diff --git a/sys/dev/aic7xxx/ahd_pci.c b/sys/dev/aic7xxx/ahd_pci.c
index 6268d5b1967d..9549a4ae1c0d 100644
--- a/sys/dev/aic7xxx/ahd_pci.c
+++ b/sys/dev/aic7xxx/ahd_pci.c
@@ -28,7 +28,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: //depot/aic7xxx/freebsd/dev/aic7xxx/ahd_pci.c#9 $
+ * $Id: //depot/aic7xxx/freebsd/dev/aic7xxx/ahd_pci.c#10 $
  *
  * $FreeBSD$
  */
@@ -150,14 +150,26 @@ ahd_pci_map_registers(struct ahd_softc *ahd)
 	int	regs_type;
 	int	regs_id;
 	int	regs_id2;
+	int	allow_memio;
 
 	command = ahd_pci_read_config(ahd->dev_softc, PCIR_COMMAND, /*bytes*/1);
 	regs = NULL;
 	regs2 = NULL;
 	regs_type = 0;
 	regs_id = 0;
+
+	/* Retrieve the per-device 'allow_memio' hint */
+	if (resource_int_value(device_get_name(ahd->dev_softc),
+			       device_get_unit(ahd->dev_softc),
+			       "allow_memio", &allow_memio) != 0) {
+		if (bootverbose)
+			device_printf(ahd->dev_softc,
+				      "Defaulting to MEMIO on\n");
+	}
+
 	if ((command & PCIM_CMD_MEMEN) != 0
-	 && (ahd->bugs & AHD_PCIX_MMAPIO_BUG) == 0) {
+	 && (ahd->bugs & AHD_PCIX_MMAPIO_BUG) == 0
+	 && allow_memio != 0) {
 
 		regs_type = SYS_RES_MEMORY;
 		regs_id = AHD_PCI_MEMADDR;
diff --git a/sys/dev/aic7xxx/aic79xx.reg b/sys/dev/aic7xxx/aic79xx.reg
index 7611b9aa0d0b..9949d3b7a098 100644
--- a/sys/dev/aic7xxx/aic79xx.reg
+++ b/sys/dev/aic7xxx/aic79xx.reg
@@ -39,7 +39,7 @@
  *
  * $FreeBSD$
  */
-VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic79xx.reg#55 $"
+VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic79xx.reg#56 $"
 
 /*
  * This file is processed by the aic7xxx_asm utility for use in assembling
@@ -190,6 +190,7 @@ register CLRINT {
 	field	CLRHWERRINT	0x80 /* Rev B or greater */
 	field	CLRBRKADRINT	0x40
 	field	CLRSWTMINT	0x20
+	field	CLRPCIINT	0x10
 	field	CLRSCSIINT	0x08
 	field	CLRSEQINT	0x04
 	field	CLRCMDINT	0x02
@@ -1168,7 +1169,7 @@ register MSIPCISTAT {
  * PCI Status for Target
  */
 register TARGPCISTAT {
-	address			0x0A6
+	address			0x0A7
 	access_mode	RW
 	modes		M_CFG
 	field	DPE		0x80
diff --git a/sys/dev/aic7xxx/aic79xx_osm.h b/sys/dev/aic7xxx/aic79xx_osm.h
index 6379a02740b4..981398662581 100644
--- a/sys/dev/aic7xxx/aic79xx_osm.h
+++ b/sys/dev/aic7xxx/aic79xx_osm.h
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: //depot/aic7xxx/freebsd/dev/aic7xxx/aic79xx_osm.h#18 $
+ * $Id: //depot/aic7xxx/freebsd/dev/aic7xxx/aic79xx_osm.h#19 $
  *
  * $FreeBSD$
  */
@@ -239,8 +239,9 @@ ahd_timer_reset(ahd_timer_t *timer, u_int usec, ahd_callback_t *func, void *arg)
 static __inline void
 ahd_scb_timer_reset(struct scb *scb, u_int usec)
 {
-	callout_reset(scb->io_ctx->ccb_h.timeout_ch.callout,
-		      (usec * hz)/1000000, ahd_timeout, scb);
+	untimeout(ahd_timeout, (caddr_t)scb, scb->io_ctx->ccb_h.timeout_ch);
+	scb->io_ctx->ccb_h.timeout_ch =
+	    timeout(ahd_timeout, scb, (usec * hz)/1000000);
 }
 
 /*************************** Device Access ************************************/
diff --git a/sys/dev/aic7xxx/aic79xx_pci.c b/sys/dev/aic7xxx/aic79xx_pci.c
index fdbfc4574daf..7dd68a3746fd 100644
--- a/sys/dev/aic7xxx/aic79xx_pci.c
+++ b/sys/dev/aic7xxx/aic79xx_pci.c
@@ -38,7 +38,7 @@
  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGES.
  *
- * $Id: //depot/aic7xxx/aic7xxx/aic79xx_pci.c#54 $
+ * $Id: //depot/aic7xxx/aic7xxx/aic79xx_pci.c#60 $
  *
  * $FreeBSD$
  */
@@ -175,8 +175,8 @@ struct ahd_pci_identity ahd_pci_ident_table [] =
 	},
 	/* Generic chip probes for devices we don't know 'exactly' */
 	{
-		ID_AIC7901A & ID_ALL_MASK,
-		ID_ALL_MASK,
+		ID_AIC7901A & ID_DEV_VENDOR_MASK,
+		ID_DEV_VENDOR_MASK,
 		"Adaptec AIC7901A Ultra320 SCSI adapter",
 		ahd_aic7901A_setup
 	},
@@ -378,7 +378,16 @@ ahd_pci_config(struct ahd_softc *ahd, struct ahd_pci_identity *entry)
 int
 ahd_pci_test_register_access(struct ahd_softc *ahd)
 {
-	int i;
+	ahd_mode_state	saved_modes;
+	int		error;
+	uint8_t		seqctl;
+
+	saved_modes = ahd_save_modes(ahd);
+	error = EIO;
+
+	/* Enable PCI error interrupt status */
+	seqctl = ahd_inb(ahd, SEQCTL0);
+	ahd_outb(ahd, SEQCTL0, seqctl & ~FAILDIS);
 
 	/*
 	 * First a simple test to see if any
@@ -389,7 +398,7 @@ ahd_pci_test_register_access(struct ahd_softc *ahd)
 	 * use for this test.
 	 */
 	if (ahd_inb(ahd, HCNTRL) == 0xFF)
-		return (EIO);
+		goto fail;
 
 	/*
 	 * Next create a situation where write combining
@@ -398,19 +407,26 @@ ahd_pci_test_register_access(struct ahd_softc *ahd)
 	 * either, so look for data corruption and/or flaged
 	 * PCI errors.
 	 */
-	for (i = 0; i < 16; i++)
-	       ahd_outb(ahd, SRAM_BASE + i, i);
-
-	for (i = 0; i < 16; i++)
-		if (ahd_inb(ahd, SRAM_BASE + i) != i)
-			return (EIO);
+	ahd_outl(ahd, SRAM_BASE, 0x5aa555aa);
+	if (ahd_inl(ahd, SRAM_BASE) != 0x5aa555aa)
+		goto fail;
 
 	if ((ahd_inb(ahd, INTSTAT) & PCIINT) != 0) {
-		ahd_mode_state	saved_modes;
-		u_int		targpcistat;
-		u_int		pci_status1;
+		u_int targpcistat;
+
+		ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
+		targpcistat = ahd_inb(ahd, TARGPCISTAT);
+		if ((targpcistat & STA) != 0)
+			goto fail;
+	}
+
+	error = 0;
+
+fail:
+	if ((ahd_inb(ahd, INTSTAT) & PCIINT) != 0) {
+		u_int targpcistat;
+		u_int pci_status1;
 
-		saved_modes = ahd_save_modes(ahd);
 		ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
 		targpcistat = ahd_inb(ahd, TARGPCISTAT);
 
@@ -420,13 +436,12 @@ ahd_pci_test_register_access(struct ahd_softc *ahd)
 						  PCIR_STATUS + 1, /*bytes*/1);
 		ahd_pci_write_config(ahd->dev_softc, PCIR_STATUS + 1,
 				     pci_status1, /*bytes*/1);
-		ahd_restore_modes(ahd, saved_modes);
-
-		if ((targpcistat & STA) != 0)
-			return (EIO);
+		ahd_outb(ahd, CLRINT, CLRPCIINT);
 	}
 
-	return (0);
+	ahd_restore_modes(ahd, saved_modes);
+	ahd_outb(ahd, SEQCTL0, seqctl);
+	return (error);
 }
 
 /*
@@ -731,7 +746,7 @@ ahd_pci_intr(struct ahd_softc *ahd)
 
 				s = pci_status_strings[bit];
 				if (i == 7/*TARG*/ && bit == 3)
-					s = "%s: Signal Target Abort\n";
+					s = "%s: Signaled Target Abort\n";
 				printf(s, ahd_name(ahd), pci_status_source[i]);
 			}
 		}	
@@ -741,6 +756,7 @@ ahd_pci_intr(struct ahd_softc *ahd)
 	ahd_pci_write_config(ahd->dev_softc, PCIR_STATUS + 1,
 			     pci_status1, /*bytes*/1);
 	ahd_restore_modes(ahd, saved_modes);
+	ahd_outb(ahd, CLRINT, CLRPCIINT);
 	ahd_unpause(ahd);
 }
 
@@ -810,6 +826,7 @@ ahd_pci_split_intr(struct ahd_softc *ahd, u_int intstat)
 	 */
 	ahd_pci_write_config(ahd->dev_softc, PCIXR_STATUS,
 			     pcix_status, /*bytes*/2);
+	ahd_outb(ahd, CLRINT, CLRSPLTINT);
 	ahd_restore_modes(ahd, saved_modes);
 }
 
diff --git a/sys/dev/aic7xxx/aic7xxx_osm.h b/sys/dev/aic7xxx/aic7xxx_osm.h
index ff80362c8d28..a5bdc1830048 100644
--- a/sys/dev/aic7xxx/aic7xxx_osm.h
+++ b/sys/dev/aic7xxx/aic7xxx_osm.h
@@ -29,7 +29,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: //depot/aic7xxx/freebsd/dev/aic7xxx/aic7xxx_osm.h#13 $
+ * $Id: //depot/aic7xxx/freebsd/dev/aic7xxx/aic7xxx_osm.h#14 $
  *
  * $FreeBSD$
  */
@@ -251,8 +251,9 @@ ahc_timer_reset(ahc_timer_t *timer, u_int usec, ahc_callback_t *func, void *arg)
 static __inline void
 ahc_scb_timer_reset(struct scb *scb, u_int usec)
 {
-	callout_reset(scb->io_ctx->ccb_h.timeout_ch.callout,
-		      (usec * hz)/1000000, ahc_timeout, scb);
+	untimeout(ahc_timeout, (caddr_t)scb, scb->io_ctx->ccb_h.timeout_ch);
+	scb->io_ctx->ccb_h.timeout_ch =
+	    timeout(ahc_timeout, scb, (usec * hz)/1000000);
 }
 
 /*************************** Device Access ************************************/
diff --git a/sys/dev/aic7xxx/aic7xxx_pci.c b/sys/dev/aic7xxx/aic7xxx_pci.c
index 9b935959764a..959908d19d35 100644
--- a/sys/dev/aic7xxx/aic7xxx_pci.c
+++ b/sys/dev/aic7xxx/aic7xxx_pci.c
@@ -39,7 +39,7 @@
  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGES.
  *
- * $Id: //depot/aic7xxx/aic7xxx/aic7xxx_pci.c#52 $
+ * $Id: //depot/aic7xxx/aic7xxx/aic7xxx_pci.c#53 $
  *
  * $FreeBSD$
  */
@@ -1202,8 +1202,15 @@ ahc_probe_ext_scbram(struct ahc_softc *ahc)
 int
 ahc_pci_test_register_access(struct ahc_softc *ahc)
 {
-	int   i;
-	u_int status1;
+	int	error;
+	u_int	status1;
+	uint8_t	seqctl;
+
+	error = EIO;
+
+	/* Enable PCI error interrupt status */
+	seqctl = ahc_inb(ahc, SEQCTL);
+	ahc_outb(ahc, SEQCTL, seqctl & ~FAILDIS);
 
 	/*
 	 * First a simple test to see if any
@@ -1214,7 +1221,7 @@ ahc_pci_test_register_access(struct ahc_softc *ahc)
 	 * use for this test.
 	 */
 	if (ahc_inb(ahc, HCNTRL) == 0xFF)
-		return (EIO);
+		goto fail;
 
 	/*
 	 * Next create a situation where write combining
@@ -1223,25 +1230,33 @@ ahc_pci_test_register_access(struct ahc_softc *ahc)
 	 * either, so look for data corruption and/or flagged
 	 * PCI errors.
 	 */
-	for (i = 0; i < 16; i++)
-		ahc_outb(ahc, SRAM_BASE + i, i);
+	ahc_outb(ahc, SRAM_BASE, 0xaa);
+	ahc_outb(ahc, SRAM_BASE + 1, 0x55);
+	ahc_outb(ahc, SRAM_BASE + 2, 0xa5);
+	ahc_outb(ahc, SRAM_BASE + 3, 0x5a);
 
-	for (i = 0; i < 16; i++)
-		if (ahc_inb(ahc, SRAM_BASE + i) != i)
-			return (EIO);
+	if ((ahc_inb(ahc, SRAM_BASE) != 0xaa)
+	 || (ahc_inb(ahc, SRAM_BASE + 1) != 0x55)
+	 || (ahc_inb(ahc, SRAM_BASE + 2) != 0xa5)
+	 || (ahc_inb(ahc, SRAM_BASE + 3) != 0x5a))
+		goto fail;
 
 	status1 = ahc_pci_read_config(ahc->dev_softc,
 				      PCIR_STATUS + 1, /*bytes*/1);
-	if ((status1 & STA) != 0) {
+	if ((status1 & STA) != 0)
+		goto fail;
 
-		/* Silently clear any latched errors. */
-		ahc_pci_write_config(ahc->dev_softc, PCIR_STATUS + 1,
-				     status1, /*bytes*/1);
-		ahc_outb(ahc, CLRINT, CLRPARERR);
-		return (EIO);
-	}
+	error = 0;
 
-	return (0);
+fail:
+	/* Silently clear any latched errors. */
+	status1 = ahc_pci_read_config(ahc->dev_softc,
+				      PCIR_STATUS + 1, /*bytes*/1);
+	ahc_pci_write_config(ahc->dev_softc, PCIR_STATUS + 1,
+			     status1, /*bytes*/1);
+	ahc_outb(ahc, CLRINT, CLRPARERR);
+	ahc_outb(ahc, SEQCTL, seqctl);
+	return (error);
 }
 
 /*