diff --git a/sys/dev/ata/ata-all.h b/sys/dev/ata/ata-all.h
index bce3497dce8f..5bc3b16cbe52 100644
--- a/sys/dev/ata/ata-all.h
+++ b/sys/dev/ata/ata-all.h
@@ -448,10 +448,11 @@ struct ata_dma {
     u_int8_t                    *work;          /* workspace */
     bus_addr_t                  work_bus;       /* bus address of dmatab */
 
-    u_int32_t                   alignment;      /* DMA engine alignment */
-    u_int32_t                   boundary;       /* DMA engine boundary */
-    u_int32_t                   max_iosize;     /* DMA engine max IO size */
-    u_int32_t                   cur_iosize;     /* DMA engine current IO size */
+    u_int32_t                   alignment;      /* DMA SG list alignment */
+    u_int32_t                   boundary;       /* DMA SG list boundary */
+    u_int32_t                   segsize;        /* DMA SG list segment size */
+    u_int32_t                   max_iosize;     /* DMA data max IO size */
+    u_int32_t                   cur_iosize;     /* DMA data current IO size */
     int                         flags;
 #define ATA_DMA_READ                    0x01    /* transaction is a read */
 #define ATA_DMA_LOADED                  0x02    /* DMA tables etc loaded */
diff --git a/sys/dev/ata/ata-chipset.c b/sys/dev/ata/ata-chipset.c
index 0bba2a6f70e3..62817f30a685 100644
--- a/sys/dev/ata/ata-chipset.c
+++ b/sys/dev/ata/ata-chipset.c
@@ -66,7 +66,6 @@ static int ata_ahci_begin_transaction(struct ata_request *request);
 static int ata_ahci_end_transaction(struct ata_request *request);
 static void ata_ahci_intr(void *data);
 static void ata_ahci_reset(device_t dev);
-static void ata_ahci_dmasetprd(void *xsc, bus_dma_segment_t *segs, int nsegs, int error);
 static void ata_ahci_dmainit(device_t dev);
 static int ata_acard_chipinit(device_t dev);
 static void ata_acard_intr(void *data);
@@ -3426,7 +3425,7 @@ ata_sii_allocate(device_t dev)
     if ((ctlr->chip->cfg2 & SIIBUG) && ch->dma) {
 	/* work around errata in early chips */
 	ch->dma->boundary = 16 * DEV_BSIZE;
-	ch->dma->max_iosize = 15 * DEV_BSIZE;
+	ch->dma->segsize = 15 * DEV_BSIZE;
     }
 
     ata_generic_hw(dev);
@@ -3553,6 +3552,13 @@ ata_sii_reset(device_t dev)
     /* disable PHY state change interrupt */
     ATA_OUTL(ctlr->r_res2, 0x148 + offset, ~(1 << 16));
 
+    /* reset controller part for this channel */
+    ATA_OUTL(ctlr->r_res2, 0x48,
+	     ATA_INL(ctlr->r_res2, 0x48) | (0xc0 >> ch->unit));
+    DELAY(1000);
+    ATA_OUTL(ctlr->r_res2, 0x48,
+	     ATA_INL(ctlr->r_res2, 0x48) & ~(0xc0 >> ch->unit));
+
     ata_sata_phy_enable(ch);
 
     /* enable PHY state change interrupt */
diff --git a/sys/dev/ata/ata-dma.c b/sys/dev/ata/ata-dma.c
index f8c4411d73c4..4032a48f6fc2 100644
--- a/sys/dev/ata/ata-dma.c
+++ b/sys/dev/ata/ata-dma.c
@@ -77,8 +77,9 @@ ata_dmainit(device_t dev)
 	ch->dma->load = ata_dmaload;
 	ch->dma->unload = ata_dmaunload;
 	ch->dma->alignment = 2;
-	ch->dma->max_iosize = 128 * DEV_BSIZE;
 	ch->dma->boundary = 128 * DEV_BSIZE;
+	ch->dma->segsize = 128 * DEV_BSIZE;
+	ch->dma->max_iosize = 128 * DEV_BSIZE;
     }
 }
 
@@ -99,8 +100,8 @@ ata_dmaalloc(device_t dev)
 
     if (bus_dma_tag_create(NULL, ch->dma->alignment, 0,
 			   BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR,
-			   NULL, NULL, 256 * DEV_BSIZE,
-			   ATA_DMA_ENTRIES, ch->dma->max_iosize,
+			   NULL, NULL, ch->dma->max_iosize,
+			   ATA_DMA_ENTRIES, ch->dma->segsize,
 			   0, NULL, NULL, &ch->dma->dmatag))
 	goto error;
 
@@ -112,8 +113,8 @@ ata_dmaalloc(device_t dev)
 
     if (bus_dma_tag_create(ch->dma->dmatag,ch->dma->alignment,ch->dma->boundary,
 			   BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR,
-			   NULL, NULL, 256 * DEV_BSIZE,
-			   ATA_DMA_ENTRIES, ch->dma->max_iosize,
+			   NULL, NULL, ch->dma->max_iosize,
+			   ATA_DMA_ENTRIES, ch->dma->segsize,
 			   BUS_DMA_ALLOCNOW, NULL, NULL, &ch->dma->data_tag))
 	goto error;