[PATCH 1/2] usbnet: changes for upcoming cdc_ncm driver

[PATCH 1/2] usbnet: changes for upcoming cdc_ncm driver

[Alexey Orishko]

Signed-off-by: Alexey Orishko <alexey.orishko-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>
---
Changes:
drivers/net/usb/usbnet.c:
- the procedure of counting packets in usbnet was updated due to the
 accumulating of IP packets in the CDC NCM driver
- no short packets sent for cdc_ncm driver
include/linux/usb/usbnet.h:
- a new flag to indicate driver's capability to accumulate IP packets in one
 skb before sending them (Tx direction)

 drivers/net/usb/usbnet.c   |   45 ++++++++++++++++++++++++++++++-------------
 include/linux/usb/usbnet.h |    6 +++++
 2 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index c04d49e..ac1a66e 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -391,14 +391,19 @@ static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 		goto error;
 	// else network stack removes extra byte if we forced a short packet
 
-	if (skb->len)
-		usbnet_skb_return (dev, skb);
-	else {
-		netif_dbg(dev, rx_err, dev->net, "drop\n");
-error:
-		dev->net->stats.rx_errors++;
-		skb_queue_tail (&dev->done, skb);
+	if (skb->len) {
+		/* all data was already cloned inside NCM driver */
+		if (dev->driver_info->flags & FLAG_MULTI_PACKET)
+			dev_kfree_skb_any(skb);
+		else
+			usbnet_skb_return(dev, skb);
+		return;
 	}
+
+	netif_dbg(dev, rx_err, dev->net, "drop\n");
+error:
+	dev->net->stats.rx_errors++;
+	skb_queue_tail(&dev->done, skb);
 }
 
 /*-------------------------------------------------------------------------*/
@@ -971,7 +976,8 @@ static void tx_complete (struct urb *urb)
 	struct usbnet		*dev = entry->dev;
 
 	if (urb->status == 0) {
-		dev->net->stats.tx_packets++;
+		if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
+			dev->net->stats.tx_packets++;
 		dev->net->stats.tx_bytes += entry->length;
 	} else {
 		dev->net->stats.tx_errors++;
@@ -1044,8 +1050,13 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
 	if (info->tx_fixup) {
 		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
 		if (!skb) {
-			netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
-			goto drop;
+			if (netif_msg_tx_err(dev)) {
+				netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
+				goto drop;
+			} else {
+				/* cdc_ncm collected packet; waits for more */
+				goto not_drop;
+			}
 		}
 	}
 	length = skb->len;
@@ -1067,13 +1078,18 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
 	/* don't assume the hardware handles USB_ZERO_PACKET
 	 * NOTE:  strictly conforming cdc-ether devices should expect
 	 * the ZLP here, but ignore the one-byte packet.
+	 * NOTE2: CDC NCM specification is different from CDC ECM when
+	 * handling ZLP/short packets, so cdc_ncm driver will make short
+	 * packet itself if needed.
 	 */
 	if (length % dev->maxpacket == 0) {
 		if (!(info->flags & FLAG_SEND_ZLP)) {
-			urb->transfer_buffer_length++;
-			if (skb_tailroom(skb)) {
-				skb->data[skb->len] = 0;
-				__skb_put(skb, 1);
+			if (!(info->flags & FLAG_MULTI_PACKET)) {
+				urb->transfer_buffer_length++;
+				if (skb_tailroom(skb)) {
+					skb->data[skb->len] = 0;
+					__skb_put(skb, 1);
+				}
 			}
 		} else
 			urb->transfer_flags |= URB_ZERO_PACKET;
@@ -1122,6 +1138,7 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
 		netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
 drop:
 		dev->net->stats.tx_dropped++;
+not_drop:
 		if (skb)
 			dev_kfree_skb_any (skb);
 		usb_free_urb (urb);
diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index 7ae27a4..f2842cb 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -97,6 +97,12 @@ struct driver_info {
 
 #define FLAG_LINK_INTR	0x0800		/* updates link (carrier) status */
 
+/*
+ * Indicates to usbnet, that USB driver accumulates multiple IP packets before
+ * sending them. Affects statistic (counters) and short packet handling.
+ */
+#define FLAG_MULTI_PACKET	0x1000
+
 	/* init device ... can sleep, or cause probe() failure */
 	int	(*bind)(struct usbnet *, struct usb_interface *);
 
-- 
1.7.0.4

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[PATCH 2/2] USB CDC NCM host driver

[Alexey Orishko]

The driver implementation is based on USB-IF Network Control Model
(NCM) specification, revision 1.0.
The initial version of the driver supports 16-bits NTB only.

Signed-off-by: Alexey Orishko <alexey.orishko@stericsson.com>
---
Changes:
drivers/net/usb/cdc_ncm.c:
- intial submission of the CDC NCM host driver;
- verified on Intel 32/64 bit, Intel Atom, ST-Ericsson U8500 (ARM)
- throughput measured over 100 Mbits duplex;
- driver supports 16-bit NTB format only, but it is more than enought for
  transfers up to 64K;
- driver can handle up to 32 datagrams in received NTB;
- timer is used to collect several packets in Tx direction

drivers/net/usb/Kconfig:
- a new entry to compile CDC NCM host driver
drivers/net/usb/Makefile:
- a new entry to compile CDC NCM host driver

 drivers/net/usb/Kconfig   |   19 +
 drivers/net/usb/Makefile  |    1 +
 drivers/net/usb/cdc_ncm.c | 1224 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1244 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/usb/cdc_ncm.c

diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
index 52ffabe..6f600cc 100644
--- a/drivers/net/usb/Kconfig
+++ b/drivers/net/usb/Kconfig
@@ -196,6 +196,25 @@ config USB_NET_CDC_EEM
 	  IEEE 802 "local assignment" bit is set in the address, a "usbX"
 	  name is used instead.
 
+config USB_NET_CDC_NCM
+	tristate "CDC NCM support"
+	depends on USB_USBNET
+	default y
+	help
+	  This driver provides support for CDC NCM (Network Control Model
+	  Device USB Class Specification). The CDC NCM specification is
+	  available from <http://www.usb.org/>.
+
+	  Say "y" to link the driver statically, or "m" to build a
+	  dynamically linked module.
+
+	  This driver should work with at least the following devices:
+	    * ST-Ericsson M700 LTE FDD/TDD Mobile Broadband Modem (ref. design)
+	    * ST-Ericsson M5730 HSPA+ Mobile Broadband Modem (reference design)
+	    * ST-Ericsson M570 HSPA+ Mobile Broadband Modem (reference design)
+	    * ST-Ericsson M343 HSPA Mobile Broadband Modem (reference design)
+	    * Ericsson F5521gw Mobile Broadband Module
+
 config USB_NET_DM9601
 	tristate "Davicom DM9601 based USB 1.1 10/100 ethernet devices"
 	depends on USB_USBNET
diff --git a/drivers/net/usb/Makefile b/drivers/net/usb/Makefile
index a19b025..cac1703 100644
--- a/drivers/net/usb/Makefile
+++ b/drivers/net/usb/Makefile
@@ -26,4 +26,5 @@ obj-$(CONFIG_USB_CDC_PHONET)	+= cdc-phonet.o
 obj-$(CONFIG_USB_IPHETH)	+= ipheth.o
 obj-$(CONFIG_USB_SIERRA_NET)	+= sierra_net.o
 obj-$(CONFIG_USB_NET_CX82310_ETH)	+= cx82310_eth.o
+obj-$(CONFIG_USB_NET_CDC_NCM)	+= cdc_ncm.o
 
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
new file mode 100644
index 0000000..80755cd
--- /dev/null
+++ b/drivers/net/usb/cdc_ncm.c
@@ -0,0 +1,1224 @@
+/*
+ * cdc_ncm.c
+ *
+ * Copyright (C) ST-Ericsson 2010
+ * Contact: Alexey Orishko <alexey.orishko@stericsson.com>
+ * Original author: Hans Petter Selasky <hans.petter.selasky@stericsson.com>
+ *
+ * USB Host Driver for Network Control Model (NCM)
+ * http://www.usb.org/developers/devclass_docs/NCM10.zip
+ *
+ * The NCM encoding, decoding and initialization logic
+ * derives from FreeBSD 8.x. if_cdce.c and if_cdcereg.h
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose this file to be licensed under the terms
+ * of the GNU General Public License (GPL) Version 2 or the 2-clause
+ * BSD license listed below:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/ctype.h>
+#include <linux/ethtool.h>
+#include <linux/workqueue.h>
+#include <linux/mii.h>
+#include <linux/crc32.h>
+#include <linux/usb.h>
+#include <linux/version.h>
+#include <linux/timer.h>
+#include <linux/spinlock.h>
+#include <linux/atomic.h>
+#include <linux/usb/usbnet.h>
+#include <linux/usb/cdc.h>
+
+#define	DRIVER_VERSION				"23-Nov-2010"
+
+/* CDC NCM subclass 3.2.1 */
+#define USB_CDC_NCM_NDP16_LENGTH_MIN		0x10
+
+/* Maximum NTB length */
+#define	CDC_NCM_NTB_MAX_SIZE_TX			16384	/* bytes */
+#define	CDC_NCM_NTB_MAX_SIZE_RX			16384	/* bytes */
+
+/* Minimum value for MaxDatagramSize, ch. 6.2.9 */
+#define	CDC_NCM_MIN_DATAGRAM_SIZE		1514	/* bytes */
+
+#define	CDC_NCM_MIN_TX_PKT			512	/* bytes */
+
+/* Default value for MaxDatagramSize */
+#define	CDC_NCM_MAX_DATAGRAM_SIZE		2048	/* bytes */
+
+/*
+ * Maximum amount of datagrams in NCM Datagram Pointer Table, not counting
+ * the last NULL entry. Any additional datagrams in NTB would be discarded.
+ */
+#define	CDC_NCM_DPT_DATAGRAMS_MAX		32
+
+/* Restart the timer, if amount of datagrams is less than given value */
+#define	CDC_NCM_RESTART_TIMER_DATAGRAM_CNT	3
+
+/*
+ * We need to align the beginning of the IP packet (not the Ethernet framing).
+ * The following macro aligns the given offset to the given remainder
+ * and modulus, which must be power of two.
+ */
+#define	CDC_NCM_ALIGN(rem, offset, mod)	\
+	((long)(((long)(rem)) - ((long)((-(long)(offset)) & (-(long)(mod))))))
+
+/* The following macro defines the minimum header space */
+#define	CDC_NCM_MIN_HDR_SIZE \
+	(sizeof(struct usb_cdc_ncm_nth16) + sizeof(struct usb_cdc_ncm_ndp16) + \
+	(CDC_NCM_DPT_DATAGRAMS_MAX + 1) * sizeof(struct usb_cdc_ncm_dpe16))
+
+struct connection_speed_change {
+	__le32	USBitRate; /* holds 3GPP downlink value, bits per second */
+	__le32	DSBitRate; /* holds 3GPP uplink value, bits per second */
+} __attribute__ ((packed));
+
+struct cdc_ncm_data {
+	struct usb_cdc_ncm_nth16 nth16;
+	struct usb_cdc_ncm_ndp16 ndp16;
+	struct usb_cdc_ncm_dpe16 dpe16[CDC_NCM_DPT_DATAGRAMS_MAX + 1];
+};
+
+struct cdc_ncm_ctx {
+	struct cdc_ncm_data rx_ncm;
+	struct cdc_ncm_data tx_ncm;
+	struct usb_cdc_ncm_ntb_parameters ncm_parm;
+	struct timer_list tx_timer;
+
+	const struct usb_cdc_ncm_desc *func_desc;
+	const struct usb_cdc_header_desc *header_desc;
+	const struct usb_cdc_union_desc *union_desc;
+	const struct usb_cdc_ether_desc *ether_desc;
+
+	struct net_device *netdev;
+	struct usb_device *udev;
+	struct usb_host_endpoint *in_ep;
+	struct usb_host_endpoint *out_ep;
+	struct usb_host_endpoint *status_ep;
+	struct usb_interface *intf;
+	struct usb_interface *control;
+	struct usb_interface *data;
+
+	struct sk_buff *tx_curr_skb;
+	struct sk_buff *tx_rem_skb;
+
+	spinlock_t mtx;
+
+	u32 tx_timer_pending;
+	u32 tx_curr_offset;
+	u32 tx_curr_last_offset;
+	u32 tx_curr_frame_num;
+	u32 rx_speed;
+	u32 tx_speed;
+	u32 rx_max;
+	u32 tx_max;
+	u32 max_datagram_size;
+	u16 tx_max_datagrams;
+	u16 tx_remainder;
+	u16 tx_modulus;
+	u16 tx_ndp_modulus;
+	u16 tx_seq;
+	u16 connected;
+	u8 data_claimed;
+	u8 control_claimed;
+};
+
+static void cdc_ncm_tx_timeout(unsigned long arg);
+static const struct driver_info cdc_ncm_info;
+static struct usb_driver cdc_ncm_driver;
+static struct ethtool_ops cdc_ncm_ethtool_ops;
+
+static const struct usb_device_id cdc_devs[] = {
+	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
+		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
+		.driver_info = (unsigned long)&cdc_ncm_info,
+	},
+	{
+	},
+};
+
+MODULE_DEVICE_TABLE(usb, cdc_devs);
+
+static void
+cdc_ncm_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *info)
+{
+	struct usbnet *dev = netdev_priv(net);
+
+	strncpy(info->driver, dev->driver_name, sizeof(info->driver));
+	strncpy(info->version, DRIVER_VERSION, sizeof(info->version));
+	strncpy(info->fw_version, dev->driver_info->description,
+		sizeof(info->fw_version));
+	usb_make_path(dev->udev, info->bus_info, sizeof(info->bus_info));
+}
+
+static int
+cdc_ncm_do_request(struct cdc_ncm_ctx *ctx, struct usb_cdc_notification *req,
+		   void *data, u16 flags, u16 *actlen, u16 timeout)
+{
+	int err;
+
+	err = usb_control_msg(ctx->udev, (req->bmRequestType & USB_DIR_IN) ?
+				usb_rcvctrlpipe(ctx->udev, 0) :
+				usb_sndctrlpipe(ctx->udev, 0),
+				req->bNotificationType, req->bmRequestType,
+				req->wValue,
+				req->wIndex, data,
+				req->wLength, timeout);
+
+	if (err < 0) {
+		if (actlen)
+			*actlen = 0;
+		return err;
+	}
+
+	if (actlen)
+		*actlen = err;
+
+	return 0;
+}
+
+static u8 cdc_ncm_setup(struct cdc_ncm_ctx *ctx)
+{
+	struct usb_cdc_notification req;
+	u32 val;
+	__le16 max_datagram_size;
+	u8 flags;
+	u8 iface_no;
+	int err;
+
+	iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
+
+	req.bmRequestType = USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE;
+	req.bNotificationType = USB_CDC_GET_NTB_PARAMETERS;
+	req.wValue = 0;
+	req.wIndex = cpu_to_le16(iface_no);
+	req.wLength = cpu_to_le16(sizeof(ctx->ncm_parm));
+
+	err = cdc_ncm_do_request(ctx, &req, &ctx->ncm_parm, 0, NULL, 1000);
+	if (err) {
+		pr_debug("failed GET_NTB_PARAMETERS\n");
+		return 1;
+	}
+
+	/* read correct set of parameters according to device mode */
+	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);
+	ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
+	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
+
+	if (ctx->func_desc != NULL)
+		flags = ctx->func_desc->bmNetworkCapabilities;
+	else
+		flags = 0;
+
+	pr_debug("dwNtbInMaxSize=%u dwNtbOutMaxSize=%u "
+		 "wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u "
+		 "wNdpOutAlignment=%u flags=0x%x\n",
+		 ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
+		 ctx->tx_ndp_modulus, flags);
+
+	/* max count of tx datagrams without terminating NULL entry */
+	ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
+
+	/* verify maximum size of received NTB in bytes */
+	if ((ctx->rx_max <
+	    (CDC_NCM_MIN_HDR_SIZE + CDC_NCM_MIN_DATAGRAM_SIZE)) ||
+	    (ctx->rx_max > CDC_NCM_NTB_MAX_SIZE_RX)) {
+		pr_debug("Using default maximum receive length=%d\n",
+						CDC_NCM_NTB_MAX_SIZE_RX);
+		ctx->rx_max = CDC_NCM_NTB_MAX_SIZE_RX;
+	}
+
+	/* verify maximum size of transmitted NTB in bytes */
+	if ((ctx->tx_max <
+	    (CDC_NCM_MIN_HDR_SIZE + CDC_NCM_MIN_DATAGRAM_SIZE)) ||
+	    (ctx->tx_max > CDC_NCM_NTB_MAX_SIZE_TX)) {
+		pr_debug("Using default maximum transmit length=%d\n",
+						CDC_NCM_NTB_MAX_SIZE_TX);
+		ctx->tx_max = CDC_NCM_NTB_MAX_SIZE_TX;
+	}
+
+	/*
+	 * verify that the structure alignment is:
+	 * - power of two
+	 * - not greater than the maximum transmit length
+	 * - not less than four bytes
+	 */
+	val = ctx->tx_ndp_modulus;
+
+	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
+	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
+		pr_debug("Using default alignment: 4 bytes\n");
+		ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
+	}
+
+	/*
+	 * verify that the payload alignment is:
+	 * - power of two
+	 * - not greater than the maximum transmit length
+	 * - not less than four bytes
+	 */
+	val = ctx->tx_modulus;
+
+	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
+	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
+		pr_debug("Using default transmit modulus: 4 bytes\n");
+		ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
+	}
+
+	/* verify the payload remainder */
+	if (ctx->tx_remainder >= ctx->tx_modulus) {
+		pr_debug("Using default transmit remainder: 0 bytes\n");
+		ctx->tx_remainder = 0;
+	}
+
+	/* adjust TX-remainder according to NCM specification. */
+	ctx->tx_remainder = ((ctx->tx_remainder - ETH_HLEN) &
+						(ctx->tx_modulus - 1));
+
+	/* additional configuration */
+
+	/* set CRC Mode */
+	req.bmRequestType = USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE;
+	req.bNotificationType = USB_CDC_SET_CRC_MODE;
+	req.wValue = cpu_to_le16(USB_CDC_NCM_CRC_NOT_APPENDED);
+	req.wIndex = cpu_to_le16(iface_no);
+	req.wLength = 0;
+
+	err = cdc_ncm_do_request(ctx, &req, NULL, 0, NULL, 1000);
+	if (err)
+		pr_debug("Setting CRC mode off failed\n");
+
+	/* set NTB format */
+	req.bmRequestType = USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE;
+	req.bNotificationType = USB_CDC_SET_NTB_FORMAT;
+	req.wValue = cpu_to_le16(USB_CDC_NCM_NTB16_FORMAT);
+	req.wIndex = cpu_to_le16(iface_no);
+	req.wLength = 0;
+
+	err = cdc_ncm_do_request(ctx, &req, NULL, 0, NULL, 1000);
+	if (err)
+		pr_debug("Setting NTB format to 16-bit failed\n");
+
+	/* set Max Datagram Size (MTU) */
+	req.bmRequestType = USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE;
+	req.bNotificationType = USB_CDC_GET_MAX_DATAGRAM_SIZE;
+	req.wValue = 0;
+	req.wIndex = cpu_to_le16(iface_no);
+	req.wLength = cpu_to_le16(2);
+
+	err = cdc_ncm_do_request(ctx, &req, &max_datagram_size, 0, NULL, 1000);
+	if (err) {
+		pr_debug(" GET_MAX_DATAGRAM_SIZE failed, using size=%u\n",
+			 CDC_NCM_MIN_DATAGRAM_SIZE);
+		/* use default */
+		ctx->max_datagram_size = CDC_NCM_MIN_DATAGRAM_SIZE;
+	} else {
+		ctx->max_datagram_size = le16_to_cpu(max_datagram_size);
+
+		if (ctx->max_datagram_size < CDC_NCM_MIN_DATAGRAM_SIZE)
+			ctx->max_datagram_size = CDC_NCM_MIN_DATAGRAM_SIZE;
+		else if (ctx->max_datagram_size > CDC_NCM_MAX_DATAGRAM_SIZE)
+			ctx->max_datagram_size = CDC_NCM_MAX_DATAGRAM_SIZE;
+	}
+
+	if (ctx->netdev->mtu != (ctx->max_datagram_size - ETH_HLEN))
+		ctx->netdev->mtu = ctx->max_datagram_size - ETH_HLEN;
+
+	return 0;
+}
+
+static void
+cdc_ncm_find_endpoints(struct cdc_ncm_ctx *ctx, struct usb_interface *intf)
+{
+	struct usb_host_endpoint *e;
+	u8 ep;
+
+	for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
+
+		e = intf->cur_altsetting->endpoint + ep;
+		switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
+		case USB_ENDPOINT_XFER_INT:
+			if (usb_endpoint_dir_in(&e->desc)) {
+				if (ctx->status_ep == NULL)
+					ctx->status_ep = e;
+			}
+			break;
+
+		case USB_ENDPOINT_XFER_BULK:
+			if (usb_endpoint_dir_in(&e->desc)) {
+				if (ctx->in_ep == NULL)
+					ctx->in_ep = e;
+			} else {
+				if (ctx->out_ep == NULL)
+					ctx->out_ep = e;
+			}
+			break;
+
+		default:
+			break;
+		}
+	}
+}
+
+static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
+{
+	if (ctx == NULL)
+		return;
+
+	del_timer_sync(&ctx->tx_timer);
+
+	if (ctx->data_claimed) {
+		usb_set_intfdata(ctx->data, NULL);
+		usb_driver_release_interface(driver_of(ctx->intf), ctx->data);
+	}
+
+	if (ctx->control_claimed) {
+		usb_set_intfdata(ctx->control, NULL);
+		usb_driver_release_interface(driver_of(ctx->intf),
+								ctx->control);
+	}
+
+	if (ctx->tx_rem_skb != NULL) {
+		dev_kfree_skb_any(ctx->tx_rem_skb);
+		ctx->tx_rem_skb = NULL;
+	}
+
+	if (ctx->tx_curr_skb != NULL) {
+		dev_kfree_skb_any(ctx->tx_curr_skb);
+		ctx->tx_curr_skb = NULL;
+	}
+
+	kfree(ctx);
+}
+
+static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+	struct cdc_ncm_ctx *ctx;
+	struct usb_driver *driver;
+	u8 *buf;
+	int len;
+	int temp;
+	u8 iface_no;
+
+	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+	if (ctx == NULL)
+		goto error;
+
+	memset(ctx, 0, sizeof(*ctx));
+
+	init_timer(&ctx->tx_timer);
+	spin_lock_init(&ctx->mtx);
+	ctx->netdev = dev->net;
+
+	/* store ctx pointer in device data field */
+	dev->data[0] = (unsigned long)ctx;
+
+	/* get some pointers */
+	driver = driver_of(intf);
+	buf = intf->cur_altsetting->extra;
+	len = intf->cur_altsetting->extralen;
+
+	ctx->udev = dev->udev;
+	ctx->intf = intf;
+
+	/* parse through descriptors associated with control interface */
+	while ((len > 0) && (buf[0] > 2) && (buf[0] <= len)) {
+
+		if (buf[1] != USB_DT_CS_INTERFACE)
+			goto advance;
+
+		switch (buf[2]) {
+		case USB_CDC_UNION_TYPE:
+			if (buf[0] < sizeof(*(ctx->union_desc)))
+				break;
+
+			ctx->union_desc =
+					(const struct usb_cdc_union_desc *)buf;
+
+			ctx->control = usb_ifnum_to_if(dev->udev,
+					ctx->union_desc->bMasterInterface0);
+			ctx->data = usb_ifnum_to_if(dev->udev,
+					ctx->union_desc->bSlaveInterface0);
+			break;
+
+		case USB_CDC_ETHERNET_TYPE:
+			if (buf[0] < sizeof(*(ctx->ether_desc)))
+				break;
+
+			ctx->ether_desc =
+					(const struct usb_cdc_ether_desc *)buf;
+
+			dev->hard_mtu =
+				le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
+
+			if (dev->hard_mtu <
+			    (CDC_NCM_MIN_DATAGRAM_SIZE - ETH_HLEN))
+				dev->hard_mtu =
+					CDC_NCM_MIN_DATAGRAM_SIZE - ETH_HLEN;
+
+			else if (dev->hard_mtu >
+				 (CDC_NCM_MAX_DATAGRAM_SIZE - ETH_HLEN))
+				dev->hard_mtu =
+					CDC_NCM_MAX_DATAGRAM_SIZE - ETH_HLEN;
+			break;
+
+		case USB_CDC_NCM_TYPE:
+			if (buf[0] < sizeof(*(ctx->func_desc)))
+				break;
+
+			ctx->func_desc = (const struct usb_cdc_ncm_desc *)buf;
+			break;
+
+		default:
+			break;
+		}
+advance:
+		/* advance to next descriptor */
+		temp = buf[0];
+		buf += temp;
+		len -= temp;
+	}
+
+	/* check if we got everything */
+	if ((ctx->control == NULL) || (ctx->data == NULL) ||
+	    (ctx->ether_desc == NULL))
+		goto error;
+
+	/* claim interfaces, if any */
+	if (ctx->data != intf) {
+		temp = usb_driver_claim_interface(driver, ctx->data, dev);
+		if (temp)
+			goto error;
+		ctx->data_claimed = 1;
+	}
+
+	if (ctx->control != intf) {
+		temp = usb_driver_claim_interface(driver, ctx->control, dev);
+		if (temp)
+			goto error;
+		ctx->control_claimed = 1;
+	}
+
+	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
+
+	/* reset data interface */
+	temp = usb_set_interface(dev->udev, iface_no, 0);
+	if (temp)
+		goto error;
+
+	/* initialize data interface */
+	if (cdc_ncm_setup(ctx))
+		goto error;
+
+	/* configure data interface */
+	temp = usb_set_interface(dev->udev, iface_no, 1);
+	if (temp)
+		goto error;
+
+	cdc_ncm_find_endpoints(ctx, ctx->data);
+	cdc_ncm_find_endpoints(ctx, ctx->control);
+
+	if ((ctx->in_ep == NULL) || (ctx->out_ep == NULL) ||
+	    (ctx->status_ep == NULL))
+		goto error;
+
+	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
+
+	usb_set_intfdata(ctx->data, dev);
+	usb_set_intfdata(ctx->control, dev);
+	usb_set_intfdata(ctx->intf, dev);
+
+	temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
+	if (temp)
+		goto error;
+
+	dev_info(&dev->udev->dev, "MAC-Address: "
+				"0x%02x:0x%02x:0x%02x:0x%02x:0x%02x:0x%02x\n",
+				dev->net->dev_addr[0], dev->net->dev_addr[1],
+				dev->net->dev_addr[2], dev->net->dev_addr[3],
+				dev->net->dev_addr[4], dev->net->dev_addr[5]);
+
+	dev->in = usb_rcvbulkpipe(dev->udev,
+		ctx->in_ep->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
+	dev->out = usb_sndbulkpipe(dev->udev,
+		ctx->out_ep->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
+	dev->status = ctx->status_ep;
+	dev->rx_urb_size = ctx->rx_max;
+
+	/*
+	 * We should get an event when network connection is "connected" or
+	 * "disconnected". Set network connection in "disconnected" state
+	 * (carrier is OFF) during attach, so the IP network stack does not
+	 * start IPv6 negotiation and more.
+	 */
+	netif_carrier_off(dev->net);
+	ctx->tx_speed = ctx->rx_speed = 0;
+	return 0;
+
+error:
+	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
+	dev->data[0] = 0;
+	dev_info(&dev->udev->dev, "Descriptor failure\n");
+	return -ENODEV;
+}
+
+static void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	struct usb_driver *driver;
+
+	if (ctx == NULL)
+		return;		/* no setup */
+
+	driver = driver_of(intf);
+
+	usb_set_intfdata(ctx->data, NULL);
+	usb_set_intfdata(ctx->control, NULL);
+	usb_set_intfdata(ctx->intf, NULL);
+
+	/* release interfaces, if any */
+	if (ctx->data_claimed) {
+		usb_driver_release_interface(driver, ctx->data);
+		ctx->data_claimed = 0;
+	}
+
+	if (ctx->control_claimed) {
+		usb_driver_release_interface(driver, ctx->control);
+		ctx->control_claimed = 0;
+	}
+
+	cdc_ncm_free(ctx);
+}
+
+static void cdc_ncm_zero_fill(u8 *ptr, u32 first, u32 end, u32 max)
+{
+	if (first >= max)
+		return;
+	if (first >= end)
+		return;
+	if (end > max)
+		end = max;
+	memset(ptr + first, 0, end - first);
+}
+
+static struct sk_buff *
+cdc_ncm_fill_tx_frame(struct cdc_ncm_ctx *ctx, struct sk_buff *skb)
+{
+	struct sk_buff *skb_out;
+	u32 rem;
+	u32 offset;
+	u32 last_offset;
+	u16 n = 0;
+	u8 timeout = 0;
+
+	/* if there is a remaining skb, it gets priority */
+	if (skb != NULL)
+		swap(skb, ctx->tx_rem_skb);
+	else
+		timeout = 1;
+
+	/*
+	 * +----------------+
+	 * | skb_out        |
+	 * +----------------+
+	 *           ^ offset
+	 *        ^ last_offset
+	 */
+
+	/* check if we are resuming an OUT skb */
+	if (ctx->tx_curr_skb != NULL) {
+		/* pop variables */
+		skb_out = ctx->tx_curr_skb;
+		offset = ctx->tx_curr_offset;
+		last_offset = ctx->tx_curr_last_offset;
+		n = ctx->tx_curr_frame_num;
+
+	} else {
+		/* reset variables */
+		skb_out = alloc_skb(ctx->tx_max, GFP_ATOMIC);
+		if (skb_out == NULL) {
+			if (skb != NULL) {
+				dev_kfree_skb_any(skb);
+				ctx->netdev->stats.tx_dropped++;
+			}
+			goto exit_no_skb;
+		}
+
+		/* make room for NTH and NDP */
+		offset = CDC_NCM_ALIGN(0, sizeof(struct usb_cdc_ncm_nth16),
+							ctx->tx_ndp_modulus) +
+					sizeof(struct usb_cdc_ncm_ndp16) +
+					(ctx->tx_max_datagrams + 1) *
+					sizeof(struct usb_cdc_ncm_dpe16);
+
+		/* store last valid offset before alignment */
+		last_offset = offset;
+		/* align first Datagram offset correctly */
+		offset = CDC_NCM_ALIGN(ctx->tx_remainder, offset,
+							ctx->tx_modulus);
+		/* zero buffer till the first IP datagram */
+		cdc_ncm_zero_fill(skb_out->data, 0, offset, offset);
+		n = 0;
+		ctx->tx_curr_frame_num = 0;
+	}
+
+	for (; n < ctx->tx_max_datagrams; n++) {
+		/* check if end of transmit buffer is reached */
+		if (offset >= ctx->tx_max)
+			break;
+
+		/* compute maximum buffer size */
+		rem = ctx->tx_max - offset;
+
+		if (skb == NULL) {
+			skb = ctx->tx_rem_skb;
+			ctx->tx_rem_skb = NULL;
+
+			/* check for end of skb */
+			if (skb == NULL)
+				break;
+		}
+
+		if (skb->len > rem) {
+			if (n == 0) {
+				/* won't fit, MTU problem? */
+				dev_kfree_skb_any(skb);
+				skb = NULL;
+				ctx->netdev->stats.tx_dropped++;
+			} else {
+				/* no room for skb - store for later */
+				if (ctx->tx_rem_skb != NULL) {
+					dev_kfree_skb_any(ctx->tx_rem_skb);
+					ctx->netdev->stats.tx_dropped++;
+				}
+				ctx->tx_rem_skb = skb;
+				skb = NULL;
+
+				/* loop one more time */
+				timeout = 1;
+			}
+			break;
+		}
+
+		memcpy(((u8 *)skb_out->data) + offset, skb->data, skb->len);
+
+		ctx->tx_ncm.dpe16[n].wDatagramLength = cpu_to_le16(skb->len);
+		ctx->tx_ncm.dpe16[n].wDatagramIndex = cpu_to_le16(offset);
+
+		/* update offset */
+		offset += skb->len;
+
+		/* store last valid offset before alignment */
+		last_offset = offset;
+
+		/* align offset correctly */
+		offset = CDC_NCM_ALIGN(ctx->tx_remainder, offset,
+							ctx->tx_modulus);
+
+		/* zero padding */
+		cdc_ncm_zero_fill(skb_out->data, last_offset, offset,
+								ctx->tx_max);
+		dev_kfree_skb_any(skb);
+		skb = NULL;
+	}
+
+	/* free up any dangling skb */
+	if (skb != NULL) {
+		dev_kfree_skb_any(skb);
+		skb = NULL;
+		ctx->netdev->stats.tx_dropped++;
+	}
+
+	ctx->tx_curr_frame_num = n;
+
+	if (n == 0) {
+		/* wait for more frames */
+		/* push variables */
+		ctx->tx_curr_skb = skb_out;
+		ctx->tx_curr_offset = offset;
+		ctx->tx_curr_last_offset = last_offset;
+		goto exit_no_skb;
+
+	} else if ((n < ctx->tx_max_datagrams) && (timeout == 0)) {
+		/* wait for more frames */
+		/* push variables */
+		ctx->tx_curr_skb = skb_out;
+		ctx->tx_curr_offset = offset;
+		ctx->tx_curr_last_offset = last_offset;
+		/* set the pending count */
+		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
+			ctx->tx_timer_pending = 2;
+		goto exit_no_skb;
+
+	} else {
+		/* frame goes out */
+		/* variables will be reset at next call */
+	}
+
+	/* check for overflow */
+	if (last_offset > ctx->tx_max)
+		last_offset = ctx->tx_max;
+
+	/* revert offset */
+	offset = last_offset;
+
+	/*
+	 * If collected data size is less or equal CDC_NCM_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 transfer and receiving a short packet.
+	 */
+	if (offset > CDC_NCM_MIN_TX_PKT)
+		offset = ctx->tx_max;
+
+	/* final zero padding */
+	cdc_ncm_zero_fill(skb_out->data, last_offset, offset, ctx->tx_max);
+
+	/* store last offset */
+	last_offset = offset;
+
+	if ((last_offset < ctx->tx_max) && ((last_offset %
+			le16_to_cpu(ctx->out_ep->desc.wMaxPacketSize)) == 0)) {
+		/* force short packet */
+		*(((u8 *)skb_out->data) + last_offset) = 0;
+		last_offset++;
+	}
+
+	/* zero the rest of the DPEs plus the last NULL entry */
+	for (; n <= CDC_NCM_DPT_DATAGRAMS_MAX; n++) {
+		ctx->tx_ncm.dpe16[n].wDatagramLength = 0;
+		ctx->tx_ncm.dpe16[n].wDatagramIndex = 0;
+	}
+
+	/* fill out 16-bit NTB header */
+	ctx->tx_ncm.nth16.dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
+	ctx->tx_ncm.nth16.wHeaderLength =
+					cpu_to_le16(sizeof(ctx->tx_ncm.nth16));
+	ctx->tx_ncm.nth16.wSequence = cpu_to_le16(ctx->tx_seq);
+	ctx->tx_ncm.nth16.wBlockLength = cpu_to_le16(last_offset);
+	ctx->tx_ncm.nth16.wFpIndex = CDC_NCM_ALIGN(0,
+					sizeof(struct usb_cdc_ncm_nth16),
+					ctx->tx_ndp_modulus);
+
+	memcpy(skb_out->data, &(ctx->tx_ncm.nth16), sizeof(ctx->tx_ncm.nth16));
+	ctx->tx_seq++;
+
+	/* fill out 16-bit NDP table */
+	ctx->tx_ncm.ndp16.dwSignature =
+				cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN);
+	rem = sizeof(ctx->tx_ncm.ndp16) + ((ctx->tx_curr_frame_num + 1) *
+					sizeof(struct usb_cdc_ncm_dpe16));
+	ctx->tx_ncm.ndp16.wLength = cpu_to_le16(rem);
+	ctx->tx_ncm.ndp16.wNextFpIndex = 0; /* reserved */
+
+	memcpy(((u8 *)skb_out->data) + ctx->tx_ncm.nth16.wFpIndex,
+						&(ctx->tx_ncm.ndp16),
+						sizeof(ctx->tx_ncm.ndp16));
+
+	memcpy(((u8 *)skb_out->data) + ctx->tx_ncm.nth16.wFpIndex +
+					sizeof(ctx->tx_ncm.ndp16),
+					&(ctx->tx_ncm.dpe16),
+					(ctx->tx_curr_frame_num + 1) *
+					sizeof(struct usb_cdc_ncm_dpe16));
+
+	/* set frame length */
+	skb_put(skb_out, last_offset);
+
+	/* return skb */
+	ctx->tx_curr_skb = NULL;
+	return skb_out;
+
+exit_no_skb:
+	return NULL;
+}
+
+static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
+{
+	/* start timer, if not already started */
+	if (timer_pending(&ctx->tx_timer) == 0) {
+		ctx->tx_timer.function = &cdc_ncm_tx_timeout;
+		ctx->tx_timer.data = (unsigned long)ctx;
+		ctx->tx_timer.expires = jiffies + ((HZ + 999) / 1000);
+		add_timer(&ctx->tx_timer);
+	}
+}
+
+static void cdc_ncm_tx_timeout(unsigned long arg)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)arg;
+	u8 restart;
+
+	spin_lock(&ctx->mtx);
+	if (ctx->tx_timer_pending != 0) {
+		ctx->tx_timer_pending--;
+		restart = 1;
+	} else
+		restart = 0;
+
+	spin_unlock(&ctx->mtx);
+
+	if (restart)
+		cdc_ncm_tx_timeout_start(ctx);
+	else if (ctx->netdev != NULL)
+		usbnet_start_xmit(NULL, ctx->netdev);
+}
+
+static struct sk_buff *
+cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
+{
+	struct sk_buff *skb_out;
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	u8 need_timer = 0;
+
+	/*
+	 * The Ethernet API we are using does not support transmitting
+	 * multiple Ethernet frames in a single call. This driver will
+	 * accumulate multiple Ethernet frames and send out a larger
+	 * USB frame when the USB buffer is full or when a single jiffies
+	 * timeout happens.
+	 */
+	if (ctx == NULL)
+		goto error;
+
+	spin_lock(&ctx->mtx);
+	skb_out = cdc_ncm_fill_tx_frame(ctx, skb);
+	if (ctx->tx_curr_skb != NULL)
+		need_timer = 1;
+	spin_unlock(&ctx->mtx);
+
+	/* Start timer, if there is a remaining skb */
+	if (need_timer)
+		cdc_ncm_tx_timeout_start(ctx);
+
+	if (skb_out)
+		dev->net->stats.tx_packets += ctx->tx_curr_frame_num;
+	return skb_out;
+
+error:
+	if (skb != NULL)
+		dev_kfree_skb_any(skb);
+
+	return NULL;
+}
+
+static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
+{
+	struct sk_buff *skb;
+	struct cdc_ncm_ctx *ctx;
+	int sumlen;
+	int actlen;
+	int temp;
+	int nframes;
+	int x;
+	int offset;
+
+	ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	if (ctx == NULL)
+		goto error;
+
+	actlen = skb_in->len;
+	sumlen = CDC_NCM_NTB_MAX_SIZE_RX;
+
+	if (actlen < (sizeof(ctx->rx_ncm.nth16) + sizeof(ctx->rx_ncm.ndp16))) {
+		pr_debug("frame too short\n");
+		goto error;
+	}
+
+	memcpy(&(ctx->rx_ncm.nth16), ((u8 *)skb_in->data),
+						sizeof(ctx->rx_ncm.nth16));
+
+	if (le32_to_cpu(ctx->rx_ncm.nth16.dwSignature) !=
+	    USB_CDC_NCM_NTH16_SIGN) {
+		pr_debug("invalid NTH16 signature <%u>\n",
+			 le32_to_cpu(ctx->rx_ncm.nth16.dwSignature));
+		goto error;
+	}
+
+	temp = le16_to_cpu(ctx->rx_ncm.nth16.wBlockLength);
+	if (temp > sumlen) {
+		pr_debug("unsupported NTB block length %u/%u\n", temp, sumlen);
+		goto error;
+	}
+
+	temp = le16_to_cpu(ctx->rx_ncm.nth16.wFpIndex);
+	if ((temp + sizeof(ctx->rx_ncm.ndp16)) > actlen) {
+		pr_debug("invalid DPT16 index\n");
+		goto error;
+	}
+
+	memcpy(&(ctx->rx_ncm.ndp16), ((u8 *)skb_in->data) + temp,
+						sizeof(ctx->rx_ncm.ndp16));
+
+	if (le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature) !=
+	    USB_CDC_NCM_NDP16_NOCRC_SIGN) {
+		pr_debug("invalid DPT16 signature <%u>\n",
+			 le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature));
+		goto error;
+	}
+
+	if (le16_to_cpu(ctx->rx_ncm.ndp16.wLength) <
+	    USB_CDC_NCM_NDP16_LENGTH_MIN) {
+		pr_debug("invalid DPT16 length <%u>\n",
+			 le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature));
+		goto error;
+	}
+
+	nframes = ((le16_to_cpu(ctx->rx_ncm.ndp16.wLength) -
+					sizeof(struct usb_cdc_ncm_ndp16)) /
+					sizeof(struct usb_cdc_ncm_dpe16));
+	nframes--; /* we process NDP entries except for the last one */
+
+	pr_debug("nframes = %u\n", nframes);
+
+	temp += sizeof(ctx->rx_ncm.ndp16);
+
+	if ((temp + nframes * (sizeof(struct usb_cdc_ncm_dpe16))) > actlen) {
+		pr_debug("Invalid nframes = %d\n", nframes);
+		goto error;
+	}
+
+	if (nframes > CDC_NCM_DPT_DATAGRAMS_MAX) {
+		pr_debug("Truncating number of frames from %u to %u\n",
+					nframes, CDC_NCM_DPT_DATAGRAMS_MAX);
+		nframes = CDC_NCM_DPT_DATAGRAMS_MAX;
+	}
+
+	memcpy(&(ctx->rx_ncm.dpe16), ((u8 *)skb_in->data) + temp,
+				nframes * (sizeof(struct usb_cdc_ncm_dpe16)));
+
+	for (x = 0; x < nframes; x++) {
+		offset = le16_to_cpu(ctx->rx_ncm.dpe16[x].wDatagramIndex);
+		temp = le16_to_cpu(ctx->rx_ncm.dpe16[x].wDatagramLength);
+
+		/*
+		 * CDC NCM ch. 3.7
+		 * All entries after first NULL entry are to be ignored
+		 */
+		if ((offset == 0) || (temp == 0)) {
+			if (!x)
+				goto error; /* empty NTB */
+			break;
+		}
+
+		/* sanity checking */
+		if (((offset + temp) > actlen) ||
+		    (temp > CDC_NCM_MAX_DATAGRAM_SIZE) || (temp < ETH_HLEN)) {
+			pr_debug("invalid frame detected (ignored)"
+				"offset[%u]=%u, length=%u, skb=%p\n",
+							x, offset, temp, skb);
+			if (!x)
+				goto error;
+			break;
+
+		} else {
+			skb = skb_clone(skb_in, GFP_ATOMIC);
+			skb->len = temp;
+			skb->data = ((u8 *)skb_in->data) + offset;
+			skb_set_tail_pointer(skb, temp);
+			usbnet_skb_return(dev, skb);
+		}
+	}
+	return 1;
+error:
+	return 0;
+}
+
+static void
+cdc_ncm_speed_change(struct cdc_ncm_ctx *ctx,
+		     struct connection_speed_change *data)
+{
+	uint32_t rx_speed = le32_to_cpu(data->USBitRate);
+	uint32_t tx_speed = le32_to_cpu(data->DSBitRate);
+
+	/*
+	 * Currently the USB-NET API does not support reporting the actual
+	 * device speed. Do print it instead.
+	 */
+	if ((tx_speed != ctx->tx_speed) || (rx_speed != ctx->rx_speed)) {
+		ctx->tx_speed = tx_speed;
+		ctx->rx_speed = rx_speed;
+
+		if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
+			printk(KERN_INFO KBUILD_MODNAME
+				": %s: %u mbit/s downlink "
+				"%u mbit/s uplink\n",
+				ctx->netdev->name,
+				(unsigned int)(rx_speed / 1000000U),
+				(unsigned int)(tx_speed / 1000000U));
+		} else {
+			printk(KERN_INFO KBUILD_MODNAME
+				": %s: %u kbit/s downlink "
+				"%u kbit/s uplink\n",
+				ctx->netdev->name,
+				(unsigned int)(rx_speed / 1000U),
+				(unsigned int)(tx_speed / 1000U));
+		}
+	}
+}
+
+static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
+{
+	struct cdc_ncm_ctx *ctx;
+	struct usb_cdc_notification *event;
+
+	ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+	if (urb->actual_length < sizeof(*event))
+		return;
+
+	/* test for split data in 8-byte chunks */
+	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
+		cdc_ncm_speed_change(ctx,
+		      (struct connection_speed_change *)urb->transfer_buffer);
+		return;
+	}
+
+	event = urb->transfer_buffer;
+
+	switch (event->bNotificationType) {
+	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
+		/*
+		 * According to the CDC NCM specification ch.7.1
+		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
+		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
+		 */
+		ctx->connected = event->wValue;
+
+		printk(KERN_INFO KBUILD_MODNAME ": %s: network connection:"
+			" %sconnected\n",
+			ctx->netdev->name, ctx->connected ? "" : "dis");
+
+		if (ctx->connected)
+			netif_carrier_on(dev->net);
+		else {
+			netif_carrier_off(dev->net);
+			ctx->tx_speed = ctx->rx_speed = 0;
+		}
+		break;
+
+	case USB_CDC_NOTIFY_SPEED_CHANGE:
+		if (urb->actual_length <
+		    (sizeof(*event) + sizeof(struct connection_speed_change)))
+			set_bit(EVENT_STS_SPLIT, &dev->flags);
+		else
+			cdc_ncm_speed_change(ctx,
+				(struct connection_speed_change *) &event[1]);
+		break;
+
+	default:
+		dev_err(&dev->udev->dev, "NCM: unexpected "
+			"notification 0x%02x!\n", event->bNotificationType);
+		break;
+	}
+}
+
+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 int
+cdc_ncm_probe(struct usb_interface *udev, const struct usb_device_id *prod)
+{
+	return usbnet_probe(udev, prod);
+}
+
+static void cdc_ncm_disconnect(struct usb_interface *intf)
+{
+	struct usbnet *dev = usb_get_intfdata(intf);
+
+	if (dev == NULL)
+		return;		/* already disconnected */
+
+	usbnet_disconnect(intf);
+}
+
+static int cdc_ncm_manage_power(struct usbnet *dev, int status)
+{
+	dev->intf->needs_remote_wakeup = status;
+	return 0;
+}
+
+static const struct driver_info cdc_ncm_info = {
+	.description = "CDC NCM",
+	.flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET,
+	.bind = cdc_ncm_bind,
+	.unbind = cdc_ncm_unbind,
+	.check_connect = cdc_ncm_check_connect,
+	.manage_power = cdc_ncm_manage_power,
+	.status = cdc_ncm_status,
+	.rx_fixup = cdc_ncm_rx_fixup,
+	.tx_fixup = cdc_ncm_tx_fixup,
+};
+
+static struct usb_driver cdc_ncm_driver = {
+	.name = "cdc_ncm",
+	.id_table = cdc_devs,
+	.probe = cdc_ncm_probe,
+	.disconnect = cdc_ncm_disconnect,
+	.suspend = usbnet_suspend,
+	.resume = usbnet_resume,
+	.supports_autosuspend = 1,
+};
+
+static struct ethtool_ops cdc_ncm_ethtool_ops = {
+	.get_drvinfo = cdc_ncm_get_drvinfo,
+	.get_link = usbnet_get_link,
+	.get_msglevel = usbnet_get_msglevel,
+	.set_msglevel = usbnet_set_msglevel,
+	.get_settings = usbnet_get_settings,
+	.set_settings = usbnet_set_settings,
+	.nway_reset = usbnet_nway_reset,
+};
+
+static int __init cdc_ncm_init(void)
+{
+	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION "\n");
+	return usb_register(&cdc_ncm_driver);
+}
+
+module_init(cdc_ncm_init);
+
+static void __exit cdc_ncm_exit(void)
+{
+	usb_deregister(&cdc_ncm_driver);
+}
+
+module_exit(cdc_ncm_exit);
+
+MODULE_AUTHOR("Hans Petter Selasky");
+MODULE_DESCRIPTION("USB CDC NCM host driver");
+MODULE_LICENSE("Dual BSD/GPL");
-- 
1.7.0.4

RE: [PATCH 1/2] usbnet: changes for upcoming cdc_ncm driver

[Viral Mehta]

Hi,

>Signed-off-by: Alexey Orishko <alexey.orishko-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>
>---
>Changes:
>drivers/net/usb/usbnet.c:
>- the procedure of counting packets in usbnet was updated due to the
 >accumulating of IP packets in the CDC NCM driver
>- no short packets sent for cdc_ncm driver
>include/linux/usb/usbnet.h:
>- a new flag to indicate driver's capability to accumulate IP packets in one
 >skb before sending them (Tx direction)

Feels like good to have these comments in comment log itself (i..e, above Signed-off-by line)
Same for another patch as well.

Viral

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Re: [PATCH 1/2] usbnet: changes for upcoming cdc_ncm driver

[David Brownell]

On Tue, 2010-11-23 at 17:51 +0100, Alexey Orishko wrote:

> -		skb_queue_tail (&dev->done, skb);
> +	if (skb->len) {
> +		/* all data was already cloned inside NCM driver */

Fix this comment.  NCM isn't the only framing policy which un-batches
RX packets ... RNDIS has done so for a number of years already, and
more recently EEM needs it too ... plus at least one hardware driver.

Also, check pending patches, since I seem to recall one that supports
some hardware (SMSC?) that batches, and needed to update the calling
convention you're using here (i.e. the original one).


> +		if (dev->driver_info->flags & FLAG_MULTI_PACKET)

except ... you documented this flag as affecting TX paths not RX...
> +			dev_kfree_skb_any(skb);
> +		else
> +			usbnet_skb_return(dev, skb);
> +		return;
>  	}
> +
> +	netif_dbg(dev, rx_err, dev->net, "drop\n");
> +error:
> +	dev->net->stats.rx_errors++;
> +	skb_queue_tail(&dev->done, skb);
>  }
>  

RE: [PATCH 1/2] usbnet: changes for upcoming cdc_ncm driver

[Alexey ORISHKO]

> -----Original Message-----
> From: Viral Mehta [mailto:Viral.Mehta-oonXi/34qI7c+919tysfdA@public.gmane.org]
> Sent: 23 ноября 2010 г. 18:40
> To: Alexey Orishko; gregkh-l3A5Bk7waGM@public.gmane.org; linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org;
> yauheni.kaliuta-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org; felipe.balbi-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org; Sjur BRENDELAND;
> Alexey ORISHKO
> Subject: RE: [PATCH 1/2] usbnet: changes for upcoming cdc_ncm driver
> 
> Hi,
> 
> >Signed-off-by: Alexey Orishko <alexey.orishko-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>
> >---
> >Changes:
> >drivers/net/usb/usbnet.c:
> >- the procedure of counting packets in usbnet was updated due to the
>  >accumulating of IP packets in the CDC NCM driver
> >- no short packets sent for cdc_ncm driver
> >include/linux/usb/usbnet.h:
> >- a new flag to indicate driver's capability to accumulate IP packets
> in one
>  >skb before sending them (Tx direction)
> 
> Feels like good to have these comments in comment log itself (i..e,
> above Signed-off-by line)
> Same for another patch as well.

No problem, I will repost it with comments above signed-off line

> 
> Viral
> 
> This Email may contain confidential or privileged information for the
> intended recipient (s) If you are not the intended recipient, please do
> not use or disseminate the information, notify the sender and delete it
> from your system.
> 
> ______________________________________________________________________
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RE: [PATCH 1/2] usbnet: changes for upcoming cdc_ncm driver

[Alexey ORISHKO]

Hi David,

> > -		skb_queue_tail (&dev->done, skb);
> > +	if (skb->len) {
> > +		/* all data was already cloned inside NCM driver */
> 
> Fix this comment.  NCM isn't the only framing policy which un-batches
> RX packets ... RNDIS has done so for a number of years already, and
> more recently EEM needs it too ... plus at least one hardware driver.

Will do.

> Also, check pending patches, since I seem to recall one that supports
> some hardware (SMSC?) that batches, and needed to update the calling
> convention you're using here (i.e. the original one).

Patch was based on linux-next git and I don't see any difference from
net-next. Any particular git you'd like me to look at pending patches?

> 
> 
> > +		if (dev->driver_info->flags & FLAG_MULTI_PACKET)
> 
> except ... you documented this flag as affecting TX paths not RX...

This flag carries two purposes:
- help to correct statistic (Tx/Rx counting)
- handle NCM feature to avoid sending short packets in certain
conditions: cdc_ncm driver has to send short packet (or ZLP) only
if data size is not equal to negotiated data size (dwNtbOutMaxSize).

The other option (instead of dedicated flag) would be to add
additional field in the usbnet context structure, which will keep
dwNtbOutMaxSize value (it still would be better to use
dedicated flag in addition to the value). Thus usbnet would possess
the knowledge when ZLP or short packet should be skipped.
By doing this approach we will eliminate a need to generate short
packet inside the driver and use generic code in usbnet.

Could you comment, what would be the preferable way to get it in the
next version of this patch?

Regards,
Alexey