Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:

 1) Seccomp BPF filters can now be JIT'd, from Alexei Starovoitov.

 2) Multiqueue support in xen-netback and xen-netfront, from Andrew J
    Benniston.

 3) Allow tweaking of aggregation settings in cdc_ncm driver, from Bjørn
    Mork.

 4) BPF now has a "random" opcode, from Chema Gonzalez.

 5) Add more BPF documentation and improve test framework, from Daniel
    Borkmann.

 6) Support TCP fastopen over ipv6, from Daniel Lee.

 7) Add software TSO helper functions and use them to support software
    TSO in mvneta and mv643xx_eth drivers.  From Ezequiel Garcia.

 8) Support software TSO in fec driver too, from Nimrod Andy.

 9) Add Broadcom SYSTEMPORT driver, from Florian Fainelli.

10) Handle broadcasts more gracefully over macvlan when there are large
    numbers of interfaces configured, from Herbert Xu.

11) Allow more control over fwmark used for non-socket based responses,
    from Lorenzo Colitti.

12) Do TCP congestion window limiting based upon measurements, from Neal
    Cardwell.

13) Support busy polling in SCTP, from Neal Horman.

14) Allow RSS key to be configured via ethtool, from Venkata Duvvuru.

15) Bridge promisc mode handling improvements from Vlad Yasevich.

16) Don't use inetpeer entries to implement ID generation any more, it
    performs poorly, from Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1522 commits)
  rtnetlink: fix userspace API breakage for iproute2 < v3.9.0
  tcp: fixing TLP's FIN recovery
  net: fec: Add software TSO support
  net: fec: Add Scatter/gather support
  net: fec: Increase buffer descriptor entry number
  net: fec: Factorize feature setting
  net: fec: Enable IP header hardware checksum
  net: fec: Factorize the .xmit transmit function
  bridge: fix compile error when compiling without IPv6 support
  bridge: fix smatch warning / potential null pointer dereference
  via-rhine: fix full-duplex with autoneg disable
  bnx2x: Enlarge the dorq threshold for VFs
  bnx2x: Check for UNDI in uncommon branch
  bnx2x: Fix 1G-baseT link
  bnx2x: Fix link for KR with swapped polarity lane
  sctp: Fix sk_ack_backlog wrap-around problem
  net/core: Add VF link state control policy
  net/fsl: xgmac_mdio is dependent on OF_MDIO
  net/fsl: Make xgmac_mdio read error message useful
  net_sched: drr: warn when qdisc is not work conserving
  ...

1 files changed, 560 insertions, 180 deletions

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 9a2bd11943eb..80a844e0ae03 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -65,19 +65,384 @@ static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx);
 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
 static struct usb_driver cdc_ncm_driver;
 
-static int cdc_ncm_setup(struct usbnet *dev)
+struct cdc_ncm_stats {
+	char stat_string[ETH_GSTRING_LEN];
+	int sizeof_stat;
+	int stat_offset;
+};
+
+#define CDC_NCM_STAT(str, m) { \
+		.stat_string = str, \
+		.sizeof_stat = sizeof(((struct cdc_ncm_ctx *)0)->m), \
+		.stat_offset = offsetof(struct cdc_ncm_ctx, m) }
+#define CDC_NCM_SIMPLE_STAT(m)	CDC_NCM_STAT(__stringify(m), m)
+
+static const struct cdc_ncm_stats cdc_ncm_gstrings_stats[] = {
+	CDC_NCM_SIMPLE_STAT(tx_reason_ntb_full),
+	CDC_NCM_SIMPLE_STAT(tx_reason_ndp_full),
+	CDC_NCM_SIMPLE_STAT(tx_reason_timeout),
+	CDC_NCM_SIMPLE_STAT(tx_reason_max_datagram),
+	CDC_NCM_SIMPLE_STAT(tx_overhead),
+	CDC_NCM_SIMPLE_STAT(tx_ntbs),
+	CDC_NCM_SIMPLE_STAT(rx_overhead),
+	CDC_NCM_SIMPLE_STAT(rx_ntbs),
+};
+
+static int cdc_ncm_get_sset_count(struct net_device __always_unused *netdev, int sset)
+{
+	switch (sset) {
+	case ETH_SS_STATS:
+		return ARRAY_SIZE(cdc_ncm_gstrings_stats);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static void cdc_ncm_get_ethtool_stats(struct net_device *netdev,
+				    struct ethtool_stats __always_unused *stats,
+				    u64 *data)
+{
+	struct usbnet *dev = netdev_priv(netdev);
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	int i;
+	char *p = NULL;
+
+	for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
+		p = (char *)ctx + cdc_ncm_gstrings_stats[i].stat_offset;
+		data[i] = (cdc_ncm_gstrings_stats[i].sizeof_stat == sizeof(u64)) ? *(u64 *)p : *(u32 *)p;
+	}
+}
+
+static void cdc_ncm_get_strings(struct net_device __always_unused *netdev, u32 stringset, u8 *data)
+{
+	u8 *p = data;
+	int i;
+
+	switch (stringset) {
+	case ETH_SS_STATS:
+		for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
+			memcpy(p, cdc_ncm_gstrings_stats[i].stat_string, ETH_GSTRING_LEN);
+			p += ETH_GSTRING_LEN;
+		}
+	}
+}
+
+static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx);
+
+static const struct ethtool_ops cdc_ncm_ethtool_ops = {
+	.get_settings      = usbnet_get_settings,
+	.set_settings      = usbnet_set_settings,
+	.get_link          = usbnet_get_link,
+	.nway_reset        = usbnet_nway_reset,
+	.get_drvinfo       = usbnet_get_drvinfo,
+	.get_msglevel      = usbnet_get_msglevel,
+	.set_msglevel      = usbnet_set_msglevel,
+	.get_ts_info       = ethtool_op_get_ts_info,
+	.get_sset_count    = cdc_ncm_get_sset_count,
+	.get_strings       = cdc_ncm_get_strings,
+	.get_ethtool_stats = cdc_ncm_get_ethtool_stats,
+};
+
+static u32 cdc_ncm_check_rx_max(struct usbnet *dev, u32 new_rx)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	u32 val, max, min;
+
+	/* clamp new_rx to sane values */
+	min = USB_CDC_NCM_NTB_MIN_IN_SIZE;
+	max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_RX, le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
+
+	/* dwNtbInMaxSize spec violation? Use MIN size for both limits */
+	if (max < min) {
+		dev_warn(&dev->intf->dev, "dwNtbInMaxSize=%u is too small. Using %u\n",
+			 le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize), min);
+		max = min;
+	}
+
+	val = clamp_t(u32, new_rx, min, max);
+	if (val != new_rx)
+		dev_dbg(&dev->intf->dev, "rx_max must be in the [%u, %u] range\n", min, max);
+
+	return val;
+}
+
+static u32 cdc_ncm_check_tx_max(struct usbnet *dev, u32 new_tx)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	u32 val, max, min;
+
+	/* clamp new_tx to sane values */
+	min = ctx->max_datagram_size + ctx->max_ndp_size + sizeof(struct usb_cdc_ncm_nth16);
+	max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_TX, le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
+
+	/* some devices set dwNtbOutMaxSize too low for the above default */
+	min = min(min, max);
+
+	val = clamp_t(u32, new_tx, min, max);
+	if (val != new_tx)
+		dev_dbg(&dev->intf->dev, "tx_max must be in the [%u, %u] range\n", min, max);
+
+	return val;
+}
+
+static ssize_t cdc_ncm_show_min_tx_pkt(struct device *d, struct device_attribute *attr, char *buf)
+{
+	struct usbnet *dev = netdev_priv(to_net_dev(d));
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+	return sprintf(buf, "%u\n", ctx->min_tx_pkt);
+}
+
+static ssize_t cdc_ncm_show_rx_max(struct device *d, struct device_attribute *attr, char *buf)
+{
+	struct usbnet *dev = netdev_priv(to_net_dev(d));
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+	return sprintf(buf, "%u\n", ctx->rx_max);
+}
+
+static ssize_t cdc_ncm_show_tx_max(struct device *d, struct device_attribute *attr, char *buf)
+{
+	struct usbnet *dev = netdev_priv(to_net_dev(d));
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+	return sprintf(buf, "%u\n", ctx->tx_max);
+}
+
+static ssize_t cdc_ncm_show_tx_timer_usecs(struct device *d, struct device_attribute *attr, char *buf)
+{
+	struct usbnet *dev = netdev_priv(to_net_dev(d));
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+	return sprintf(buf, "%u\n", ctx->timer_interval / (u32)NSEC_PER_USEC);
+}
+
+static ssize_t cdc_ncm_store_min_tx_pkt(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct usbnet *dev = netdev_priv(to_net_dev(d));
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	unsigned long val;
+
+	/* no need to restrict values - anything from 0 to infinity is OK */
+	if (kstrtoul(buf, 0, &val))
+		return -EINVAL;
+
+	ctx->min_tx_pkt = val;
+	return len;
+}
+
+static ssize_t cdc_ncm_store_rx_max(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct usbnet *dev = netdev_priv(to_net_dev(d));
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	unsigned long val;
+
+	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_rx_max(dev, val) != val)
+		return -EINVAL;
+
+	cdc_ncm_update_rxtx_max(dev, val, ctx->tx_max);
+	return len;
+}
+
+static ssize_t cdc_ncm_store_tx_max(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
 {
+	struct usbnet *dev = netdev_priv(to_net_dev(d));
 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	unsigned long val;
+
+	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_tx_max(dev, val) != val)
+		return -EINVAL;
+
+	cdc_ncm_update_rxtx_max(dev, ctx->rx_max, val);
+	return len;
+}
+
+static ssize_t cdc_ncm_store_tx_timer_usecs(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct usbnet *dev = netdev_priv(to_net_dev(d));
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	ssize_t ret;
+	unsigned long val;
+
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
+		return ret;
+	if (val && (val < CDC_NCM_TIMER_INTERVAL_MIN || val > CDC_NCM_TIMER_INTERVAL_MAX))
+		return -EINVAL;
+
+	spin_lock_bh(&ctx->mtx);
+	ctx->timer_interval = val * NSEC_PER_USEC;
+	if (!ctx->timer_interval)
+		ctx->tx_timer_pending = 0;
+	spin_unlock_bh(&ctx->mtx);
+	return len;
+}
+
+static DEVICE_ATTR(min_tx_pkt, S_IRUGO | S_IWUSR, cdc_ncm_show_min_tx_pkt, cdc_ncm_store_min_tx_pkt);
+static DEVICE_ATTR(rx_max, S_IRUGO | S_IWUSR, cdc_ncm_show_rx_max, cdc_ncm_store_rx_max);
+static DEVICE_ATTR(tx_max, S_IRUGO | S_IWUSR, cdc_ncm_show_tx_max, cdc_ncm_store_tx_max);
+static DEVICE_ATTR(tx_timer_usecs, S_IRUGO | S_IWUSR, cdc_ncm_show_tx_timer_usecs, cdc_ncm_store_tx_timer_usecs);
+
+#define NCM_PARM_ATTR(name, format, tocpu)				\
+static ssize_t cdc_ncm_show_##name(struct device *d, struct device_attribute *attr, char *buf) \
+{ \
+	struct usbnet *dev = netdev_priv(to_net_dev(d)); \
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; \
+	return sprintf(buf, format "\n", tocpu(ctx->ncm_parm.name));	\
+} \
+static DEVICE_ATTR(name, S_IRUGO, cdc_ncm_show_##name, NULL)
+
+NCM_PARM_ATTR(bmNtbFormatsSupported, "0x%04x", le16_to_cpu);
+NCM_PARM_ATTR(dwNtbInMaxSize, "%u", le32_to_cpu);
+NCM_PARM_ATTR(wNdpInDivisor, "%u", le16_to_cpu);
+NCM_PARM_ATTR(wNdpInPayloadRemainder, "%u", le16_to_cpu);
+NCM_PARM_ATTR(wNdpInAlignment, "%u", le16_to_cpu);
+NCM_PARM_ATTR(dwNtbOutMaxSize, "%u", le32_to_cpu);
+NCM_PARM_ATTR(wNdpOutDivisor, "%u", le16_to_cpu);
+NCM_PARM_ATTR(wNdpOutPayloadRemainder, "%u", le16_to_cpu);
+NCM_PARM_ATTR(wNdpOutAlignment, "%u", le16_to_cpu);
+NCM_PARM_ATTR(wNtbOutMaxDatagrams, "%u", le16_to_cpu);
+
+static struct attribute *cdc_ncm_sysfs_attrs[] = {
+	&dev_attr_min_tx_pkt.attr,
+	&dev_attr_rx_max.attr,
+	&dev_attr_tx_max.attr,
+	&dev_attr_tx_timer_usecs.attr,
+	&dev_attr_bmNtbFormatsSupported.attr,
+	&dev_attr_dwNtbInMaxSize.attr,
+	&dev_attr_wNdpInDivisor.attr,
+	&dev_attr_wNdpInPayloadRemainder.attr,
+	&dev_attr_wNdpInAlignment.attr,
+	&dev_attr_dwNtbOutMaxSize.attr,
+	&dev_attr_wNdpOutDivisor.attr,
+	&dev_attr_wNdpOutPayloadRemainder.attr,
+	&dev_attr_wNdpOutAlignment.attr,
+	&dev_attr_wNtbOutMaxDatagrams.attr,
+	NULL,
+};
+
+static struct attribute_group cdc_ncm_sysfs_attr_group = {
+	.name = "cdc_ncm",
+	.attrs = cdc_ncm_sysfs_attrs,
+};
+
+/* handle rx_max and tx_max changes */
+static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
 	u32 val;
-	u8 flags;
-	u8 iface_no;
-	int err;
-	int eth_hlen;
-	u16 mbim_mtu;
-	u16 ntb_fmt_supported;
-	__le16 max_datagram_size;
 
-	iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
+	val = cdc_ncm_check_rx_max(dev, new_rx);
+
+	/* inform device about NTB input size changes */
+	if (val != ctx->rx_max) {
+		__le32 dwNtbInMaxSize = cpu_to_le32(val);
+
+		dev_info(&dev->intf->dev, "setting rx_max = %u\n", val);
+
+		/* tell device to use new size */
+		if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
+				     USB_TYPE_CLASS | USB_DIR_OUT
+				     | USB_RECIP_INTERFACE,
+				     0, iface_no, &dwNtbInMaxSize, 4) < 0)
+			dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
+		else
+			ctx->rx_max = val;
+	}
+
+	/* usbnet use these values for sizing rx queues */
+	if (dev->rx_urb_size != ctx->rx_max) {
+		dev->rx_urb_size = ctx->rx_max;
+		if (netif_running(dev->net))
+			usbnet_unlink_rx_urbs(dev);
+	}
+
+	val = cdc_ncm_check_tx_max(dev, new_tx);
+	if (val != ctx->tx_max)
+		dev_info(&dev->intf->dev, "setting tx_max = %u\n", val);
+
+	/* Adding a pad byte here if necessary simplifies the handling
+	 * in cdc_ncm_fill_tx_frame, making tx_max always represent
+	 * the real skb max size.
+	 *
+	 * We cannot use dev->maxpacket here because this is called from
+	 * .bind which is called before usbnet sets up dev->maxpacket
+	 */
+	if (val != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
+	    val % usb_maxpacket(dev->udev, dev->out, 1) == 0)
+		val++;
+
+	/* we might need to flush any pending tx buffers if running */
+	if (netif_running(dev->net) && val > ctx->tx_max) {
+		netif_tx_lock_bh(dev->net);
+		usbnet_start_xmit(NULL, dev->net);
+		/* make sure tx_curr_skb is reallocated if it was empty */
+		if (ctx->tx_curr_skb) {
+			dev_kfree_skb_any(ctx->tx_curr_skb);
+			ctx->tx_curr_skb = NULL;
+		}
+		ctx->tx_max = val;
+		netif_tx_unlock_bh(dev->net);
+	} else {
+		ctx->tx_max = val;
+	}
+
+	dev->hard_mtu = ctx->tx_max;
+
+	/* max qlen depend on hard_mtu and rx_urb_size */
+	usbnet_update_max_qlen(dev);
+
+	/* never pad more than 3 full USB packets per transfer */
+	ctx->min_tx_pkt = clamp_t(u16, ctx->tx_max - 3 * usb_maxpacket(dev->udev, dev->out, 1),
+				  CDC_NCM_MIN_TX_PKT, ctx->tx_max);
+}
+
+/* helpers for NCM and MBIM differences */
+static u8 cdc_ncm_flags(struct usbnet *dev)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
+		return ctx->mbim_desc->bmNetworkCapabilities;
+	if (ctx->func_desc)
+		return ctx->func_desc->bmNetworkCapabilities;
+	return 0;
+}
+
+static int cdc_ncm_eth_hlen(struct usbnet *dev)
+{
+	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
+		return 0;
+	return ETH_HLEN;
+}
+
+static u32 cdc_ncm_min_dgram_size(struct usbnet *dev)
+{
+	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
+		return CDC_MBIM_MIN_DATAGRAM_SIZE;
+	return CDC_NCM_MIN_DATAGRAM_SIZE;
+}
+
+static u32 cdc_ncm_max_dgram_size(struct usbnet *dev)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
+		return le16_to_cpu(ctx->mbim_desc->wMaxSegmentSize);
+	if (ctx->ether_desc)
+		return le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
+	return CDC_NCM_MAX_DATAGRAM_SIZE;
+}
+
+/* initial one-time device setup.  MUST be called with the data interface
+ * in altsetting 0
+ */
+static int cdc_ncm_init(struct usbnet *dev)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
+	int err;
 
 	err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_PARAMETERS,
 			      USB_TYPE_CLASS | USB_DIR_IN
@@ -89,7 +454,36 @@ static int cdc_ncm_setup(struct usbnet *dev)
 		return err; /* GET_NTB_PARAMETERS is required */
 	}
 
-	/* read correct set of parameters according to device mode */
+	/* set CRC Mode */
+	if (cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_CRC_MODE) {
+		dev_dbg(&dev->intf->dev, "Setting CRC mode off\n");
+		err = usbnet_write_cmd(dev, USB_CDC_SET_CRC_MODE,
+				       USB_TYPE_CLASS | USB_DIR_OUT
+				       | USB_RECIP_INTERFACE,
+				       USB_CDC_NCM_CRC_NOT_APPENDED,
+				       iface_no, NULL, 0);
+		if (err < 0)
+			dev_err(&dev->intf->dev, "SET_CRC_MODE failed\n");
+	}
+
+	/* set NTB format, if both formats are supported.
+	 *
+	 * "The host shall only send this command while the NCM Data
+	 *  Interface is in alternate setting 0."
+	 */
+	if (le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported) &
+						USB_CDC_NCM_NTB32_SUPPORTED) {
+		dev_dbg(&dev->intf->dev, "Setting NTB format to 16-bit\n");
+		err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
+				       USB_TYPE_CLASS | USB_DIR_OUT
+				       | USB_RECIP_INTERFACE,
+				       USB_CDC_NCM_NTB16_FORMAT,
+				       iface_no, NULL, 0);
+		if (err < 0)
+			dev_err(&dev->intf->dev, "SET_NTB_FORMAT failed\n");
+	}
+
+	/* set initial device values */
 	ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
 	ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
 	ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
@@ -97,72 +491,79 @@ static int cdc_ncm_setup(struct usbnet *dev)
 	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
 	/* devices prior to NCM Errata shall set this field to zero */
 	ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
-	ntb_fmt_supported = le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported);
-
-	/* there are some minor differences in NCM and MBIM defaults */
-	if (cdc_ncm_comm_intf_is_mbim(ctx->control->cur_altsetting)) {
-		if (!ctx->mbim_desc)
-			return -EINVAL;
-		eth_hlen = 0;
-		flags = ctx->mbim_desc->bmNetworkCapabilities;
-		ctx->max_datagram_size = le16_to_cpu(ctx->mbim_desc->wMaxSegmentSize);
-		if (ctx->max_datagram_size < CDC_MBIM_MIN_DATAGRAM_SIZE)
-			ctx->max_datagram_size = CDC_MBIM_MIN_DATAGRAM_SIZE;
-	} else {
-		if (!ctx->func_desc)
-			return -EINVAL;
-		eth_hlen = ETH_HLEN;
-		flags = ctx->func_desc->bmNetworkCapabilities;
-		ctx->max_datagram_size = le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
-		if (ctx->max_datagram_size < CDC_NCM_MIN_DATAGRAM_SIZE)
-			ctx->max_datagram_size = CDC_NCM_MIN_DATAGRAM_SIZE;
-	}
-
-	/* common absolute max for NCM and MBIM */
-	if (ctx->max_datagram_size > CDC_NCM_MAX_DATAGRAM_SIZE)
-		ctx->max_datagram_size = CDC_NCM_MAX_DATAGRAM_SIZE;
 
 	dev_dbg(&dev->intf->dev,
 		"dwNtbInMaxSize=%u dwNtbOutMaxSize=%u wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
 		ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
-		ctx->tx_ndp_modulus, ctx->tx_max_datagrams, flags);
+		ctx->tx_ndp_modulus, ctx->tx_max_datagrams, cdc_ncm_flags(dev));
 
 	/* max count of tx datagrams */
 	if ((ctx->tx_max_datagrams == 0) ||
 			(ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
 		ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
 
-	/* verify maximum size of received NTB in bytes */
-	if (ctx->rx_max < USB_CDC_NCM_NTB_MIN_IN_SIZE) {
-		dev_dbg(&dev->intf->dev, "Using min receive length=%d\n",
-			USB_CDC_NCM_NTB_MIN_IN_SIZE);
-		ctx->rx_max = USB_CDC_NCM_NTB_MIN_IN_SIZE;
-	}
+	/* set up maximum NDP size */
+	ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp16) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe16);
 
-	if (ctx->rx_max > CDC_NCM_NTB_MAX_SIZE_RX) {
-		dev_dbg(&dev->intf->dev, "Using default maximum receive length=%d\n",
-			CDC_NCM_NTB_MAX_SIZE_RX);
-		ctx->rx_max = CDC_NCM_NTB_MAX_SIZE_RX;
-	}
+	/* initial coalescing timer interval */
+	ctx->timer_interval = CDC_NCM_TIMER_INTERVAL_USEC * NSEC_PER_USEC;
 
-	/* inform device about NTB input size changes */
-	if (ctx->rx_max != le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize)) {
-		__le32 dwNtbInMaxSize = cpu_to_le32(ctx->rx_max);
+	return 0;
+}
 
-		err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
-				       USB_TYPE_CLASS | USB_DIR_OUT
-				       | USB_RECIP_INTERFACE,
-				       0, iface_no, &dwNtbInMaxSize, 4);
-		if (err < 0)
-			dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
+/* set a new max datagram size */
+static void cdc_ncm_set_dgram_size(struct usbnet *dev, int new_size)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
+	__le16 max_datagram_size;
+	u16 mbim_mtu;
+	int err;
+
+	/* set default based on descriptors */
+	ctx->max_datagram_size = clamp_t(u32, new_size,
+					 cdc_ncm_min_dgram_size(dev),
+					 CDC_NCM_MAX_DATAGRAM_SIZE);
+
+	/* inform the device about the selected Max Datagram Size? */
+	if (!(cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE))
+		goto out;
+
+	/* read current mtu value from device */
+	err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
+			      USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
+			      0, iface_no, &max_datagram_size, 2);
+	if (err < 0) {
+		dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
+		goto out;
 	}
 
-	/* verify maximum size of transmitted NTB in bytes */
-	if (ctx->tx_max > CDC_NCM_NTB_MAX_SIZE_TX) {
-		dev_dbg(&dev->intf->dev, "Using default maximum transmit length=%d\n",
-			CDC_NCM_NTB_MAX_SIZE_TX);
-		ctx->tx_max = CDC_NCM_NTB_MAX_SIZE_TX;
+	if (le16_to_cpu(max_datagram_size) == ctx->max_datagram_size)
+		goto out;
+
+	max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
+	err = usbnet_write_cmd(dev, USB_CDC_SET_MAX_DATAGRAM_SIZE,
+			       USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
+			       0, iface_no, &max_datagram_size, 2);
+	if (err < 0)
+		dev_dbg(&dev->intf->dev, "SET_MAX_DATAGRAM_SIZE failed\n");
+
+out:
+	/* set MTU to max supported by the device if necessary */
+	dev->net->mtu = min_t(int, dev->net->mtu, ctx->max_datagram_size - cdc_ncm_eth_hlen(dev));
+
+	/* do not exceed operater preferred MTU */
+	if (ctx->mbim_extended_desc) {
+		mbim_mtu = le16_to_cpu(ctx->mbim_extended_desc->wMTU);
+		if (mbim_mtu != 0 && mbim_mtu < dev->net->mtu)
+			dev->net->mtu = mbim_mtu;
 	}
+}
+
+static void cdc_ncm_fix_modulus(struct usbnet *dev)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	u32 val;
 
 	/*
 	 * verify that the structure alignment is:
@@ -199,68 +600,31 @@ static int cdc_ncm_setup(struct usbnet *dev)
 	}
 
 	/* adjust TX-remainder according to NCM specification. */
-	ctx->tx_remainder = ((ctx->tx_remainder - eth_hlen) &
+	ctx->tx_remainder = ((ctx->tx_remainder - cdc_ncm_eth_hlen(dev)) &
 			     (ctx->tx_modulus - 1));
+}
 
-	/* additional configuration */
-
-	/* set CRC Mode */
-	if (flags & USB_CDC_NCM_NCAP_CRC_MODE) {
-		err = usbnet_write_cmd(dev, USB_CDC_SET_CRC_MODE,
-				       USB_TYPE_CLASS | USB_DIR_OUT
-				       | USB_RECIP_INTERFACE,
-				       USB_CDC_NCM_CRC_NOT_APPENDED,
-				       iface_no, NULL, 0);
-		if (err < 0)
-			dev_dbg(&dev->intf->dev, "Setting CRC mode off failed\n");
-	}
-
-	/* set NTB format, if both formats are supported */
-	if (ntb_fmt_supported & USB_CDC_NCM_NTH32_SIGN) {
-		err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
-				       USB_TYPE_CLASS | USB_DIR_OUT
-				       | USB_RECIP_INTERFACE,
-				       USB_CDC_NCM_NTB16_FORMAT,
-				       iface_no, NULL, 0);
-		if (err < 0)
-			dev_dbg(&dev->intf->dev, "Setting NTB format to 16-bit failed\n");
-	}
-
-	/* inform the device about the selected Max Datagram Size */
-	if (!(flags & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE))
-		goto out;
-
-	/* read current mtu value from device */
-	err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
-			      USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
-			      0, iface_no, &max_datagram_size, 2);
-	if (err < 0) {
-		dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
-		goto out;
-	}
-
-	if (le16_to_cpu(max_datagram_size) == ctx->max_datagram_size)
-		goto out;
+static int cdc_ncm_setup(struct usbnet *dev)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	u32 def_rx, def_tx;
 
-	max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
-	err = usbnet_write_cmd(dev, USB_CDC_SET_MAX_DATAGRAM_SIZE,
-			       USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
-			       0, iface_no, &max_datagram_size, 2);
-	if (err < 0)
-		dev_dbg(&dev->intf->dev, "SET_MAX_DATAGRAM_SIZE failed\n");
+	/* be conservative when selecting intial buffer size to
+	 * increase the number of hosts this will work for
+	 */
+	def_rx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_RX,
+		       le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
+	def_tx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_TX,
+		       le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
 
-out:
-	/* set MTU to max supported by the device if necessary */
-	if (dev->net->mtu > ctx->max_datagram_size - eth_hlen)
-		dev->net->mtu = ctx->max_datagram_size - eth_hlen;
+	/* clamp rx_max and tx_max and inform device */
+	cdc_ncm_update_rxtx_max(dev, def_rx, def_tx);
 
-	/* do not exceed operater preferred MTU */
-	if (ctx->mbim_extended_desc) {
-		mbim_mtu = le16_to_cpu(ctx->mbim_extended_desc->wMTU);
-		if (mbim_mtu != 0 && mbim_mtu < dev->net->mtu)
-			dev->net->mtu = mbim_mtu;
-	}
+	/* sanitize the modulus and remainder values */
+	cdc_ncm_fix_modulus(dev);
 
+	/* set max datagram size */
+	cdc_ncm_set_dgram_size(dev, cdc_ncm_max_dgram_size(dev));
 	return 0;
 }
 
@@ -424,10 +788,21 @@ advance:
 	}
 
 	/* check if we got everything */
-	if (!ctx->data || (!ctx->mbim_desc && !ctx->ether_desc)) {
-		dev_dbg(&intf->dev, "CDC descriptors missing\n");
+	if (!ctx->data) {
+		dev_dbg(&intf->dev, "CDC Union missing and no IAD found\n");
 		goto error;
 	}
+	if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
+		if (!ctx->mbim_desc) {
+			dev_dbg(&intf->dev, "MBIM functional descriptor missing\n");
+			goto error;
+		}
+	} else {
+		if (!ctx->ether_desc || !ctx->func_desc) {
+			dev_dbg(&intf->dev, "NCM or ECM functional descriptors missing\n");
+			goto error;
+		}
+	}
 
 	/* claim data interface, if different from control */
 	if (ctx->data != ctx->control) {
@@ -447,8 +822,8 @@ advance:
 		goto error2;
 	}
 
-	/* initialize data interface */
-	if (cdc_ncm_setup(dev))
+	/* initialize basic device settings */
+	if (cdc_ncm_init(dev))
 		goto error2;
 
 	/* configure data interface */
@@ -477,18 +852,14 @@ advance:
 		dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
 	}
 
-	/* usbnet use these values for sizing tx/rx queues */
-	dev->hard_mtu = ctx->tx_max;
-	dev->rx_urb_size = ctx->rx_max;
+	/* finish setting up the device specific data */
+	cdc_ncm_setup(dev);
 
-	/* cdc_ncm_setup will override dwNtbOutMaxSize if it is
-	 * outside the sane range. Adding a pad byte here if necessary
-	 * simplifies the handling in cdc_ncm_fill_tx_frame, making
-	 * tx_max always represent the real skb max size.
-	 */
-	if (ctx->tx_max != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
-	    ctx->tx_max % usb_maxpacket(dev->udev, dev->out, 1) == 0)
-		ctx->tx_max++;
+	/* override ethtool_ops */
+	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
+
+	/* add our sysfs attrs */
+	dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;
 
 	return 0;
 
@@ -541,10 +912,10 @@ void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
 }
 EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
 
-/* Select the MBIM altsetting iff it is preferred and available,
- * returning the number of the corresponding data interface altsetting
+/* Return the number of the MBIM control interface altsetting iff it
+ * is preferred and available,
  */
-u8 cdc_ncm_select_altsetting(struct usbnet *dev, struct usb_interface *intf)
+u8 cdc_ncm_select_altsetting(struct usb_interface *intf)
 {
 	struct usb_host_interface *alt;
 
@@ -563,15 +934,15 @@ u8 cdc_ncm_select_altsetting(struct usbnet *dev, struct usb_interface *intf)
 	 *   the rules given in section 6 (USB Device Model) of this
 	 *   specification."
 	 */
-	if (prefer_mbim && intf->num_altsetting == 2) {
+	if (intf->num_altsetting < 2)
+		return intf->cur_altsetting->desc.bAlternateSetting;
+
+	if (prefer_mbim) {
 		alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
-		if (alt && cdc_ncm_comm_intf_is_mbim(alt) &&
-		    !usb_set_interface(dev->udev,
-				       intf->cur_altsetting->desc.bInterfaceNumber,
-				       CDC_NCM_COMM_ALTSETTING_MBIM))
-			return CDC_NCM_DATA_ALTSETTING_MBIM;
+		if (alt && cdc_ncm_comm_intf_is_mbim(alt))
+			return CDC_NCM_COMM_ALTSETTING_MBIM;
 	}
-	return CDC_NCM_DATA_ALTSETTING_NCM;
+	return CDC_NCM_COMM_ALTSETTING_NCM;
 }
 EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
 
@@ -580,12 +951,11 @@ static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
 	int ret;
 
 	/* MBIM backwards compatible function? */
-	cdc_ncm_select_altsetting(dev, intf);
-	if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
+	if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
 		return -ENODEV;
 
-	/* NCM data altsetting is always 1 */
-	ret = cdc_ncm_bind_common(dev, intf, 1);
+	/* The NCM data altsetting is fixed */
+	ret = cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM);
 
 	/*
 	 * We should get an event when network connection is "connected" or
@@ -628,7 +998,7 @@ static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp(struct cdc_ncm_ctx *ctx, struct sk_
 	cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_max);
 
 	/* verify that there is room for the NDP and the datagram (reserve) */
-	if ((ctx->tx_max - skb->len - reserve) < CDC_NCM_NDP_SIZE)
+	if ((ctx->tx_max - skb->len - reserve) < ctx->max_ndp_size)
 		return NULL;
 
 	/* link to it */
@@ -638,7 +1008,7 @@ static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp(struct cdc_ncm_ctx *ctx, struct sk_
 		nth16->wNdpIndex = cpu_to_le16(skb->len);
 
 	/* push a new empty NDP */
-	ndp16 = (struct usb_cdc_ncm_ndp16 *)memset(skb_put(skb, CDC_NCM_NDP_SIZE), 0, CDC_NCM_NDP_SIZE);
+	ndp16 = (struct usb_cdc_ncm_ndp16 *)memset(skb_put(skb, ctx->max_ndp_size), 0, ctx->max_ndp_size);
 	ndp16->dwSignature = sign;
 	ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) + sizeof(struct usb_cdc_ncm_dpe16));
 	return ndp16;
@@ -683,6 +1053,9 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
 
 		/* count total number of frames in this NTB */
 		ctx->tx_curr_frame_num = 0;
+
+		/* recent payload counter for this skb_out */
+		ctx->tx_curr_frame_payload = 0;
 	}
 
 	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
@@ -720,6 +1093,7 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
 				ctx->tx_rem_sign = sign;
 				skb = NULL;
 				ready2send = 1;
+				ctx->tx_reason_ntb_full++;	/* count reason for transmitting */
 			}
 			break;
 		}
@@ -733,12 +1107,14 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
 		ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
 		ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
 		memcpy(skb_put(skb_out, skb->len), skb->data, skb->len);
+		ctx->tx_curr_frame_payload += skb->len;	/* count real tx payload data */
 		dev_kfree_skb_any(skb);
 		skb = NULL;
 
 		/* send now if this NDP is full */
 		if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
 			ready2send = 1;
+			ctx->tx_reason_ndp_full++;	/* count reason for transmitting */
 			break;
 		}
 	}
@@ -758,7 +1134,7 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
 		ctx->tx_curr_skb = skb_out;
 		goto exit_no_skb;
 
-	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0)) {
+	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0) && (ctx->timer_interval > 0)) {
 		/* wait for more frames */
 		/* push variables */
 		ctx->tx_curr_skb = skb_out;
@@ -768,11 +1144,13 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
 		goto exit_no_skb;
 
 	} else {
+		if (n == ctx->tx_max_datagrams)
+			ctx->tx_reason_max_datagram++;	/* count reason for transmitting */
 		/* frame goes out */
 		/* variables will be reset at next call */
 	}
 
-	/* If collected data size is less or equal CDC_NCM_MIN_TX_PKT
+	/* If collected data size is less or equal ctx->min_tx_pkt
 	 * bytes, we send buffers as it is. If we get more data, it
 	 * would be more efficient for USB HS mobile device with DMA
 	 * engine to receive a full size NTB, than canceling DMA
@@ -782,7 +1160,7 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
 	 * a ZLP after full sized NTBs.
 	 */
 	if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
-	    skb_out->len > CDC_NCM_MIN_TX_PKT)
+	    skb_out->len > ctx->min_tx_pkt)
 		memset(skb_put(skb_out, ctx->tx_max - skb_out->len), 0,
 		       ctx->tx_max - skb_out->len);
 	else if (skb_out->len < ctx->tx_max && (skb_out->len % dev->maxpacket) == 0)
@@ -795,11 +1173,22 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
 	/* return skb */
 	ctx->tx_curr_skb = NULL;
 	dev->net->stats.tx_packets += ctx->tx_curr_frame_num;
+
+	/* keep private stats: framing overhead and number of NTBs */
+	ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
+	ctx->tx_ntbs++;
+
+	/* usbnet has already counted all the framing overhead.
+	 * Adjust the stats so that the tx_bytes counter show real
+	 * payload data instead.
+	 */
+	dev->net->stats.tx_bytes -= skb_out->len - ctx->tx_curr_frame_payload;
+
 	return skb_out;
 
 exit_no_skb:
-	/* Start timer, if there is a remaining skb */
-	if (ctx->tx_curr_skb != NULL)
+	/* Start timer, if there is a remaining non-empty skb */
+	if (ctx->tx_curr_skb != NULL && n > 0)
 		cdc_ncm_tx_timeout_start(ctx);
 	return NULL;
 }
@@ -810,7 +1199,7 @@ static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
 	/* start timer, if not already started */
 	if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
 		hrtimer_start(&ctx->tx_timer,
-				ktime_set(0, CDC_NCM_TIMER_INTERVAL),
+				ktime_set(0, ctx->timer_interval),
 				HRTIMER_MODE_REL);
 }
 
@@ -835,6 +1224,7 @@ static void cdc_ncm_txpath_bh(unsigned long param)
 		cdc_ncm_tx_timeout_start(ctx);
 		spin_unlock_bh(&ctx->mtx);
 	} else if (dev->net != NULL) {
+		ctx->tx_reason_timeout++;	/* count reason for transmitting */
 		spin_unlock_bh(&ctx->mtx);
 		netif_tx_lock_bh(dev->net);
 		usbnet_start_xmit(NULL, dev->net);
@@ -970,6 +1360,7 @@ int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
 	struct usb_cdc_ncm_dpe16 *dpe16;
 	int ndpoffset;
 	int loopcount = 50; /* arbitrary max preventing infinite loop */
+	u32 payload = 0;
 
 	ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
 	if (ndpoffset < 0)
@@ -1015,13 +1406,13 @@ next_ndp:
 			break;
 
 		} else {
-			skb = skb_clone(skb_in, GFP_ATOMIC);
+			/* create a fresh copy to reduce truesize */
+			skb = netdev_alloc_skb_ip_align(dev->net,  len);
 			if (!skb)
 				goto error;
-			skb->len = len;
-			skb->data = ((u8 *)skb_in->data) + offset;
-			skb_set_tail_pointer(skb, len);
+			memcpy(skb_put(skb, len), skb_in->data + offset, len);
 			usbnet_skb_return(dev, skb);
+			payload += len;	/* count payload bytes in this NTB */
 		}
 	}
 err_ndp:
@@ -1030,6 +1421,10 @@ err_ndp:
 	if (ndpoffset && loopcount--)
 		goto next_ndp;
 
+	/* update stats */
+	ctx->rx_overhead += skb_in->len - payload;
+	ctx->rx_ntbs++;
+
 	return 1;
 error:
 	return 0;
@@ -1049,14 +1444,14 @@ cdc_ncm_speed_change(struct usbnet *dev,
 	 */
 	if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
 		netif_info(dev, link, dev->net,
-		       "%u mbit/s downlink %u mbit/s uplink\n",
-		       (unsigned int)(rx_speed / 1000000U),
-		       (unsigned int)(tx_speed / 1000000U));
+			   "%u mbit/s downlink %u mbit/s uplink\n",
+			   (unsigned int)(rx_speed / 1000000U),
+			   (unsigned int)(tx_speed / 1000000U));
 	} else {
 		netif_info(dev, link, dev->net,
-		       "%u kbit/s downlink %u kbit/s uplink\n",
-		       (unsigned int)(rx_speed / 1000U),
-		       (unsigned int)(tx_speed / 1000U));
+			   "%u kbit/s downlink %u kbit/s uplink\n",
+			   (unsigned int)(rx_speed / 1000U),
+			   (unsigned int)(tx_speed / 1000U));
 	}
 }
 
@@ -1086,11 +1481,10 @@ static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
 		 */
-		ctx->connected = le16_to_cpu(event->wValue);
 		netif_info(dev, link, dev->net,
 			   "network connection: %sconnected\n",
-			   ctx->connected ? "" : "dis");
-		usbnet_link_change(dev, ctx->connected, 0);
+			   !!event->wValue ? "" : "dis");
+		usbnet_link_change(dev, !!event->wValue, 0);
 		break;
 
 	case USB_CDC_NOTIFY_SPEED_CHANGE:
@@ -1110,23 +1504,11 @@ static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
 	}
 }
 
-static int cdc_ncm_check_connect(struct usbnet *dev)
-{
-	struct cdc_ncm_ctx *ctx;
-
-	ctx = (struct cdc_ncm_ctx *)dev->data[0];
-	if (ctx == NULL)
-		return 1;	/* disconnected */
-
-	return !ctx->connected;
-}
-
 static const struct driver_info cdc_ncm_info = {
 	.description = "CDC NCM",
 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET,
 	.bind = cdc_ncm_bind,
 	.unbind = cdc_ncm_unbind,
-	.check_connect = cdc_ncm_check_connect,
 	.manage_power = usbnet_manage_power,
 	.status = cdc_ncm_status,
 	.rx_fixup = cdc_ncm_rx_fixup,
@@ -1140,7 +1522,6 @@ static const struct driver_info wwan_info = {
 			| FLAG_WWAN,
 	.bind = cdc_ncm_bind,
 	.unbind = cdc_ncm_unbind,
-	.check_connect = cdc_ncm_check_connect,
 	.manage_power = usbnet_manage_power,
 	.status = cdc_ncm_status,
 	.rx_fixup = cdc_ncm_rx_fixup,
@@ -1154,7 +1535,6 @@ static const struct driver_info wwan_noarp_info = {
 			| FLAG_WWAN | FLAG_NOARP,
 	.bind = cdc_ncm_bind,
 	.unbind = cdc_ncm_unbind,
-	.check_connect = cdc_ncm_check_connect,
 	.manage_power = usbnet_manage_power,
 	.status = cdc_ncm_status,
 	.rx_fixup = cdc_ncm_rx_fixup,