diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index fc94f20..97bfb6b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -293,6 +293,8 @@ struct dma_features {
 #define STMMAC_CHAIN_MODE	0x1
 #define STMMAC_RING_MODE	0x2
 
+#define JUMBO_LEN		9000
+
 struct stmmac_desc_ops {
 	/* DMA RX descriptor ring initialization */
 	void (*init_rx_desc) (struct dma_desc *p, int disable_rx_ic, int mode,
@@ -369,7 +371,7 @@ struct stmmac_dma_ops {
 
 struct stmmac_ops {
 	/* MAC core initialization */
-	void (*core_init) (void __iomem *ioaddr);
+	void (*core_init) (void __iomem *ioaddr, int mtu);
 	/* Enable and verify that the IPC module is supported */
 	int (*rx_ipc) (void __iomem *ioaddr);
 	/* Dump MAC registers */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
index c12aabb..f37d90f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
@@ -126,11 +126,8 @@ enum power_event {
 #define GMAC_ANE_PSE		(3 << 7)
 #define GMAC_ANE_PSE_SHIFT	7
 
- /* GMAC Configuration defines */
-#define GMAC_CONTROL_TC	0x01000000	/* Transmit Conf. in RGMII/SGMII */
-#define GMAC_CONTROL_WD	0x00800000	/* Disable Watchdog on receive */
-
 /* GMAC Configuration defines */
+#define GMAC_CONTROL_2K 0x08000000	/* IEEE 802.3as 2K packets */
 #define GMAC_CONTROL_TC	0x01000000	/* Transmit Conf. in RGMII/SGMII */
 #define GMAC_CONTROL_WD	0x00800000	/* Disable Watchdog on receive */
 #define GMAC_CONTROL_JD	0x00400000	/* Jabber disable */
@@ -156,7 +153,7 @@ enum inter_frame_gap {
 #define GMAC_CONTROL_RE		0x00000004	/* Receiver Enable */
 
 #define GMAC_CORE_INIT (GMAC_CONTROL_JD | GMAC_CONTROL_PS | GMAC_CONTROL_ACS | \
-			GMAC_CONTROL_JE | GMAC_CONTROL_BE)
+			GMAC_CONTROL_BE)
 
 /* GMAC Frame Filter defines */
 #define GMAC_FRAME_FILTER_PR	0x00000001	/* Promiscuous Mode */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
index cdd9268..b3e148e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
@@ -32,10 +32,15 @@
 #include <asm/io.h>
 #include "dwmac1000.h"
 
-static void dwmac1000_core_init(void __iomem *ioaddr)
+static void dwmac1000_core_init(void __iomem *ioaddr, int mtu)
 {
 	u32 value = readl(ioaddr + GMAC_CONTROL);
 	value |= GMAC_CORE_INIT;
+	if (mtu > 1500)
+		value |= GMAC_CONTROL_2K;
+	if (mtu > 2000)
+		value |= GMAC_CONTROL_JE;
+
 	writel(value, ioaddr + GMAC_CONTROL);
 
 	/* Mask GMAC interrupts */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac100_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac100_core.c
index 5857d67..2ff767b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac100_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac100_core.c
@@ -32,7 +32,7 @@
 #include <asm/io.h>
 #include "dwmac100.h"
 
-static void dwmac100_core_init(void __iomem *ioaddr)
+static void dwmac100_core_init(void __iomem *ioaddr, int mtu)
 {
 	u32 value = readl(ioaddr + MAC_CONTROL);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index ecdc8ab..58f7744 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -52,7 +52,6 @@
 #include "stmmac.h"
 
 #define STMMAC_ALIGN(x)	L1_CACHE_ALIGN(x)
-#define JUMBO_LEN	9000
 
 /* Module parameters */
 #define TX_TIMEO	5000
@@ -91,7 +90,7 @@ static int tc = TC_DEFAULT;
 module_param(tc, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(tc, "DMA threshold control value");
 
-#define DMA_BUFFER_SIZE	BUF_SIZE_2KiB
+#define DMA_BUFFER_SIZE	BUF_SIZE_4KiB
 static int buf_sz = DMA_BUFFER_SIZE;
 module_param(buf_sz, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(buf_sz, "DMA buffer size");
@@ -990,6 +989,8 @@ static int init_dma_desc_rings(struct net_device *dev)
 	if (bfsize < BUF_SIZE_16KiB)
 		bfsize = stmmac_set_bfsize(dev->mtu, priv->dma_buf_sz);
 
+	priv->dma_buf_sz = bfsize;
+
 	if (netif_msg_probe(priv))
 		pr_debug("%s: txsize %d, rxsize %d, bfsize %d\n", __func__,
 			 txsize, rxsize, bfsize);
@@ -1079,7 +1080,6 @@ static int init_dma_desc_rings(struct net_device *dev)
 	}
 	priv->cur_rx = 0;
 	priv->dirty_rx = (unsigned int)(i - rxsize);
-	priv->dma_buf_sz = bfsize;
 	buf_sz = bfsize;
 
 	/* Setup the chained descriptor addresses */
@@ -1642,7 +1642,7 @@ static int stmmac_open(struct net_device *dev)
 		priv->plat->bus_setup(priv->ioaddr);
 
 	/* Initialize the MAC Core */
-	priv->hw->mac->core_init(priv->ioaddr);
+	priv->hw->mac->core_init(priv->ioaddr, dev->mtu);
 
 	/* Request the IRQ lines */
 	ret = request_irq(dev->irq, stmmac_interrupt,
@@ -2248,6 +2248,9 @@ static int stmmac_change_mtu(struct net_device *dev, int new_mtu)
 	else
 		max_mtu = SKB_MAX_HEAD(NET_SKB_PAD + NET_IP_ALIGN);
 
+	if (priv->plat->maxmtu < max_mtu)
+		max_mtu = priv->plat->maxmtu;
+
 	if ((new_mtu < 46) || (new_mtu > max_mtu)) {
 		pr_err("%s: invalid MTU, max MTU is: %d\n", dev->name, max_mtu);
 		return -EINVAL;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 38bd1f4..48ec035 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -52,6 +52,11 @@ static int stmmac_probe_config_dt(struct platform_device *pdev,
 					   sizeof(struct stmmac_mdio_bus_data),
 					   GFP_KERNEL);
 
+	/* Set the maxmtu to a default of JUMBO_LEN in case the
+	 * parameter is not present in the device tree.
+	 */
+	plat->maxmtu = JUMBO_LEN;
+
 	/*
 	 * Currently only the properties needed on SPEAr600
 	 * are provided. All other properties should be added
@@ -60,6 +65,14 @@ static int stmmac_probe_config_dt(struct platform_device *pdev,
 	if (of_device_is_compatible(np, "st,spear600-gmac") ||
 		of_device_is_compatible(np, "snps,dwmac-3.70a") ||
 		of_device_is_compatible(np, "snps,dwmac")) {
+		/* Note that the max-frame-size parameter as defined in the
+		 * ePAPR v1.1 spec is defined as max-frame-size, it's
+		 * actually used as the IEEE definition of MAC Client
+		 * data, or MTU. The ePAPR specification is confusing as
+		 * the definition is max-frame-size, but usage examples
+		 * are clearly MTUs
+		 */
+		of_property_read_u32(np, "max-frame-size", &plat->maxmtu);
 		plat->has_gmac = 1;
 		plat->pmt = 1;
 	}
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index bb5deb0..9689706 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -110,6 +110,7 @@ struct plat_stmmacenet_data {
 	int force_sf_dma_mode;
 	int force_thresh_dma_mode;
 	int riwt_off;
+	int maxmtu;
 	void (*fix_mac_speed)(void *priv, unsigned int speed);
 	void (*bus_setup)(void __iomem *ioaddr);
 	int (*init)(struct platform_device *pdev);
