Index: sys/dev/mmc/host/dwmmc.c
===================================================================
--- sys/dev/mmc/host/dwmmc.c
+++ sys/dev/mmc/host/dwmmc.c
@@ -99,16 +99,15 @@
 #define	DWMMC_ERR_FLAGS		(DWMMC_DATA_ERR_FLAGS | DWMMC_CMD_ERR_FLAGS \
 				|SDMMC_INTMASK_HLE)
 
-#define	DES0_DIC	(1 << 1)
-#define	DES0_LD		(1 << 2)
-#define	DES0_FS		(1 << 3)
-#define	DES0_CH		(1 << 4)
-#define	DES0_ER		(1 << 5)
-#define	DES0_CES	(1 << 30)
-#define	DES0_OWN	(1 << 31)
+#define	DES0_DIC	(1 << 1)	/* Disable Interrupt on Completion */
+#define	DES0_LD		(1 << 2)	/* Last Descriptor */
+#define	DES0_FS		(1 << 3)	/* First Descriptor */
+#define	DES0_CH		(1 << 4)	/* second address CHained */
+#define	DES0_ER		(1 << 5)	/* End of Ring */
+#define	DES0_CES	(1 << 30)	/* Card Error Summary */
+#define	DES0_OWN	(1 << 31)	/* OWN */
 
-#define	DES1_BS1_MASK	0xfff
-#define	DES1_BS1_SHIFT	0
+#define	DES1_BS1_MASK	0x1fff
 
 struct idmac_desc {
 	uint32_t	des0;	/* control */
@@ -117,9 +116,10 @@
 	uint32_t	des3;	/* buf2 phys addr or next descr */
 };
 
-#define	DESC_MAX	256
-#define	DESC_SIZE	(sizeof(struct idmac_desc) * DESC_MAX)
+#define	IDMAC_DESC_SEGS	(PAGE_SIZE / (sizeof(struct idmac_desc)))
+#define	IDMAC_DESC_SIZE	(sizeof(struct idmac_desc) * IDMAC_DESC_SEGS)
 #define	DEF_MSIZE	0x2	/* Burst size of multiple transaction */
+#define	IDMAC_MAX_SIZE	4096
 
 static void dwmmc_next_operation(struct dwmmc_softc *);
 static int dwmmc_setup_bus(struct dwmmc_softc *, int);
@@ -162,7 +162,7 @@
 
 	for (idx = 0; idx < nsegs; idx++) {
 		sc->desc_ring[idx].des0 = (DES0_OWN | DES0_DIC | DES0_CH);
-		sc->desc_ring[idx].des1 = segs[idx].ds_len;
+		sc->desc_ring[idx].des1 = segs[idx].ds_len & DES1_BS1_MASK;
 		sc->desc_ring[idx].des2 = segs[idx].ds_addr;
 
 		if (idx == 0)
@@ -213,8 +213,8 @@
 	    BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
 	    BUS_SPACE_MAXADDR,		/* highaddr */
 	    NULL, NULL,			/* filter, filterarg */
-	    DESC_SIZE, 1, 		/* maxsize, nsegments */
-	    DESC_SIZE,			/* maxsegsize */
+	    IDMAC_DESC_SIZE, 1,		/* maxsize, nsegments */
+	    IDMAC_DESC_SIZE,		/* maxsegsize */
 	    0,				/* flags */
 	    NULL, NULL,			/* lockfunc, lockarg */
 	    &sc->desc_tag);
@@ -234,7 +234,7 @@
 	}
 
 	error = bus_dmamap_load(sc->desc_tag, sc->desc_map,
-	    sc->desc_ring, DESC_SIZE, dwmmc_get1paddr,
+	    sc->desc_ring, IDMAC_DESC_SIZE, dwmmc_get1paddr,
 	    &sc->desc_ring_paddr, 0);
 	if (error != 0) {
 		device_printf(sc->dev,
@@ -242,23 +242,25 @@
 		return (1);
 	}
 
-	for (idx = 0; idx < sc->desc_count; idx++) {
+	for (idx = 0; idx < IDMAC_DESC_SEGS; idx++) {
 		sc->desc_ring[idx].des0 = DES0_CH;
 		sc->desc_ring[idx].des1 = 0;
-		nidx = (idx + 1) % sc->desc_count;
+		nidx = (idx + 1) % IDMAC_DESC_SEGS;
 		sc->desc_ring[idx].des3 = sc->desc_ring_paddr + \
 		    (nidx * sizeof(struct idmac_desc));
 	}
+	sc->desc_ring[idx - 1].des3 = sc->desc_ring_paddr;
+	sc->desc_ring[idx - 1].des0 |= DES0_ER;
 
 	error = bus_dma_tag_create(
 	    bus_get_dma_tag(sc->dev),	/* Parent tag. */
-	    4096, 0,			/* alignment, boundary */
+	    PAGE_SIZE, 0,		/* alignment, boundary */
 	    BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
 	    BUS_SPACE_MAXADDR,		/* highaddr */
 	    NULL, NULL,			/* filter, filterarg */
-	    sc->desc_count * MMC_SECTOR_SIZE, /* maxsize */
-	    sc->desc_count,		/* nsegments */
-	    MMC_SECTOR_SIZE,		/* maxsegsize */
+	    IDMAC_MAX_SIZE * IDMAC_DESC_SEGS,	/* maxsize */
+	    IDMAC_DESC_SEGS,		/* nsegments */
+	    IDMAC_MAX_SIZE,		/* maxsegsize */
 	    0,				/* flags */
 	    NULL, NULL,			/* lockfunc, lockarg */
 	    &sc->buf_tag);
@@ -664,9 +666,6 @@
 	device_printf(dev, "Hardware version ID is %04x\n",
 		READ4(sc, SDMMC_VERID) & 0xffff);
 
-	if (sc->desc_count == 0)
-		sc->desc_count = DESC_MAX;
-
 	/* XXX: we support operation for slot index 0 only */
 	slot = 0;
 	if (sc->pwren_inverted) {
@@ -1278,7 +1277,7 @@
 		*(int *)result = sc->host.caps;
 		break;
 	case MMCBR_IVAR_MAX_DATA:
-		*(int *)result = sc->desc_count;
+		*(int *)result = (IDMAC_MAX_SIZE * IDMAC_DESC_SEGS) / MMC_SECTOR_SIZE;
 		break;
 	case MMCBR_IVAR_TIMING:
 		*(int *)result = sc->host.ios.timing;
Index: sys/dev/mmc/host/dwmmc_hisi.c
===================================================================
--- sys/dev/mmc/host/dwmmc_hisi.c
+++ sys/dev/mmc/host/dwmmc_hisi.c
@@ -79,7 +79,6 @@
 	 * DMA when the controller is not cache-coherent on arm64.
 	 */
 	sc->use_pio = 1;
-	sc->desc_count = 1;
 
 	return (dwmmc_attach(dev));
 }
Index: sys/dev/mmc/host/dwmmc_var.h
===================================================================
--- sys/dev/mmc/host/dwmmc_var.h
+++ sys/dev/mmc/host/dwmmc_var.h
@@ -60,7 +60,6 @@
 	uint32_t		use_auto_stop;
 	uint32_t		use_pio;
 	uint32_t		pwren_inverted;
-	u_int			desc_count;
 	device_t		child;
 	struct task		card_task;	/* Card presence check task */
 	struct timeout_task	card_delayed_task;/* Card insert delayed task */