After extensive QA cycles at 3ware, bring the driver in-line with all the

issues which they found and asked to be changed so 3ware can offcially
support the driver.

Summary of the most significant changes:

- TWE_OVERRIDE is no longer supported
- If twe_getparam failed, bogus data would be returned to the caller
- Cache the device unit in the twe_drive structure to aid debugging
- Add the 3ware driver version.
- Proper return error codes for many functions.
- Track the minimum queue length statistics
- 4.x compat: use the cached unit number from the twe_drive structure
  instead of the the cached si_drv2.  3ware found that after many loads
  and unloads that si_drv2 became corrupted.  This did not happen in
  -current.

Submitted by:	Vinod Kashyap (with modifications by me)
Approved by:	re (rwatson)

7 files changed, 184 insertions, 158 deletions

diff --git a/sys/dev/twe/twe.c b/sys/dev/twe/twe.c
index 1ffb7b2..32cc61d 100644
--- a/sys/dev/twe/twe.c
+++ b/sys/dev/twe/twe.c
@@ -1,5 +1,7 @@
 /*-
  * Copyright (c) 2000 Michael Smith
+ * Copyright (c) 2003 Paul Saab
+ * Copyright (c) 2003 Vinod Kashyap
  * Copyright (c) 2000 BSDi
  * All rights reserved.
  *
@@ -60,8 +62,8 @@ static int	twe_wait_request(struct twe_request *tr);
 static int	twe_immediate_request(struct twe_request *tr);
 static void	twe_completeio(struct twe_request *tr);
 static void	twe_reset(struct twe_softc *sc);
-static void	twe_add_unit(struct twe_softc *sc, int unit);
-static void	twe_del_unit(struct twe_softc *sc, int unit);
+static int	twe_add_unit(struct twe_softc *sc, int unit);
+static int	twe_del_unit(struct twe_softc *sc, int unit);
 
 /*
  * Command I/O to controller.
@@ -86,7 +88,7 @@ static void	twe_command_intr(struct twe_softc *sc);
 static int	twe_fetch_aen(struct twe_softc *sc);
 static void	twe_handle_aen(struct twe_request *tr);
 static void	twe_enqueue_aen(struct twe_softc *sc, u_int16_t aen);
-static int	twe_dequeue_aen(struct twe_softc *sc);
+static u_int16_t	twe_dequeue_aen(struct twe_softc *sc);
 static int	twe_drain_aen_queue(struct twe_softc *sc);
 static int	twe_find_aen(struct twe_softc *sc, u_int16_t aen);
 
@@ -192,17 +194,17 @@ twe_setup(struct twe_softc *sc)
     return(0);
 }
 
-static void
+static int
 twe_add_unit(struct twe_softc *sc, int unit)
 {
     struct twe_drive		*dr;
-    int				table;
+    int				table, error = 0;
     u_int16_t			dsize;
     TWE_Param			*drives = NULL, *param = NULL;
     TWE_Unit_Descriptor		*ud;
 
     if (unit < 0 || unit > TWE_MAX_UNITS)
-	return;
+	return (EINVAL);
 
     /*
      * The controller is in a safe state, so try to find drives attached to it.
@@ -210,30 +212,36 @@ twe_add_unit(struct twe_softc *sc, int unit)
     if ((drives = twe_get_param(sc, TWE_PARAM_UNITSUMMARY, TWE_PARAM_UNITSUMMARY_Status,
 				TWE_MAX_UNITS, NULL)) == NULL) {
 	twe_printf(sc, "can't detect attached units\n");
-	return;
+	return (EIO);
     }
 
     dr = &sc->twe_drive[unit];
     /* check that the drive is online */
-    if (!(drives->data[unit] & TWE_PARAM_UNITSTATUS_Online))
+    if (!(drives->data[unit] & TWE_PARAM_UNITSTATUS_Online)) {
+	error = ENXIO;
 	goto out;
+    }
 
     table = TWE_PARAM_UNITINFO + unit;
 
     if (twe_get_param_4(sc, table, TWE_PARAM_UNITINFO_Capacity, &dr->td_size)) {
 	twe_printf(sc, "error fetching capacity for unit %d\n", unit);
+	error = EIO;
 	goto out;
     }
     if (twe_get_param_1(sc, table, TWE_PARAM_UNITINFO_Status, &dr->td_state)) {
 	twe_printf(sc, "error fetching state for unit %d\n", unit);
+	error = EIO;
 	goto out;
     }
     if (twe_get_param_2(sc, table, TWE_PARAM_UNITINFO_DescriptorSize, &dsize)) {
 	twe_printf(sc, "error fetching descriptor size for unit %d\n", unit);
+	error = EIO;
 	goto out;
     }
     if ((param = twe_get_param(sc, table, TWE_PARAM_UNITINFO_Descriptor, dsize - 3, NULL)) == NULL) {
 	twe_printf(sc, "error fetching descriptor for unit %d\n", unit);
+	error = EIO;
 	goto out;
     }
     ud = (TWE_Unit_Descriptor *)param->data;
@@ -248,25 +256,31 @@ twe_add_unit(struct twe_softc *sc, int unit)
 	dr->td_sectors = 32;
     }
     dr->td_cylinders = dr->td_size / (dr->td_heads * dr->td_sectors);
-    dr->td_unit = unit;
+    dr->td_twe_unit = unit;
 
-    twe_attach_drive(sc, dr);
+    error = twe_attach_drive(sc, dr);
 
 out:
     if (param != NULL)
 	free(param, M_DEVBUF);
     if (drives != NULL)
 	free(drives, M_DEVBUF);
+    return (error);
 }
 
-static void
+static int
 twe_del_unit(struct twe_softc *sc, int unit)
 {
+    int error;
 
     if (unit < 0 || unit > TWE_MAX_UNITS)
-	return;
+	return (ENXIO);
 
-    twe_detach_drive(sc, unit);
+    if (sc->twe_drive[unit].td_disk == NULL)
+	return (ENXIO);
+
+    error = twe_detach_drive(sc, unit);
+    return (error);
 }
 
 /********************************************************************************
@@ -477,7 +491,7 @@ twe_ioctl(struct twe_softc *sc, int ioctlcmd, void *addr)
     TWE_Param			*param;
     TWE_Command			*cmd;
     void			*data;
-    int				*arg = (int *)addr;
+    u_int16_t			*aen_code = (u_int16_t *)addr;
     struct twe_request		*tr;
     u_int8_t			srid;
     int				s, error;
@@ -553,13 +567,13 @@ twe_ioctl(struct twe_softc *sc, int ioctlcmd, void *addr)
 
 	/* poll for an AEN */
     case TWEIO_AEN_POLL:
-	*arg = twe_dequeue_aen(sc);
+	*aen_code = twe_dequeue_aen(sc);
 	break;
 
 	/* wait for another AEN to show up */
     case TWEIO_AEN_WAIT:
 	s = splbio();
-	while ((*arg = twe_dequeue_aen(sc)) == TWE_AEN_QUEUE_EMPTY) {
+	while ((*aen_code = twe_dequeue_aen(sc)) == TWE_AEN_QUEUE_EMPTY) {
 	    error = tsleep(&sc->twe_aen_queue, PRIBIO | PCATCH, "tweaen", 0);
 	    if (error == EINTR)
 		break;
@@ -600,11 +614,11 @@ twe_ioctl(struct twe_softc *sc, int ioctlcmd, void *addr)
 	break;
 
     case TWEIO_ADD_UNIT:
-	twe_add_unit(sc, td->td_unit);
+	error = twe_add_unit(sc, td->td_unit);
 	break;
 
     case TWEIO_DEL_UNIT:
-	twe_del_unit(sc, td->td_unit);
+	error = twe_del_unit(sc, td->td_unit);
 	break;
 
 	/* XXX implement ATA PASSTHROUGH */
@@ -735,6 +749,8 @@ twe_get_param(struct twe_softc *sc, int table_id, int param_id, size_t param_siz
 	if (error == 0) {
 	    if (twe_report_request(tr))
 		goto err;
+	} else {
+	    goto err;
 	}
 	twe_release_request(tr);
 	return(param);
@@ -924,6 +940,7 @@ twe_immediate_request(struct twe_request *tr)
 static void
 twe_completeio(struct twe_request *tr)
 {
+    TWE_Command		*cmd = TWE_FIND_COMMAND(tr);
     struct twe_softc	*sc = tr->tr_sc;
     twe_bio		*bp = (twe_bio *)tr->tr_private;
 
@@ -931,8 +948,9 @@ twe_completeio(struct twe_request *tr)
 
     if (tr->tr_status == TWE_CMD_COMPLETE) {
 
-	if (twe_report_request(tr))
-	    TWE_BIO_SET_ERROR(bp, EIO);
+	if (cmd->generic.status)
+	    if (twe_report_request(tr))
+		TWE_BIO_SET_ERROR(bp, EIO);
 
     } else {
 	twe_panic(sc, "twe_completeio on incomplete command");
@@ -1299,7 +1317,6 @@ twe_command_intr(struct twe_softc *sc)
      * them, and when other commands have completed.  Mask it so we don't get
      * another one.
      */
-    twe_printf(sc, "command interrupt\n");
     TWE_CONTROL(sc, TWE_CONTROL_MASK_COMMAND_INTERRUPT);
 }
 
@@ -1416,10 +1433,10 @@ twe_enqueue_aen(struct twe_softc *sc, u_int16_t aen)
  *
  * We are more or less interrupt-safe, so don't block interrupts.
  */
-static int
+static u_int16_t
 twe_dequeue_aen(struct twe_softc *sc)
 {
-    int		result;
+    u_int16_t	result;
     
     debug_called(4);
 
@@ -1556,23 +1573,33 @@ twe_describe_controller(struct twe_softc *sc)
     twe_get_param_1(sc, TWE_PARAM_CONTROLLER, TWE_PARAM_CONTROLLER_PortCount, &ports);
 
     /* get version strings */
-    p[0] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_Mon,  16, NULL);
-    p[1] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_FW,   16, NULL);
-    p[2] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_BIOS, 16, NULL);
-    p[3] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_PCB,  8, NULL);
-    p[4] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_ATA,  8, NULL);
-    p[5] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_PCI,  8, NULL);
-
-    twe_printf(sc, "%d ports, Firmware %.16s, BIOS %.16s\n", ports, p[1]->data, p[2]->data);
-    if (bootverbose)
-	twe_printf(sc, "Monitor %.16s, PCB %.8s, Achip %.8s, Pchip %.8s\n", p[0]->data, p[3]->data,
-		   p[4]->data, p[5]->data);
-    free(p[0], M_DEVBUF);
-    free(p[1], M_DEVBUF);
-    free(p[2], M_DEVBUF);
-    free(p[3], M_DEVBUF);
-    free(p[4], M_DEVBUF);
-    free(p[5], M_DEVBUF);
+    p[0] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_FW,   16, NULL);
+    p[1] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_BIOS, 16, NULL);
+    if (p[0] && p[1])
+	 twe_printf(sc, "%d ports, Firmware %.16s, BIOS %.16s\n", ports, p[0]->data, p[1]->data);
+
+    if (bootverbose) {
+	p[2] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_Mon,  16, NULL);
+	p[3] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_PCB,  8, NULL);
+	p[4] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_ATA,  8, NULL);
+	p[5] = twe_get_param(sc, TWE_PARAM_VERSION, TWE_PARAM_VERSION_PCI,  8, NULL);
+
+	if (p[2] && p[3] && p[4] && p[5])
+	    twe_printf(sc, "Monitor %.16s, PCB %.8s, Achip %.8s, Pchip %.8s\n", p[2]->data, p[3]->data,
+		p[4]->data, p[5]->data);
+	if (p[2])
+	    free(p[2], M_DEVBUF);
+	if (p[3])
+	    free(p[3], M_DEVBUF);
+	if (p[4])
+	    free(p[4], M_DEVBUF);
+	if (p[5])
+	    free(p[5], M_DEVBUF);
+    }
+    if (p[0])
+	free(p[0], M_DEVBUF);
+    if (p[1])
+	free(p[1], M_DEVBUF);
 
     /* print attached drives */
     if (bootverbose) {
@@ -1589,11 +1616,26 @@ twe_describe_controller(struct twe_softc *sc)
 		twe_printf(sc, "port %d, drive status unavailable\n", i);
 	    }
 	}
-	free(p[0], M_DEVBUF);
+	if (p[0])
+	    free(p[0], M_DEVBUF);
     }
 }
 
 /********************************************************************************
+ * Look up a text description of a numeric code and return a pointer to same.
+ */
+char *
+twe_describe_code(struct twe_code_lookup *table, u_int32_t code)
+{
+    int         i;
+
+    for (i = 0; table[i].string != NULL; i++)
+	if (table[i].code == code)
+	    return(table[i].string);
+    return(table[i+1].string);
+}
+
+/********************************************************************************
  * Complain if the status bits aren't what we're expecting.
  *
  * Rate-limit the complaints to at most one of each every five seconds, but
@@ -1714,7 +1756,7 @@ twe_report_request(struct twe_request *tr)
 	/*
 	 * The status code 0xff requests a controller reset.
 	 */
-	twe_printf(sc, "command returned with controller rest request\n");
+	twe_printf(sc, "command returned with controller reset request\n");
 	twe_reset(sc);
 	result = 1;
     } else if (cmd->generic.status > TWE_STATUS_FATAL) {
@@ -1770,12 +1812,22 @@ twe_print_controller(struct twe_softc *sc)
 
     status_reg = TWE_STATUS(sc);
     twe_printf(sc, "status   %b\n", status_reg, TWE_STATUS_BITS_DESCRIPTION);
-    twe_printf(sc, "          current  max\n");
-    twe_printf(sc, "free      %04d     %04d\n", sc->twe_qstat[TWEQ_FREE].q_length, sc->twe_qstat[TWEQ_FREE].q_max);
-    twe_printf(sc, "ready     %04d     %04d\n", sc->twe_qstat[TWEQ_READY].q_length, sc->twe_qstat[TWEQ_READY].q_max);
-    twe_printf(sc, "busy      %04d     %04d\n", sc->twe_qstat[TWEQ_BUSY].q_length, sc->twe_qstat[TWEQ_BUSY].q_max);
-    twe_printf(sc, "complete  %04d     %04d\n", sc->twe_qstat[TWEQ_COMPLETE].q_length, sc->twe_qstat[TWEQ_COMPLETE].q_max);
-    twe_printf(sc, "bioq      %04d     %04d\n", sc->twe_qstat[TWEQ_BIO].q_length, sc->twe_qstat[TWEQ_BIO].q_max);
+    twe_printf(sc, "          current  max    min\n");
+    twe_printf(sc, "free      %04d     %04d   %04d\n",
+	sc->twe_qstat[TWEQ_FREE].q_length, sc->twe_qstat[TWEQ_FREE].q_max, sc->twe_qstat[TWEQ_FREE].q_min);
+
+    twe_printf(sc, "ready     %04d     %04d   %04d\n",
+	sc->twe_qstat[TWEQ_READY].q_length, sc->twe_qstat[TWEQ_READY].q_max, sc->twe_qstat[TWEQ_READY].q_min);
+
+    twe_printf(sc, "busy      %04d     %04d   %04d\n",
+	sc->twe_qstat[TWEQ_BUSY].q_length, sc->twe_qstat[TWEQ_BUSY].q_max, sc->twe_qstat[TWEQ_BUSY].q_min);
+
+    twe_printf(sc, "complete  %04d     %04d   %04d\n",
+	sc->twe_qstat[TWEQ_COMPLETE].q_length, sc->twe_qstat[TWEQ_COMPLETE].q_max, sc->twe_qstat[TWEQ_COMPLETE].q_min);
+
+    twe_printf(sc, "bioq      %04d     %04d   %04d\n",
+	sc->twe_qstat[TWEQ_BIO].q_length, sc->twe_qstat[TWEQ_BIO].q_max, sc->twe_qstat[TWEQ_BIO].q_min);
+
     twe_printf(sc, "AEN queue head %d  tail %d\n", sc->twe_aen_head, sc->twe_aen_tail);
 }	
 
diff --git a/sys/dev/twe/twe_compat.h b/sys/dev/twe/twe_compat.h
index 981199a..78922a6 100644
--- a/sys/dev/twe/twe_compat.h
+++ b/sys/dev/twe/twe_compat.h
@@ -1,5 +1,7 @@
 /*-
  * Copyright (c) 2000 Michael Smith
+ * Copyright (c) 2003 Paul Saab
+ * Copyright (c) 2003 Vinod Kashyap
  * Copyright (c) 2000 BSDi
  * All rights reserved.
  *
@@ -56,43 +58,9 @@
 #include <dev/pci/pcireg.h>
 #include <dev/pci/pcivar.h>
 
-/*
- * These macros allows us to build a version of the driver which can 
- * safely be loaded into a kernel which already contains a 'twe' driver,
- * and which will override it in all things.
- *
- * All public symbols must be listed here.
- */
-#ifdef TWE_OVERRIDE
-#define twe_setup		Xtwe_setup
-#define twe_init		Xtwe_init
-#define twe_deinit		Xtwe_deinit
-#define twe_intr		Xtwe_intr
-#define twe_submit_bio		Xtwe_submit_bio
-#define twe_ioctl		Xtwe_ioctl
-#define twe_describe_controller	Xtwe_describe_controller
-#define twe_print_controller	Xtwe_print_controller
-#define twe_enable_interrupts	Xtwe_enable_interrupts
-#define twe_disable_interrupts	Xtwe_disable_interrupts
-#define twe_attach_drive	Xtwe_attach_drive
-#define twed_intr		Xtwed_intr
-#define twe_allocate_request	Xtwe_allocate_request
-#define twe_free_request	Xtwe_free_request
-#define twe_map_request		Xtwe_map_request
-#define twe_unmap_request	Xtwe_unmap_request
-#define twe_describe_code	Xtwe_describe_code
-#define twe_table_status	Xtwe_table_status
-#define twe_table_unitstate	Xtwe_table_unitstate
-#define twe_table_unittype	Xtwe_table_unittype
-#define twe_table_aen		Xtwe_table_aen
-#define TWE_DRIVER_NAME		Xtwe
-#define TWED_DRIVER_NAME	Xtwed
-#define TWE_MALLOC_CLASS	M_XTWE
-#else
 #define TWE_DRIVER_NAME		twe
 #define TWED_DRIVER_NAME	twed
 #define TWE_MALLOC_CLASS	M_TWE
-#endif
 
 /* 
  * Wrappers for bus-space actions
@@ -142,6 +110,7 @@
 #if __FreeBSD_version < 500003
 # include <machine/clock.h>
 # define INTR_ENTROPY			0
+# define FREEBSD_4
 
 # include <sys/buf.h>			/* old buf style */
 typedef struct buf			twe_bio;
@@ -164,6 +133,7 @@ typedef struct buf_queue_head		twe_bioq;
 # define TWE_BIO_STATS_END(bp)		devstat_end_transaction_buf(&((struct twed_softc *)TWE_BIO_SOFTC(bp))->twed_stats, bp)
 #else
 # include <sys/bio.h>
+# include <geom/geom_disk.h>
 typedef struct bio			twe_bio;
 typedef struct bio_queue_head		twe_bioq;
 # define TWE_BIO_QINIT(bq)		bioq_init(&bq);
diff --git a/sys/dev/twe/twe_freebsd.c b/sys/dev/twe/twe_freebsd.c
index c7c313f..34e4954 100644
--- a/sys/dev/twe/twe_freebsd.c
+++ b/sys/dev/twe/twe_freebsd.c
@@ -1,5 +1,7 @@
 /*-
  * Copyright (c) 2000 Michael Smith
+ * Copyright (c) 2003 Paul Saab
+ * Copyright (c) 2003 Vinod Kashyap
  * Copyright (c) 2000 BSDi
  * All rights reserved.
  *
@@ -31,20 +33,14 @@
  * FreeBSD-specific code.
  */
 
-#include <sys/param.h>
-#include <sys/cons.h>
-#include <machine/bus.h>
-#include <machine/clock.h>
-#include <machine/md_var.h>
-#include <vm/vm.h>
-#include <vm/pmap.h>
 #include <dev/twe/twe_compat.h>
-#include <geom/geom_disk.h>
 #include <dev/twe/twereg.h>
 #include <dev/twe/tweio.h>
 #include <dev/twe/twevar.h>
 #include <dev/twe/twe_tables.h>
 
+#include <vm/vm.h>
+
 static devclass_t	twe_devclass;
 
 #ifdef TWE_DEBUG
@@ -70,8 +66,6 @@ static	d_open_t		twe_open;
 static	d_close_t		twe_close;
 static	d_ioctl_t		twe_ioctl_wrapper;
 
-#define TWE_CDEV_MAJOR  146
-
 static struct cdevsw twe_cdevsw = {
 	.d_open =	twe_open,
 	.d_close =	twe_close,
@@ -127,7 +121,7 @@ static int	twe_probe(device_t dev);
 static int	twe_attach(device_t dev);
 static void	twe_free(struct twe_softc *sc);
 static int	twe_detach(device_t dev);
-static void	twe_shutdown(device_t dev);
+static int	twe_shutdown(device_t dev);
 static int	twe_suspend(device_t dev);
 static int	twe_resume(device_t dev);
 static void	twe_pci_intr(void *arg);
@@ -153,11 +147,7 @@ static driver_t twe_pci_driver = {
 	sizeof(struct twe_softc)
 };
 
-#ifdef TWE_OVERRIDE
-DRIVER_MODULE(Xtwe, pci, twe_pci_driver, twe_devclass, 0, 0);
-#else
 DRIVER_MODULE(twe, pci, twe_pci_driver, twe_devclass, 0, 0);
-#endif
 
 /********************************************************************************
  * Match a 3ware Escalade ATA RAID controller.
@@ -171,12 +161,8 @@ twe_probe(device_t dev)
     if ((pci_get_vendor(dev) == TWE_VENDOR_ID) &&
 	((pci_get_device(dev) == TWE_DEVICE_ID) || 
 	 (pci_get_device(dev) == TWE_DEVICE_ID_ASIC))) {
-	device_set_desc(dev, TWE_DEVICE_NAME);
-#ifdef TWE_OVERRIDE
+	device_set_desc_copy(dev, TWE_DEVICE_NAME ". Driver version " TWE_DRIVER_VERSION_STRING);
 	return(0);
-#else
-	return(-10);
-#endif
     }
     return(ENXIO);
 }
@@ -208,7 +194,7 @@ twe_attach(device_t dev)
 	return (ENXIO);
     }
     SYSCTL_ADD_STRING(&sc->sysctl_ctx, SYSCTL_CHILDREN(sc->sysctl_tree),
-	OID_AUTO, "driver_version", CTLFLAG_RD, "$Revision$", 0,
+	OID_AUTO, "driver_version", CTLFLAG_RD, TWE_DRIVER_VERSION_STRING, 0,
 	"TWE driver version");
 
     /*
@@ -459,7 +445,8 @@ twe_detach(device_t dev)
     /*	
      * Shut the controller down.
      */
-    twe_shutdown(dev);
+    if (twe_shutdown(dev))
+	goto out;
 
     twe_free(sc);
 
@@ -475,11 +462,11 @@ twe_detach(device_t dev)
  * Note that we can assume that the bioq on the controller is empty, as we won't
  * allow shutdown if any device is open.
  */
-static void
+static int
 twe_shutdown(device_t dev)
 {
     struct twe_softc	*sc = device_get_softc(dev);
-    int			i, s;
+    int			i, s, error = 0;
 
     debug_called(4);
 
@@ -489,7 +476,10 @@ twe_shutdown(device_t dev)
      * Delete all our child devices.
      */
     for (i = 0; i < TWE_MAX_UNITS; i++) {
-	twe_detach_drive(sc, i);
+	if (sc->twe_drive[i].td_disk != 0) {
+	    if ((error = twe_detach_drive(sc, i)) != 0)
+		goto out;
+	}
     }
 
     /*
@@ -497,7 +487,9 @@ twe_shutdown(device_t dev)
      */
     twe_deinit(sc);
 
+out:
     splx(s);
+    return(error);
 }
 
 /********************************************************************************
@@ -564,9 +556,9 @@ twe_intrhook(void *arg)
 /********************************************************************************
  * Given a detected drive, attach it to the bio interface.
  *
- * This is called from twe_init.
+ * This is called from twe_add_unit.
  */
-void
+int
 twe_attach_drive(struct twe_softc *sc, struct twe_drive *dr)
 {
     char	buf[80];
@@ -574,8 +566,8 @@ twe_attach_drive(struct twe_softc *sc, struct twe_drive *dr)
 
     dr->td_disk =  device_add_child(sc->twe_dev, NULL, -1);
     if (dr->td_disk == NULL) {
-	twe_printf(sc, "device_add_child failed\n");
-	return;
+	twe_printf(sc, "Cannot add unit\n");
+	return (EIO);
     }
     device_set_ivars(dr->td_disk, dr);
 
@@ -584,13 +576,16 @@ twe_attach_drive(struct twe_softc *sc, struct twe_drive *dr)
      * always set...
      */
     sprintf(buf, "Unit %d, %s, %s",
-	    dr->td_unit,
+	    dr->td_twe_unit,
 	    twe_describe_code(twe_table_unittype, dr->td_type),
 	    twe_describe_code(twe_table_unitstate, dr->td_state & TWE_PARAM_UNITSTATUS_MASK));
     device_set_desc_copy(dr->td_disk, buf);
 
-    if ((error = bus_generic_attach(sc->twe_dev)) != 0)
-	twe_printf(sc, "bus_generic_attach returned %d\n", error);
+    if ((error = bus_generic_attach(sc->twe_dev)) != 0) {
+	twe_printf(sc, "Cannot attach unit to controller. error = %d\n", error);
+	return (EIO);
+    }
+    return (0);
 }
 
 /********************************************************************************
@@ -598,15 +593,17 @@ twe_attach_drive(struct twe_softc *sc, struct twe_drive *dr)
  *
  * This is called from twe_del_unit.
  */
-void
+int
 twe_detach_drive(struct twe_softc *sc, int unit)
 {
+    int error = 0;
 
-    if (sc->twe_drive[unit].td_disk != 0) {
-	if (device_delete_child(sc->twe_dev, sc->twe_drive[unit].td_disk) != 0)
-	    twe_printf(sc, "failed to delete unit %d\n", unit);
-	sc->twe_drive[unit].td_disk = 0;
+    if ((error = device_delete_child(sc->twe_dev, sc->twe_drive[unit].td_disk)) != 0) {
+	twe_printf(sc, "failed to delete unit %d\n", unit);
+	return(error);
     }
+    bzero(&sc->twe_drive[unit], sizeof(sc->twe_drive[unit]));
+    return(error);
 }
 
 /********************************************************************************
@@ -638,7 +635,7 @@ twe_clear_pci_abort(struct twe_softc *sc)
 /*
  * Disk device softc
  */
-struct twed_softc 
+struct twed_softc
 {
     device_t		twed_dev;
     struct twe_softc	*twed_controller;	/* parent device softc */
@@ -667,11 +664,7 @@ static driver_t twed_driver = {
 };
 
 static devclass_t	twed_devclass;
-#ifdef TWE_OVERRIDE
-DRIVER_MODULE(Xtwed, Xtwe, twed_driver, twed_devclass, 0, 0);
-#else
 DRIVER_MODULE(twed, twe, twed_driver, twed_devclass, 0, 0);
-#endif
 
 /*
  * Disk device control interface.
@@ -714,11 +707,11 @@ twed_strategy(twe_bio *bp)
 
     debug_called(4);
 
-    bp->bio_driver1 = &sc->twed_drive->td_unit;
+    bp->bio_driver1 = &sc->twed_drive->td_twe_unit;
     TWED_BIO_IN;
 
     /* bogus disk? */
-    if (sc == NULL) {
+    if (sc == NULL || sc->twed_drive->td_disk == NULL) {
 	TWE_BIO_SET_ERROR(bp, EINVAL);
 	printf("twe: bio for invalid disk!\n");
 	TWE_BIO_DONE(bp);
@@ -755,7 +748,7 @@ twed_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset, size_t l
 	return(ENXIO);
 
     if (length > 0) {
-	if ((error = twe_dump_blocks(twe_sc, twed_sc->twed_drive->td_unit, offset / TWE_BLOCK_SIZE, virtual, length / TWE_BLOCK_SIZE)) != 0)
+	if ((error = twe_dump_blocks(twe_sc, twed_sc->twed_drive->td_twe_unit, offset / TWE_BLOCK_SIZE, virtual, length / TWE_BLOCK_SIZE)) != 0)
 	    return(error);
     }
     return(0);
@@ -822,8 +815,9 @@ twed_attach(device_t dev)
     sc->twed_disk.d_mediasize = TWE_BLOCK_SIZE * (off_t)sc->twed_drive->td_size;
     sc->twed_disk.d_fwsectors = sc->twed_drive->td_sectors;
     sc->twed_disk.d_fwheads = sc->twed_drive->td_heads;
+    sc->twed_drive->td_sys_unit = device_get_unit(dev);
 
-    disk_create(device_get_unit(dev), &sc->twed_disk, 0, NULL, NULL);
+    disk_create(sc->twed_drive->td_sys_unit, &sc->twed_disk, 0, NULL, NULL);
 #ifdef FREEBSD_4
     disks_registered++;
 #endif
@@ -846,13 +840,12 @@ twed_detach(device_t dev)
     if (sc->twed_disk.d_flags & DISKFLAG_OPEN)
 	return(EBUSY);
 
+    disk_destroy(&sc->twed_disk);
+
 #ifdef FREEBSD_4
     if (--disks_registered == 0)
 	cdevsw_remove(&tweddisk_cdevsw);
-#else
-    disk_destroy(&sc->twed_disk);
 #endif
-
     return(0);
 }
 
diff --git a/sys/dev/twe/twe_tables.h b/sys/dev/twe/twe_tables.h
index 4c0d719..3ba83c9 100644
--- a/sys/dev/twe/twe_tables.h
+++ b/sys/dev/twe/twe_tables.h
@@ -1,5 +1,7 @@
 /*-
  * Copyright (c) 2000 Michael Smith
+ * Copyright (c) 2003 Paul Saab
+ * Copyright (c) 2003 Vinod Kashyap
  * Copyright (c) 2000 BSDi
  * All rights reserved.
  *
@@ -45,21 +47,6 @@ extern struct twe_code_lookup twe_table_aen[];
 extern struct twe_code_lookup twe_table_opcode[];
 #else /* TWE_DEFINE_TABLES */
 
-/********************************************************************************
- * Look up a text description of a numeric code and return a pointer to same.
- */
-char *
-twe_describe_code(struct twe_code_lookup *table, u_int32_t code)
-{
-    int		i;
-
-    for (i = 0; table[i].string != NULL; i++)
-	if (table[i].code == code)
-	    return(table[i].string);
-    return(table[i+1].string);
-}
-
-
 struct twe_code_lookup twe_table_status[] = {
     /* success */
     {"successful completion",					0x00},
@@ -117,7 +104,7 @@ struct twe_code_lookup twe_table_unittype[] = {
 struct twe_code_lookup twe_table_aen[] = {
     {"q queue empty",			0x00},
     {"q soft reset",			0x01},
-    {"c degraded mirror",		0x02},
+    {"c degraded unit",			0x02},
     {"a controller error",		0x03},
     {"c rebuild fail",			0x04},
     {"c rebuild done",			0x05},
diff --git a/sys/dev/twe/tweio.h b/sys/dev/twe/tweio.h
index 7aed7d1..1b78472 100644
--- a/sys/dev/twe/tweio.h
+++ b/sys/dev/twe/tweio.h
@@ -1,5 +1,7 @@
 /*-
  * Copyright (c) 2000 Michael Smith
+ * Copyright (c) 2003 Paul Saab
+ * Copyright (c) 2003 Vinod Kashyap
  * Copyright (c) 2000 BSDi
  * All rights reserved.
  *
@@ -55,6 +57,7 @@ struct twe_usercommand {
 struct twe_qstat {
     u_int32_t	q_length;
     u_int32_t	q_max;
+    u_int32_t	q_min;
 };
 
 /*
@@ -70,8 +73,8 @@ union twe_statrequest {
 /*
  * AEN listen
  */
-#define TWEIO_AEN_POLL		_IOR('T', 102, int)
-#define TWEIO_AEN_WAIT		_IOR('T', 103, int)
+#define TWEIO_AEN_POLL		_IOR('T', 102, u_int16_t)
+#define TWEIO_AEN_WAIT		_IOR('T', 103, u_int16_t)
 
 /*
  * Controller parameter access
diff --git a/sys/dev/twe/twereg.h b/sys/dev/twe/twereg.h
index 705f419..5737b82 100644
--- a/sys/dev/twe/twereg.h
+++ b/sys/dev/twe/twereg.h
@@ -1,5 +1,7 @@
 /*-
  * Copyright (c) 2000 Michael Smith
+ * Copyright (c) 2003 Paul Saab
+ * Copyright (c) 2003 Vinod Kashyap
  * Copyright (c) 2000 BSDi
  * All rights reserved.
  *
@@ -98,7 +100,7 @@
 
 /* PCI related defines */
 #define TWE_IO_CONFIG_REG		0x10
-#define TWE_DEVICE_NAME			"3ware Storage Controller"
+#define TWE_DEVICE_NAME			"3ware 7000 series Storage Controller"
 #define TWE_VENDOR_ID			0x13C1
 #define TWE_DEVICE_ID			0x1000
 #define TWE_DEVICE_ID_ASIC		0x1001
@@ -280,6 +282,7 @@ typedef struct
     u_int8_t	unit:4;
     u_int8_t	host_id:4;
     u_int8_t	status;
+    u_int8_t	flags;
     u_int16_t	param;
     u_int16_t	features;
     u_int16_t	sector_count;
diff --git a/sys/dev/twe/twevar.h b/sys/dev/twe/twevar.h
index 22fb966..63700da 100644
--- a/sys/dev/twe/twevar.h
+++ b/sys/dev/twe/twevar.h
@@ -27,6 +27,14 @@
  *	$FreeBSD$
  */
 
+/*
+ * The scheme for the driver version is:
+ * <major change>.<external release>.<3ware internal release>.<development release>
+ */
+#define TWE_DRIVER_VERSION_STRING	"1.50.00.000"
+#define TWE_CDEV_MAJOR			146
+#define TWED_CDEV_MAJOR			147
+
 #ifdef TWE_DEBUG
 #define debug(level, fmt, args...)							\
 	do {										\
@@ -51,7 +59,8 @@ struct twe_drive
     int			td_cylinders;
     int			td_heads;
     int			td_sectors;
-    int			td_unit;
+    int			td_sys_unit; /* device unit number */
+    int			td_twe_unit; /* index into sc->twe_drive[] */
 
     /* unit state and type */
     u_int8_t		td_state;
@@ -151,9 +160,9 @@ extern void	twe_print_controller(struct twe_softc *sc);
 extern void	twe_enable_interrupts(struct twe_softc *sc);	/* enable controller interrupts */
 extern void	twe_disable_interrupts(struct twe_softc *sc);	/* disable controller interrupts */
 
-extern void	twe_attach_drive(struct twe_softc *sc,
+extern int	twe_attach_drive(struct twe_softc *sc,
 					 struct twe_drive *dr); /* attach drive when found in twe_init */
-extern void	twe_detach_drive(struct twe_softc *sc,
+extern int	twe_detach_drive(struct twe_softc *sc,
 					 int unit);		/* detach drive */
 extern void	twe_clear_pci_parity_error(struct twe_softc *sc);
 extern void	twe_clear_pci_abort(struct twe_softc *sc);
@@ -175,11 +184,20 @@ extern void	twe_unmap_request(struct twe_request *tr);	/* cleanup after transfer
 		qs->q_max = qs->q_length;			\
 	} while(0)
 
-#define TWEQ_REMOVE(sc, qname)    (sc)->twe_qstat[qname].q_length--
-#define TWEQ_INIT(sc, qname)			\
-	do {					\
-	    sc->twe_qstat[qname].q_length = 0;	\
-	    sc->twe_qstat[qname].q_max = 0;	\
+#define TWEQ_REMOVE(sc, qname)					\
+	do {							\
+	    struct twe_qstat *qs = &(sc)->twe_qstat[qname];	\
+								\
+	    qs->q_length--;					\
+	    if (qs->q_length < qs->q_min)			\
+		qs->q_min = qs->q_length;			\
+	} while(0);
+
+#define TWEQ_INIT(sc, qname)					\
+	do {							\
+	    sc->twe_qstat[qname].q_length = 0;			\
+	    sc->twe_qstat[qname].q_max = 0;			\
+	    sc->twe_qstat[qname].q_min = 0xFFFFFFFF;		\
 	} while(0)