		if (busses_to_reset > 0 && scsi_delay >= 2000) {
 			printf("Waiting %d seconds for SCSI "
-			       "devices to settle\n", SCSI_DELAY/1000);
+			       "devices to settle\n", scsi_delay/1000);
 		}
 		xpt_for_all_busses(xptconfigfunc, NULL);
 	}

sys/cam/scsi/scsi_all.c

@@ -36,6 +36,8 @@
 
 #include <sys/systm.h>
 #include <sys/libkern.h>
+#include <sys/kernel.h>
+#include <sys/sysctl.h>
 #else
 #include <errno.h>
 #include <stdio.h>
@@ -61,12 +63,40 @@
 #define EJUSTRETURN     -2              /* don't modify regs, just return */
 #endif /* !_KERNEL */
 
+/*
+ * This is the default number of seconds we wait for devices to settle
+ * after a SCSI bus reset.
+ */
+#ifndef SCSI_DELAY
+#define SCSI_DELAY 2000
+#endif
+/*
+ * All devices need _some_ sort of bus settle delay, so we'll set it to
+ * a minimum value of 100ms.
+ */
+#ifndef SCSI_MIN_DELAY
+#define SCSI_MIN_DELAY 100
+#endif
+/*
+ * Make sure the user isn't using seconds instead of milliseconds.
+ */
+#if (SCSI_DELAY < SCSI_MIN_DELAY)
+#error "SCSI_DELAY is in milliseconds, not seconds!  Please use a larger value"
+#endif
+
+int scsi_delay;
+
 static int	ascentrycomp(const void *key, const void *member);
 static int	senseentrycomp(const void *key, const void *member);
 static void	fetchtableentries(int sense_key, int asc, int ascq,
 				  struct scsi_inquiry_data *,
 				  const struct sense_key_table_entry **,
 				  const struct asc_table_entry **);
+#ifdef _KERNEL
+static void	init_scsi_delay(void);
+static int	sysctl_scsi_delay(SYSCTL_HANDLER_ARGS);
+static int	set_scsi_delay(int delay);
+#endif
 
 #if !defined(SCSI_NO_OP_STRINGS)
 
@@ -2876,3 +2906,53 @@ scsi_static_inquiry_match(caddr_t inqbuffer, caddr_t table_entry)
 	}
         return (-1);
 }
+
+#ifdef _KERNEL
+static void
+init_scsi_delay(void)
+{
+	int delay;
+
+	delay = SCSI_DELAY;
+	TUNABLE_INT_FETCH("kern.cam.scsi_delay", &delay);
+
+	if (set_scsi_delay(delay) != 0) {
+		printf("cam: invalid value for tunable kern.cam.scsi_delay\n");
+		set_scsi_delay(SCSI_DELAY);
+	}
+}
+SYSINIT(scsi_delay, SI_SUB_TUNABLES, SI_ORDER_ANY, init_scsi_delay, NULL);
+
+static int
+sysctl_scsi_delay(SYSCTL_HANDLER_ARGS)
+{
+	int error, delay;
+
+	delay = scsi_delay;
+	error = sysctl_handle_int(oidp, &delay, sizeof(delay), req);
+	if (error != 0 || req->newptr == NULL)
+		return (error);
+	return (set_scsi_delay(delay));
+}
+SYSCTL_PROC(_kern_cam, OID_AUTO, scsi_delay, CTLTYPE_INT|CTLFLAG_RW,
+    0, 0, sysctl_scsi_delay, "I",
+    "Delay to allow devices to settle after a SCSI bus reset (ms)");
+
+static int
+set_scsi_delay(int delay)
+{
+	/*
+         * If someone sets this to 0, we assume that they want the
+         * minimum allowable bus settle delay.
+	 */
+	if (delay == 0) {
+		printf("cam: using minimum scsi_delay (%dms)\n",
+		    SCSI_MIN_DELAY);
+		delay = SCSI_MIN_DELAY;
+	}
+	if (delay < SCSI_MIN_DELAY)
+		return (EINVAL);
+	scsi_delay = delay;
+	return (0);
+}
+#endif /* _KERNEL */

sys/cam/scsi/scsi_all.h

@@ -27,30 +27,11 @@
 #include <sys/cdefs.h>
 
 #ifdef _KERNEL
-#include "opt_scsi.h"
 /*
  * This is the number of seconds we wait for devices to settle after a SCSI
  * bus reset.
  */
-#ifndef SCSI_DELAY
-#define SCSI_DELAY 2000
-#endif
-/*
- * If someone sets this to 0, we assume that they want the minimum
- * allowable bus settle delay.  All devices need _some_ sort of bus settle
- * delay, so we'll set it to a minimum value of 100ms.
- */
-#if (SCSI_DELAY == 0)
-#undef SCSI_DELAY
-#define SCSI_DELAY 100
-#endif
-
-/*
- * Make sure the user isn't using seconds instead of milliseconds.
- */
-#if (SCSI_DELAY < 100)
-#error "SCSI_DELAY is in milliseconds, not seconds!  Please use a larger value"
-#endif
+extern int scsi_delay;
 #endif /* _KERNEL */
 
 /*

sys/conf/NOTES

@@ -871,7 +871,9 @@ device		pass		#CAM passthrough driver
 # SCSI_NO_OP_STRINGS: When defined disables opcode descriptions
 # SCSI_DELAY: The number of MILLISECONDS to freeze the SIM (scsi adapter)
 #             queue after a bus reset, and the number of milliseconds to
-#             freeze the device queue after a bus device reset.
+#             freeze the device queue after a bus device reset.  This
+#             can be changed at boot and runtime with the
+#             kern.cam.scsi_delay tunable/sysctl.
 options 	CAMDEBUG
 options 	CAM_DEBUG_BUS=-1
 options 	CAM_DEBUG_TARGET=-1