diff --git a/sys/dev/ata/ata-all.c b/sys/dev/ata/ata-all.c
index fe87b766abf4..17fa2efa36e6 100644
--- a/sys/dev/ata/ata-all.c
+++ b/sys/dev/ata/ata-all.c
@@ -211,8 +211,8 @@ struct ata_pci_softc {
     int32_t irqcnt;
 };
 
-static int32_t
-ata_find_dev(device_t dev, int32_t type)
+int32_t
+ata_find_dev(device_t dev, int32_t type, int32_t revid)
 {
     device_t *children, child;
     int nchildren, i;
@@ -226,7 +226,8 @@ ata_find_dev(device_t dev, int32_t type)
 	/* check that it's on the same silicon and the device we want */
 	if (pci_get_slot(dev) == pci_get_slot(child) &&
 	    pci_get_vendor(child) == (type & 0xffff) &&
-	    pci_get_device(child) == ((type & 0xffff0000) >> 16)) {
+	    pci_get_device(child) == ((type & 0xffff0000) >> 16) &&
+	    pci_get_revid(child) >= revid) {
 	    free(children, M_TEMP);
 	    return 1;
 	}
@@ -263,11 +264,13 @@ ata_pci_match(device_t dev)
 	return "AcerLabs Aladdin ATA33 controller";
 
     case 0x05711106: 
-	if (ata_find_dev(dev, 0x05861106))
+	if (ata_find_dev(dev, 0x05861106, 0))
 	    return "VIA 82C586 ATA33 controller";
-	if (ata_find_dev(dev, 0x05961106))
+	if (ata_find_dev(dev, 0x05961106, 0x12))
+	    return "VIA 82C596B ATA66 controller";
+	if (ata_find_dev(dev, 0x05961106, 0))
 	    return "VIA 82C596 ATA33 controller";
-	if (ata_find_dev(dev, 0x06861106))
+	if (ata_find_dev(dev, 0x06861106, 0))
 	    return "VIA 82C686 ATA66 controller";
 	return "VIA Apollo ATA controller";
 
@@ -428,8 +431,9 @@ ata_pci_attach(device_t dev)
 	pci_write_config(dev, 0x60, DEV_BSIZE, 2);
 	pci_write_config(dev, 0x68, DEV_BSIZE, 2);
 	
-	/* prepare for ATA-66 on the 82C686 */
-	if (ata_find_dev(dev, 0x06861106)) {
+	/* prepare for ATA-66 on the 82C686 and rev 0x12 and newer 82C596's */
+	if (ata_find_dev(dev, 0x06861106, 0) || 
+	    ata_find_dev(dev, 0x05961106, 0x12)) {
 	    pci_write_config(dev, 0x50, 
 			     pci_read_config(dev, 0x50, 4) | 0x070f070f, 4);   
 	}
@@ -697,11 +701,11 @@ ata_pcisub_probe(device_t dev)
     scp->unit = (uintptr_t) device_get_ivars(dev);
 
     /* set the chiptype to the hostchip ID, makes life easier */
-    if (ata_find_dev(device_get_parent(dev), 0x05861106))
+    if (ata_find_dev(device_get_parent(dev), 0x05861106, 0))
 	scp->chiptype = 0x05861106;
-    else if (ata_find_dev(device_get_parent(dev), 0x05961106))
+    else if (ata_find_dev(device_get_parent(dev), 0x05961106, 0))
 	scp->chiptype = 0x05961106;
-    else if (ata_find_dev(device_get_parent(dev), 0x06861106))
+    else if (ata_find_dev(device_get_parent(dev), 0x06861106, 0))
 	scp->chiptype = 0x06861106;
     else
 	scp->chiptype = pci_get_devid(device_get_parent(dev));
diff --git a/sys/dev/ata/ata-all.h b/sys/dev/ata/ata-all.h
index 62a10b558b3d..14a3d971882e 100644
--- a/sys/dev/ata/ata-all.h
+++ b/sys/dev/ata/ata-all.h
@@ -326,6 +326,9 @@ int8_t ata_pio2mode(int32_t);
 int ata_pmode(struct ata_params *);
 int ata_wmode(struct ata_params *);
 int ata_umode(struct ata_params *);
+#if NPCI > 0
+int32_t ata_find_dev(device_t, int32_t, int32_t);
+#endif
 
 void ata_dmainit(struct ata_softc *, int32_t, int32_t, int32_t, int32_t);
 int32_t ata_dmasetup(struct ata_softc *, int32_t, int8_t *, int32_t, int32_t);
diff --git a/sys/dev/ata/ata-dma.c b/sys/dev/ata/ata-dma.c
index 0f430a53f7ab..dc96bde13a11 100644
--- a/sys/dev/ata/ata-dma.c
+++ b/sys/dev/ata/ata-dma.c
@@ -280,7 +280,24 @@ ata_dmainit(struct ata_softc *scp, int32_t device,
 	/* we could set PIO mode timings, but we assume the BIOS did that */
 	break;
 
+    case 0x74091022:	/* AMD 756 */
+	if (udmamode >= 4) {
+	    error = ata_command(scp, device, ATA_C_SETFEATURES, 0, 0, 0,
+				ATA_UDMA4, ATA_C_F_SETXFER, ATA_WAIT_READY);
+	    if (bootverbose)
+		ata_printf(scp, device,
+			   "%s setting up UDMA4 mode on AMD chip\n",
+			   (error) ? "failed" : "success");
+	    if (!error) {
+	        pci_write_config(parent, 0x53 - devno, 0xc3, 1);
+		scp->mode[ATA_DEV(device)] = ATA_UDMA4;
+		return;
+	    }
+	}
+	goto via_82c586;
+
     case 0x06861106:	/* VIA 82C686 */
+via_82c686:
 	if (udmamode >= 4) {
 	    error = ata_command(scp, device, ATA_C_SETFEATURES, 0, 0, 0,
 				ATA_UDMA4, ATA_C_F_SETXFER, ATA_WAIT_READY);
@@ -309,25 +326,14 @@ ata_dmainit(struct ata_softc *scp, int32_t device,
 	}
 	goto via_generic;
 
-    case 0x74091022:	/* AMD 756 */
-	if (udmamode >= 4) {
-	    error = ata_command(scp, device, ATA_C_SETFEATURES, 0, 0, 0,
-				ATA_UDMA4, ATA_C_F_SETXFER, ATA_WAIT_READY);
-	    if (bootverbose)
-		ata_printf(scp, device,
-			   "%s setting up UDMA4 mode on AMD chip\n",
-			   (error) ? "failed" : "success");
-	    if (!error) {
-	        pci_write_config(parent, 0x53 - devno, 0xc3, 1);
-		scp->mode[ATA_DEV(device)] = ATA_UDMA4;
-		return;
-	    }
-	}
+    case 0x05961106:	/* VIA 82C596 */
+	/* 82c596 revision >= 0x12 is like the 82c686 */
+	if (ata_find_dev(parent, 0x05961106, 0x12))
+	    goto via_82c686;
 	/* FALLTHROUGH */
 
-    case 0x05961106:	/* VIA 82C596 */
     case 0x05861106:	/* VIA 82C586 */
-
+via_82c586:
 	/* UDMA2 mode only on 82C586 > rev1, 82C596, AMD 756 */
 	if ((udmamode >= 2 && scp->chiptype == 0x05861106 &&
 	     pci_read_config(scp->dev, 0x08, 1) >= 0x01) ||