diff --git a/sys/amd64/pci/pci_bus.c b/sys/amd64/pci/pci_bus.c
index 7085c1edbc77..b801abd16c90 100644
--- a/sys/amd64/pci/pci_bus.c
+++ b/sys/amd64/pci/pci_bus.c
@@ -23,7 +23,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $Id: pcibus.c,v 1.37 1997/05/26 21:11:05 se Exp $
+ * $Id: pcibus.c,v 1.38 1997/05/26 21:25:24 se Exp $
  *
  */
 
@@ -59,9 +59,10 @@ pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
 	    && (reg & (bytes -1)) == 0) {
 		switch (cfgmech) {
 		case 1:
-			outl(CONF1_ADDR_PORT, (1 << 31) |
-			     (bus << 16) | (slot << 11) | (func << 8) | reg);
-			dataport = CONF1_DATA_PORT;
+			outl(CONF1_ADDR_PORT, (1 << 31)
+			     | (bus << 16) | (slot << 11) 
+			     | (func << 8) | (reg & ~0x03));
+			dataport = CONF1_DATA_PORT + (reg & 0x03);
 			break;
 		case 2:
 			outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
diff --git a/sys/amd64/pci/pci_cfgreg.c b/sys/amd64/pci/pci_cfgreg.c
index 7085c1edbc77..b801abd16c90 100644
--- a/sys/amd64/pci/pci_cfgreg.c
+++ b/sys/amd64/pci/pci_cfgreg.c
@@ -23,7 +23,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $Id: pcibus.c,v 1.37 1997/05/26 21:11:05 se Exp $
+ * $Id: pcibus.c,v 1.38 1997/05/26 21:25:24 se Exp $
  *
  */
 
@@ -59,9 +59,10 @@ pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
 	    && (reg & (bytes -1)) == 0) {
 		switch (cfgmech) {
 		case 1:
-			outl(CONF1_ADDR_PORT, (1 << 31) |
-			     (bus << 16) | (slot << 11) | (func << 8) | reg);
-			dataport = CONF1_DATA_PORT;
+			outl(CONF1_ADDR_PORT, (1 << 31)
+			     | (bus << 16) | (slot << 11) 
+			     | (func << 8) | (reg & ~0x03));
+			dataport = CONF1_DATA_PORT + (reg & 0x03);
 			break;
 		case 2:
 			outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
diff --git a/sys/i386/isa/pcibus.c b/sys/i386/isa/pcibus.c
index 7085c1edbc77..b801abd16c90 100644
--- a/sys/i386/isa/pcibus.c
+++ b/sys/i386/isa/pcibus.c
@@ -23,7 +23,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $Id: pcibus.c,v 1.37 1997/05/26 21:11:05 se Exp $
+ * $Id: pcibus.c,v 1.38 1997/05/26 21:25:24 se Exp $
  *
  */
 
@@ -59,9 +59,10 @@ pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
 	    && (reg & (bytes -1)) == 0) {
 		switch (cfgmech) {
 		case 1:
-			outl(CONF1_ADDR_PORT, (1 << 31) |
-			     (bus << 16) | (slot << 11) | (func << 8) | reg);
-			dataport = CONF1_DATA_PORT;
+			outl(CONF1_ADDR_PORT, (1 << 31)
+			     | (bus << 16) | (slot << 11) 
+			     | (func << 8) | (reg & ~0x03));
+			dataport = CONF1_DATA_PORT + (reg & 0x03);
 			break;
 		case 2:
 			outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
diff --git a/sys/i386/pci/pci_bus.c b/sys/i386/pci/pci_bus.c
index 7085c1edbc77..b801abd16c90 100644
--- a/sys/i386/pci/pci_bus.c
+++ b/sys/i386/pci/pci_bus.c
@@ -23,7 +23,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $Id: pcibus.c,v 1.37 1997/05/26 21:11:05 se Exp $
+ * $Id: pcibus.c,v 1.38 1997/05/26 21:25:24 se Exp $
  *
  */
 
@@ -59,9 +59,10 @@ pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
 	    && (reg & (bytes -1)) == 0) {
 		switch (cfgmech) {
 		case 1:
-			outl(CONF1_ADDR_PORT, (1 << 31) |
-			     (bus << 16) | (slot << 11) | (func << 8) | reg);
-			dataport = CONF1_DATA_PORT;
+			outl(CONF1_ADDR_PORT, (1 << 31)
+			     | (bus << 16) | (slot << 11) 
+			     | (func << 8) | (reg & ~0x03));
+			dataport = CONF1_DATA_PORT + (reg & 0x03);
 			break;
 		case 2:
 			outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
diff --git a/sys/i386/pci/pci_cfgreg.c b/sys/i386/pci/pci_cfgreg.c
index 7085c1edbc77..b801abd16c90 100644
--- a/sys/i386/pci/pci_cfgreg.c
+++ b/sys/i386/pci/pci_cfgreg.c
@@ -23,7 +23,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $Id: pcibus.c,v 1.37 1997/05/26 21:11:05 se Exp $
+ * $Id: pcibus.c,v 1.38 1997/05/26 21:25:24 se Exp $
  *
  */
 
@@ -59,9 +59,10 @@ pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
 	    && (reg & (bytes -1)) == 0) {
 		switch (cfgmech) {
 		case 1:
-			outl(CONF1_ADDR_PORT, (1 << 31) |
-			     (bus << 16) | (slot << 11) | (func << 8) | reg);
-			dataport = CONF1_DATA_PORT;
+			outl(CONF1_ADDR_PORT, (1 << 31)
+			     | (bus << 16) | (slot << 11) 
+			     | (func << 8) | (reg & ~0x03));
+			dataport = CONF1_DATA_PORT + (reg & 0x03);
 			break;
 		case 2:
 			outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
diff --git a/sys/i386/pci/pci_pir.c b/sys/i386/pci/pci_pir.c
index 7085c1edbc77..b801abd16c90 100644
--- a/sys/i386/pci/pci_pir.c
+++ b/sys/i386/pci/pci_pir.c
@@ -23,7 +23,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $Id: pcibus.c,v 1.37 1997/05/26 21:11:05 se Exp $
+ * $Id: pcibus.c,v 1.38 1997/05/26 21:25:24 se Exp $
  *
  */
 
@@ -59,9 +59,10 @@ pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
 	    && (reg & (bytes -1)) == 0) {
 		switch (cfgmech) {
 		case 1:
-			outl(CONF1_ADDR_PORT, (1 << 31) |
-			     (bus << 16) | (slot << 11) | (func << 8) | reg);
-			dataport = CONF1_DATA_PORT;
+			outl(CONF1_ADDR_PORT, (1 << 31)
+			     | (bus << 16) | (slot << 11) 
+			     | (func << 8) | (reg & ~0x03));
+			dataport = CONF1_DATA_PORT + (reg & 0x03);
 			break;
 		case 2:
 			outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));