Staging: USB/IP: add client driver

This adds the USB IP client driver

Brian Merrell cleaned up a lot of this code and submitted it for
inclusion.  Greg also did a lot of cleanup.

Signed-off-by: Brian G. Merrell <bgmerrell@novell.com>
Cc: Takahiro Hirofuchi <hirofuchi@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

7 files changed, 2171 insertions, 0 deletions

diff --git a/drivers/staging/usbip/Kconfig b/drivers/staging/usbip/Kconfig
index 37efb5e1bb82..c4d68e1581fc 100644
--- a/drivers/staging/usbip/Kconfig
+++ b/drivers/staging/usbip/Kconfig
@@ -12,3 +12,14 @@ config USB_IP_COMMON
 	  module will be called usbip_common_mod.
 
 	  If unsure, say N.
+
+config USB_IP_VHCI_HCD
+	tristate "USB IP client driver"
+	depends on USB_IP_COMMON
+	default N
+	---help---
+	 This enables the USB IP host controller driver which will
+	 run on the client machine.
+
+	 To compile this driver as a module, choose M here: the
+	 module will be called vhci_hcd.
diff --git a/drivers/staging/usbip/Makefile b/drivers/staging/usbip/Makefile
index ce925caa6083..6ef4c3913f45 100644
--- a/drivers/staging/usbip/Makefile
+++ b/drivers/staging/usbip/Makefile
@@ -1,6 +1,9 @@
 obj-$(CONFIG_USB_IP_COMMON) += usbip_common_mod.o
 usbip_common_mod-objs := usbip_common.o usbip_event.o
 
+obj-$(CONFIG_USB_IP_VHCI_HCD) += vhci-hcd.o
+vhci-hcd-objs := vhci_sysfs.o vhci_tx.o vhci_rx.o vhci_hcd.o
+
 ifeq ($(CONFIG_USB_DEBUG),y)
 	EXTRA_CFLAGS += -DDEBUG
 endif
diff --git a/drivers/staging/usbip/vhci.h b/drivers/staging/usbip/vhci.h
new file mode 100644
index 000000000000..5e375173bbce
--- /dev/null
+++ b/drivers/staging/usbip/vhci.h
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#include <linux/platform_device.h>
+#include "../../usb/core/hcd.h"
+
+
+struct vhci_device {
+	struct usb_device *udev;
+
+	/*
+	 * devid specifies a remote usb device uniquely instead
+	 * of combination of busnum and devnum.
+	 */
+	__u32 devid;
+
+	/* speed of a remote device */
+	enum usb_device_speed speed;
+
+	/*  vhci root-hub port to which this device is attached  */
+	__u32 rhport;
+
+	struct usbip_device ud;
+
+
+	/* lock for the below link lists */
+	spinlock_t priv_lock;
+
+	/* vhci_priv is linked to one of them. */
+	struct list_head priv_tx;
+	struct list_head priv_rx;
+
+	/* vhci_unlink is linked to one of them */
+	struct list_head unlink_tx;
+	struct list_head unlink_rx;
+
+	/* vhci_tx thread sleeps for this queue */
+	wait_queue_head_t waitq_tx;
+};
+
+
+/* urb->hcpriv, use container_of() */
+struct vhci_priv {
+	unsigned long seqnum;
+	struct list_head list;
+
+	struct vhci_device *vdev;
+	struct urb *urb;
+};
+
+
+struct vhci_unlink {
+	/* seqnum of this request */
+	unsigned long seqnum;
+
+	struct list_head list;
+
+	/* seqnum of the unlink target */
+	unsigned long unlink_seqnum;
+};
+
+/*
+ * The number of ports is less than 16 ?
+ * USB_MAXCHILDREN is statically defined to 16 in usb.h.  Its maximum value
+ * would be 31 because the event_bits[1] of struct usb_hub is defined as
+ * unsigned long in hub.h
+ */
+#define VHCI_NPORTS 8
+
+/* for usb_bus.hcpriv */
+struct vhci_hcd {
+	spinlock_t	lock;
+
+	u32	port_status[VHCI_NPORTS];
+
+	unsigned	resuming:1;
+	unsigned long	re_timeout;
+
+	atomic_t seqnum;
+
+	/*
+	 * NOTE:
+	 * wIndex shows the port number and begins from 1.
+	 * But, the index of this array begins from 0.
+	 */
+	struct vhci_device vdev[VHCI_NPORTS];
+
+	/* vhci_device which has not been assiged its address yet */
+	int pending_port;
+};
+
+
+extern struct vhci_hcd *the_controller;
+extern struct attribute_group dev_attr_group;
+
+
+/*-------------------------------------------------------------------------*/
+/* prototype declaration */
+
+/* vhci_hcd.c */
+void rh_port_connect(int rhport, enum usb_device_speed speed);
+void rh_port_disconnect(int rhport);
+void vhci_rx_loop(struct usbip_task *ut);
+void vhci_tx_loop(struct usbip_task *ut);
+
+#define hardware		(&the_controller->pdev.dev)
+
+static inline struct vhci_device *port_to_vdev(__u32 port)
+{
+	return &the_controller->vdev[port];
+}
+
+static inline struct vhci_hcd *hcd_to_vhci(struct usb_hcd *hcd)
+{
+	return (struct vhci_hcd *) (hcd->hcd_priv);
+}
+
+static inline struct usb_hcd *vhci_to_hcd(struct vhci_hcd *vhci)
+{
+	return container_of((void *) vhci, struct usb_hcd, hcd_priv);
+}
+
+static inline struct device *vhci_dev(struct vhci_hcd *vhci)
+{
+	return vhci_to_hcd(vhci)->self.controller;
+}
diff --git a/drivers/staging/usbip/vhci_hcd.c b/drivers/staging/usbip/vhci_hcd.c
new file mode 100644
index 000000000000..5b5a2e348ecb
--- /dev/null
+++ b/drivers/staging/usbip/vhci_hcd.c
@@ -0,0 +1,1275 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+
+#include "usbip_common.h"
+#include "vhci.h"
+
+#define DRIVER_VERSION "1.0"
+#define DRIVER_AUTHOR "Takahiro Hirofuchi"
+#define DRIVER_DESC "Virtual Host Controller Interface Driver for USB/IP"
+#define DRIVER_LICENCE "GPL"
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE(DRIVER_LICENCE);
+
+
+
+/*
+ * TODO
+ *	- update root hub emulation
+ *	- move the emulation code to userland ?
+ *		porting to other operating systems
+ *		minimize kernel code
+ *	- add suspend/resume code
+ *	- clean up everything
+ */
+
+
+/* See usb gadget dummy hcd */
+
+
+static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
+static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
+		u16 wIndex, char *buff, u16 wLength);
+static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
+							gfp_t mem_flags);
+static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
+static int vhci_start(struct usb_hcd *vhci_hcd);
+static void vhci_stop(struct usb_hcd *hcd);
+static int vhci_get_frame_number(struct usb_hcd *hcd);
+
+static const char driver_name[] = "vhci_hcd";
+static const char driver_desc[] = "USB/IP Virtual Host Contoroller";
+
+struct vhci_hcd *the_controller;
+
+static const char *bit_desc[] = {
+	"CONNECTION",		/*0*/
+	"ENABLE",		/*1*/
+	"SUSPEND",		/*2*/
+	"OVER_CURRENT",		/*3*/
+	"RESET",		/*4*/
+	"R5",		/*5*/
+	"R6",		/*6*/
+	"R7",		/*7*/
+	"POWER",		/*8*/
+	"LOWSPEED",		/*9*/
+	"HIGHSPEED",		/*10*/
+	"PORT_TEST",		/*11*/
+	"INDICATOR",		/*12*/
+	"R13",		/*13*/
+	"R14",		/*14*/
+	"R15",		/*15*/
+	"C_CONNECTION",		/*16*/
+	"C_ENABLE",		/*17*/
+	"C_SUSPEND",		/*18*/
+	"C_OVER_CURRENT",	/*19*/
+	"C_RESET",		/*20*/
+	"R21",		/*21*/
+	"R22",		/*22*/
+	"R23",		/*23*/
+	"R24",		/*24*/
+	"R25",		/*25*/
+	"R26",		/*26*/
+	"R27",		/*27*/
+	"R28",		/*28*/
+	"R29",		/*29*/
+	"R30",		/*30*/
+	"R31",		/*31*/
+};
+
+
+static void dump_port_status(u32 status)
+{
+	int i = 0;
+
+	printk(KERN_DEBUG "status %08x:", status);
+	for (i = 0; i < 32; i++) {
+		if (status & (1 << i))
+			printk(" %s", bit_desc[i]);
+	}
+
+	printk("\n");
+}
+
+
+
+void rh_port_connect(int rhport, enum usb_device_speed speed)
+{
+	unsigned long	flags;
+
+	dbg_vhci_rh("rh_port_connect %d\n", rhport);
+
+	spin_lock_irqsave(&the_controller->lock, flags);
+
+	the_controller->port_status[rhport] |= USB_PORT_STAT_CONNECTION
+		| (1 << USB_PORT_FEAT_C_CONNECTION);
+
+	switch (speed) {
+	case USB_SPEED_HIGH:
+		the_controller->port_status[rhport] |= USB_PORT_STAT_HIGH_SPEED;
+		break;
+	case USB_SPEED_LOW:
+		the_controller->port_status[rhport] |= USB_PORT_STAT_LOW_SPEED;
+		break;
+	default:
+		break;
+	}
+
+	/* spin_lock(&the_controller->vdev[rhport].ud.lock);
+	 * the_controller->vdev[rhport].ud.status = VDEV_CONNECT;
+	 * spin_unlock(&the_controller->vdev[rhport].ud.lock); */
+
+	the_controller->pending_port = rhport;
+
+	spin_unlock_irqrestore(&the_controller->lock, flags);
+
+	usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
+}
+
+void rh_port_disconnect(int rhport)
+{
+	unsigned long flags;
+
+	dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
+
+	spin_lock_irqsave(&the_controller->lock, flags);
+	/* stop_activity(dum, driver); */
+	the_controller->port_status[rhport] &= ~USB_PORT_STAT_CONNECTION;
+	the_controller->port_status[rhport] |=
+					(1 << USB_PORT_FEAT_C_CONNECTION);
+
+
+	/* not yet complete the disconnection
+	 * spin_lock(&vdev->ud.lock);
+	 * vdev->ud.status = VHC_ST_DISCONNECT;
+	 * spin_unlock(&vdev->ud.lock); */
+
+	spin_unlock_irqrestore(&the_controller->lock, flags);
+}
+
+
+
+/*----------------------------------------------------------------------*/
+
+#define PORT_C_MASK \
+	((USB_PORT_STAT_C_CONNECTION \
+	  | USB_PORT_STAT_C_ENABLE \
+	  | USB_PORT_STAT_C_SUSPEND \
+	  | USB_PORT_STAT_C_OVERCURRENT \
+	  | USB_PORT_STAT_C_RESET) << 16)
+
+/*
+ * This function is almostly the same as dummy_hcd.c:dummy_hub_status() without
+ * suspend/resume support. But, it is modified to provide multiple ports.
+ *
+ * @buf: a bitmap to show which port status has been changed.
+ *  bit  0: reserved or used for another purpose?
+ *  bit  1: the status of port 0 has been changed.
+ *  bit  2: the status of port 1 has been changed.
+ *  ...
+ *  bit  7: the status of port 6 has been changed.
+ *  bit  8: the status of port 7 has been changed.
+ *  ...
+ *  bit 15: the status of port 14 has been changed.
+ *
+ * So, the maximum number of ports is 31 ( port 0 to port 30) ?
+ *
+ * The return value is the actual transfered length in byte. If nothing has
+ * been changed, return 0. In the case that the number of ports is less than or
+ * equal to 6 (VHCI_NPORTS==7), return 1.
+ *
+ */
+static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
+{
+	struct vhci_hcd	*vhci;
+	unsigned long	flags;
+	int		retval = 0;
+
+	/* the enough buffer is allocated according to USB_MAXCHILDREN */
+	unsigned long	*event_bits = (unsigned long *) buf;
+	int		rhport;
+	int		changed = 0;
+
+
+	*event_bits = 0;
+
+	vhci = hcd_to_vhci(hcd);
+
+	spin_lock_irqsave(&vhci->lock, flags);
+	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+		dbg_vhci_rh("hw accessible flag in on?\n");
+		goto done;
+	}
+
+	/* check pseudo status register for each port */
+	for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
+		if ((vhci->port_status[rhport] & PORT_C_MASK)) {
+			/* The status of a port has been changed, */
+			dbg_vhci_rh("port %d is changed\n", rhport);
+
+			*event_bits |= 1 << (rhport + 1);
+			changed = 1;
+		}
+	}
+
+	uinfo("changed %d\n", changed);
+
+	if (hcd->state == HC_STATE_SUSPENDED)
+		usb_hcd_resume_root_hub(hcd);
+
+	if (changed)
+		retval = 1 + (VHCI_NPORTS / 8);
+	else
+		retval = 0;
+
+done:
+	spin_unlock_irqrestore(&vhci->lock, flags);
+	return retval;
+}
+
+/* See hub_configure in hub.c */
+static inline void hub_descriptor(struct usb_hub_descriptor *desc)
+{
+	memset(desc, 0, sizeof(*desc));
+	desc->bDescriptorType = 0x29;
+	desc->bDescLength = 9;
+	desc->wHubCharacteristics = (__force __u16)
+		(__constant_cpu_to_le16(0x0001));
+	desc->bNbrPorts = VHCI_NPORTS;
+	desc->bitmap[0] = 0xff;
+	desc->bitmap[1] = 0xff;
+}
+
+static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
+			    u16 wIndex, char *buf, u16 wLength)
+{
+	struct vhci_hcd	*dum;
+	int             retval = 0;
+	unsigned long   flags;
+	int		rhport;
+
+	u32 prev_port_status[VHCI_NPORTS];
+
+	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
+		return -ETIMEDOUT;
+
+	/*
+	 * NOTE:
+	 * wIndex shows the port number and begins from 1.
+	 */
+	dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
+								wIndex);
+	if (wIndex > VHCI_NPORTS)
+		printk(KERN_ERR "%s: invalid port number %d\n", __func__, wIndex);
+	rhport = ((__u8)(wIndex & 0x00ff)) - 1;
+
+	dum = hcd_to_vhci(hcd);
+
+	spin_lock_irqsave(&dum->lock, flags);
+
+	/* store old status and compare now and old later */
+	if (dbg_flag_vhci_rh) {
+		int i = 0;
+		for (i = 0; i < VHCI_NPORTS; i++)
+			prev_port_status[i] = dum->port_status[i];
+	}
+
+	switch (typeReq) {
+	case ClearHubFeature:
+		dbg_vhci_rh(" ClearHubFeature\n");
+		break;
+	case ClearPortFeature:
+		switch (wValue) {
+		case USB_PORT_FEAT_SUSPEND:
+			if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
+				/* 20msec signaling */
+				dum->resuming = 1;
+				dum->re_timeout =
+					jiffies + msecs_to_jiffies(20);
+			}
+			break;
+		case USB_PORT_FEAT_POWER:
+			dbg_vhci_rh(" ClearPortFeature: USB_PORT_FEAT_POWER\n");
+			dum->port_status[rhport] = 0;
+			/* dum->address = 0; */
+			/* dum->hdev = 0; */
+			dum->resuming = 0;
+			break;
+		case USB_PORT_FEAT_C_RESET:
+			dbg_vhci_rh(" ClearPortFeature: "
+					"USB_PORT_FEAT_C_RESET\n");
+			switch (dum->vdev[rhport].speed) {
+			case USB_SPEED_HIGH:
+				dum->port_status[rhport] |=
+						USB_PORT_STAT_HIGH_SPEED;
+				break;
+			case USB_SPEED_LOW:
+				dum->port_status[rhport] |=
+						USB_PORT_STAT_LOW_SPEED;
+				break;
+			default:
+				break;
+			}
+		default:
+			dbg_vhci_rh(" ClearPortFeature: default %x\n", wValue);
+			dum->port_status[rhport] &= ~(1 << wValue);
+		}
+		break;
+	case GetHubDescriptor:
+		dbg_vhci_rh(" GetHubDescriptor\n");
+		hub_descriptor((struct usb_hub_descriptor *) buf);
+		break;
+	case GetHubStatus:
+		dbg_vhci_rh(" GetHubStatus\n");
+		*(__le32 *) buf = __constant_cpu_to_le32(0);
+		break;
+	case GetPortStatus:
+		dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
+		if (wIndex > VHCI_NPORTS || wIndex < 1) {
+			printk(KERN_ERR "%s: invalid port number %d\n",
+			       __func__, wIndex);
+			retval = -EPIPE;
+		}
+
+		/* we do no care of resume. */
+
+		/* whoever resets or resumes must GetPortStatus to
+		 * complete it!!
+		 *                                   */
+		if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
+			printk(KERN_ERR "%s: not yet\n", __func__);
+			dum->port_status[rhport] |=
+					(1 << USB_PORT_FEAT_C_SUSPEND);
+			dum->port_status[rhport] &=
+					~(1 << USB_PORT_FEAT_SUSPEND);
+			dum->resuming = 0;
+			dum->re_timeout = 0;
+			/* if (dum->driver && dum->driver->resume) {
+			 *	spin_unlock (&dum->lock);
+			 *	dum->driver->resume (&dum->gadget);
+			 *	spin_lock (&dum->lock);
+			 * } */
+		}
+
+		if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
+				0 && time_after(jiffies, dum->re_timeout)) {
+			dum->port_status[rhport] |=
+						(1 << USB_PORT_FEAT_C_RESET);
+			dum->port_status[rhport] &=
+						~(1 << USB_PORT_FEAT_RESET);
+			dum->re_timeout = 0;
+
+			if (dum->vdev[rhport].ud.status ==
+							VDEV_ST_NOTASSIGNED) {
+				dbg_vhci_rh(" enable rhport %d (status %u)\n",
+						rhport,
+						dum->vdev[rhport].ud.status);
+				dum->port_status[rhport] |=
+							USB_PORT_STAT_ENABLE;
+			}
+#if 0
+			if (dum->driver) {
+
+				dum->port_status[rhport] |=
+							USB_PORT_STAT_ENABLE;
+				/* give it the best speed we agree on */
+				dum->gadget.speed = dum->driver->speed;
+				dum->gadget.ep0->maxpacket = 64;
+				switch (dum->gadget.speed) {
+				case USB_SPEED_HIGH:
+					dum->port_status[rhport] |=
+					USB_PORT_STAT_HIGH_SPEED;
+					break;
+				case USB_SPEED_LOW:
+					dum->gadget.ep0->maxpacket = 8;
+					dum->port_status[rhport] |=
+					USB_PORT_STAT_LOW_SPEED;
+					break;
+				default:
+					dum->gadget.speed = USB_SPEED_FULL;
+					break;
+				}
+			}
+#endif
+
+		}
+		((u16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
+		((u16 *) buf)[1] =
+				cpu_to_le16(dum->port_status[rhport] >> 16);
+
+		dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
+							((u16 *)buf)[1]);
+		break;
+	case SetHubFeature:
+		dbg_vhci_rh(" SetHubFeature\n");
+		retval = -EPIPE;
+		break;
+	case SetPortFeature:
+		switch (wValue) {
+		case USB_PORT_FEAT_SUSPEND:
+			dbg_vhci_rh(" SetPortFeature: "
+					"USB_PORT_FEAT_SUSPEND\n");
+			printk(KERN_ERR "%s: not yet\n", __func__);
+#if 0
+			dum->port_status[rhport] |=
+						(1 << USB_PORT_FEAT_SUSPEND);
+			if (dum->driver->suspend) {
+				spin_unlock(&dum->lock);
+				dum->driver->suspend(&dum->gadget);
+				spin_lock(&dum->lock);
+			}
+#endif
+			break;
+		case USB_PORT_FEAT_RESET:
+			dbg_vhci_rh(" SetPortFeature: USB_PORT_FEAT_RESET\n");
+			/* if it's already running, disconnect first */
+			if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
+				dum->port_status[rhport] &=
+						~(USB_PORT_STAT_ENABLE |
+						  USB_PORT_STAT_LOW_SPEED |
+						  USB_PORT_STAT_HIGH_SPEED);
+#if 0
+				if (dum->driver) {
+					dev_dbg(hardware, "disconnect\n");
+					stop_activity(dum, dum->driver);
+				}
+#endif
+
+				/* FIXME test that code path! */
+			}
+			/* 50msec reset signaling */
+			dum->re_timeout = jiffies + msecs_to_jiffies(50);
+
+			/* FALLTHROUGH */
+		default:
+			dbg_vhci_rh(" SetPortFeature: default %d\n", wValue);
+			dum->port_status[rhport] |= (1 << wValue);
+		}
+		break;
+
+	default:
+		printk(KERN_ERR "%s: default: no such request\n", __func__);
+		/* dev_dbg (hardware,
+		 *		"hub control req%04x v%04x i%04x l%d\n",
+		 *		typeReq, wValue, wIndex, wLength); */
+
+		/* "protocol stall" on error */
+		retval = -EPIPE;
+	}
+
+	if (dbg_flag_vhci_rh) {
+		printk(KERN_DEBUG "port %d\n", rhport);
+		dump_port_status(prev_port_status[rhport]);
+		dump_port_status(dum->port_status[rhport]);
+	}
+	dbg_vhci_rh(" bye\n");
+
+	spin_unlock_irqrestore(&dum->lock, flags);
+
+	return retval;
+}
+
+
+
+/*----------------------------------------------------------------------*/
+
+static struct vhci_device *get_vdev(struct usb_device *udev)
+{
+	int i;
+
+	if (!udev)
+		return NULL;
+
+	for (i = 0; i < VHCI_NPORTS; i++)
+		if (the_controller->vdev[i].udev == udev)
+			return port_to_vdev(i);
+
+	return NULL;
+}
+
+static void vhci_tx_urb(struct urb *urb)
+{
+	struct vhci_device *vdev = get_vdev(urb->dev);
+	struct vhci_priv *priv;
+	unsigned long flag;
+
+	if (!vdev) {
+		err("could not get virtual device");
+		/* BUG(); */
+		return;
+	}
+
+	spin_lock_irqsave(&vdev->priv_lock, flag);
+
+	priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
+	if (!priv) {
+		dev_err(&urb->dev->dev, "malloc vhci_priv\n");
+		spin_unlock_irqrestore(&vdev->priv_lock, flag);
+		usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
+		return;
+	}
+
+	priv->seqnum = atomic_inc_return(&the_controller->seqnum);
+	if (priv->seqnum == 0xffff)
+		uinfo("seqnum max\n");
+
+	priv->vdev = vdev;
+	priv->urb = urb;
+
+	urb->hcpriv = (void *) priv;
+
+
+	list_add_tail(&priv->list, &vdev->priv_tx);
+
+	wake_up(&vdev->waitq_tx);
+	spin_unlock_irqrestore(&vdev->priv_lock, flag);
+}
+
+static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
+			    gfp_t mem_flags)
+{
+	struct device *dev = &urb->dev->dev;
+	int ret = 0;
+	unsigned long flags;
+
+	dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
+		    hcd, urb, mem_flags);
+
+	/* patch to usb_sg_init() is in 2.5.60 */
+	BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
+
+	spin_lock_irqsave(&the_controller->lock, flags);
+
+	/* check HC is active or not */
+	if (!HC_IS_RUNNING(hcd->state)) {
+		dev_err(dev, "HC is not running\n");
+		spin_unlock_irqrestore(&the_controller->lock, flags);
+		return -ENODEV;
+	}
+
+	if (urb->status != -EINPROGRESS) {
+		dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
+		spin_unlock_irqrestore(&the_controller->lock, flags);
+		return urb->status;
+	}
+
+	ret = usb_hcd_link_urb_to_ep(hcd, urb);
+	if (ret)
+		goto no_need_unlink;
+
+	/*
+	 * The enumelation process is as follows;
+	 *
+	 *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
+	 *     to get max packet length of default pipe
+	 *
+	 *  2. Set_Address request to DevAddr(0) EndPoint(0)
+	 *
+	 */
+
+	if (usb_pipedevice(urb->pipe) == 0) {
+		__u8 type = usb_pipetype(urb->pipe);
+		struct usb_ctrlrequest *ctrlreq =
+				(struct usb_ctrlrequest *) urb->setup_packet;
+		struct vhci_device *vdev =
+				port_to_vdev(the_controller->pending_port);
+
+		if (type != PIPE_CONTROL || !ctrlreq) {
+			dev_err(dev, "invalid request to devnum 0\n");
+			ret = EINVAL;
+			goto no_need_xmit;
+		}
+
+		switch (ctrlreq->bRequest) {
+		case USB_REQ_SET_ADDRESS:
+			/* set_address may come when a device is reset */
+			dev_info(dev, "SetAddress Request (%d) to port %d\n",
+				 ctrlreq->wValue, vdev->rhport);
+
+			vdev->udev = urb->dev;
+
+			spin_lock(&vdev->ud.lock);
+			vdev->ud.status = VDEV_ST_USED;
+			spin_unlock(&vdev->ud.lock);
+
+			if (urb->status == -EINPROGRESS) {
+				/* This request is successfully completed. */
+				/* If not -EINPROGRESS, possibly unlinked. */
+				urb->status = 0;
+			}
+
+			goto no_need_xmit;
+
+		case USB_REQ_GET_DESCRIPTOR:
+			if (ctrlreq->wValue == (USB_DT_DEVICE << 8))
+				dbg_vhci_hc("Not yet?: "
+						"Get_Descriptor to device 0 "
+						"(get max pipe size)\n");
+
+			/* FIXME: reference count? (usb_get_dev()) */
+			vdev->udev = urb->dev;
+			goto out;
+
+		default:
+			/* NOT REACHED */
+			dev_err(dev, "invalid request to devnum 0 bRequest %u, "
+				"wValue %u\n", ctrlreq->bRequest,
+				ctrlreq->wValue);
+			ret =  -EINVAL;
+			goto no_need_xmit;
+		}
+
+	}
+
+out:
+	vhci_tx_urb(urb);
+
+	spin_unlock_irqrestore(&the_controller->lock, flags);
+
+	return 0;
+
+no_need_xmit:
+	usb_hcd_unlink_urb_from_ep(hcd, urb);
+no_need_unlink:
+	spin_unlock_irqrestore(&the_controller->lock, flags);
+
+	usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
+
+	return 0;
+}
+
+/*
+ * vhci_rx gives back the urb after receiving the reply of the urb.  If an
+ * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
+ * back its urb. For the driver unlinking the urb, the content of the urb is
+ * not important, but the calling to its completion handler is important; the
+ * completion of unlinking is notified by the completion handler.
+ *
+ *
+ * CLIENT SIDE
+ *
+ * - When vhci_hcd receives RET_SUBMIT,
+ *
+ *	- case 1a). the urb of the pdu is not unlinking.
+ *		- normal case
+ *		=> just give back the urb
+ *
+ *	- case 1b). the urb of the pdu is unlinking.
+ *		- usbip.ko will return a reply of the unlinking request.
+ *		=> give back the urb now and go to case 2b).
+ *
+ * - When vhci_hcd receives RET_UNLINK,
+ *
+ *	- case 2a). a submit request is still pending in vhci_hcd.
+ *		- urb was really pending in usbip.ko and urb_unlink_urb() was
+ *		  completed there.
+ *		=> free a pending submit request
+ *		=> notify unlink completeness by giving back the urb
+ *
+ *	- case 2b). a submit request is *not* pending in vhci_hcd.
+ *		- urb was already given back to the core driver.
+ *		=> do not give back the urb
+ *
+ *
+ * SERVER SIDE
+ *
+ * - When usbip receives CMD_UNLINK,
+ *
+ *	- case 3a). the urb of the unlink request is now in submission.
+ *		=> do usb_unlink_urb().
+ *		=> after the unlink is completed, send RET_UNLINK.
+ *
+ *	- case 3b). the urb of the unlink request is not in submission.
+ *		- may be already completed or never be received
+ *		=> send RET_UNLINK
+ *
+ */
+static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
+{
+	unsigned long flags;
+	struct vhci_priv *priv;
+	struct vhci_device *vdev;
+
+	uinfo("vhci_hcd: dequeue a urb %p\n", urb);
+
+
+	spin_lock_irqsave(&the_controller->lock, flags);
+
+	priv = urb->hcpriv;
+	if (!priv) {
+		/* URB was never linked! or will be soon given back by
+		 * vhci_rx. */
+		spin_unlock_irqrestore(&the_controller->lock, flags);
+		return 0;
+	}
+
+	{
+		int ret = 0;
+		ret = usb_hcd_check_unlink_urb(hcd, urb, status);
+		if (ret) {
+			spin_unlock_irqrestore(&the_controller->lock, flags);
+			return 0;
+		}
+	}
+
+	 /* send unlink request here? */
+	vdev = priv->vdev;
+
+	if (!vdev->ud.tcp_socket) {
+		/* tcp connection is closed */
+		unsigned long flags2;
+
+		spin_lock_irqsave(&vdev->priv_lock, flags2);
+
+		uinfo("vhci_hcd: device %p seems to be disconnected\n", vdev);
+		list_del(&priv->list);
+		kfree(priv);
+		urb->hcpriv = NULL;
+
+		spin_unlock_irqrestore(&vdev->priv_lock, flags2);
+
+	} else {
+		/* tcp connection is alive */
+		unsigned long flags2;
+		struct vhci_unlink *unlink;
+
+		spin_lock_irqsave(&vdev->priv_lock, flags2);
+
+		/* setup CMD_UNLINK pdu */
+		unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
+		if (!unlink) {
+			uerr("malloc vhci_unlink\n");
+			spin_unlock_irqrestore(&vdev->priv_lock, flags2);
+			spin_unlock_irqrestore(&the_controller->lock, flags);
+			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
+			return -ENOMEM;
+		}
+
+		unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
+		if (unlink->seqnum == 0xffff)
+			uinfo("seqnum max\n");
+
+		unlink->unlink_seqnum = priv->seqnum;
+
+		uinfo("vhci_hcd: device %p seems to be still connected\n",
+									vdev);
+
+		/* send cmd_unlink and try to cancel the pending URB in the
+		 * peer */
+		list_add_tail(&unlink->list, &vdev->unlink_tx);
+		wake_up(&vdev->waitq_tx);
+
+		spin_unlock_irqrestore(&vdev->priv_lock, flags2);
+	}
+
+
+	/*
+	 * If tcp connection is alive, we have sent CMD_UNLINK.
+	 * vhci_rx will receive RET_UNLINK and give back the URB.
+	 * Otherwise, we give back it here.
+	 */
+	if (!vdev->ud.tcp_socket) {
+		/* tcp connection is closed */
+		uinfo("vhci_hcd: vhci_urb_dequeue() gives back urb %p\n", urb);
+
+		usb_hcd_unlink_urb_from_ep(hcd, urb);
+
+		spin_unlock_irqrestore(&the_controller->lock, flags);
+		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
+								urb->status);
+		spin_lock_irqsave(&the_controller->lock, flags);
+	}
+
+	spin_unlock_irqrestore(&the_controller->lock, flags);
+
+	dbg_vhci_hc("leave\n");
+	return 0;
+}
+
+
+static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
+{
+	struct vhci_unlink *unlink, *tmp;
+
+	spin_lock(&vdev->priv_lock);
+
+	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
+		list_del(&unlink->list);
+		kfree(unlink);
+	}
+
+	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
+		list_del(&unlink->list);
+		kfree(unlink);
+	}
+
+	spin_unlock(&vdev->priv_lock);
+}
+
+/*
+ * The important thing is that only one context begins cleanup.
+ * This is why error handling and cleanup become simple.
+ * We do not want to consider race condition as possible.
+ */
+static void vhci_shutdown_connection(struct usbip_device *ud)
+{
+	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
+
+	/* need this? see stub_dev.c */
+	if (ud->tcp_socket) {
+		udbg("shutdown tcp_socket %p\n", ud->tcp_socket);
+		kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
+	}
+
+	usbip_stop_threads(&vdev->ud);
+	uinfo("stop threads\n");
+
+	/* active connection is closed */
+	if (vdev->ud.tcp_socket != NULL) {
+		sock_release(vdev->ud.tcp_socket);
+		vdev->ud.tcp_socket = NULL;
+	}
+	uinfo("release socket\n");
+
+	vhci_device_unlink_cleanup(vdev);
+
+	/*
+	 * rh_port_disconnect() is a trigger of ...
+	 *   usb_disable_device():
+	 *	disable all the endpoints for a USB device.
+	 *   usb_disable_endpoint():
+	 *	disable endpoints. pending urbs are unlinked(dequeued).
+	 *
+	 * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
+	 * deteched device should release used urbs in a cleanup function(i.e.
+	 * xxx_disconnect()). Therefore, vhci_hcd does not need to release
+	 * pushed urbs and their private data in this function.
+	 *
+	 * NOTE: vhci_dequeue() must be considered carefully. When shutdowning
+	 * a connection, vhci_shutdown_connection() expects vhci_dequeue()
+	 * gives back pushed urbs and frees their private data by request of
+	 * the cleanup function of a USB driver. When unlinking a urb with an
+	 * active connection, vhci_dequeue() does not give back the urb which
+	 * is actually given back by vhci_rx after receiving its return pdu.
+	 *
+	 */
+	rh_port_disconnect(vdev->rhport);
+
+	uinfo("disconnect device\n");
+}
+
+
+static void vhci_device_reset(struct usbip_device *ud)
+{
+	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
+
+	spin_lock(&ud->lock);
+
+	vdev->speed  = 0;
+	vdev->devid  = 0;
+
+	ud->tcp_socket = NULL;
+
+	ud->status = VDEV_ST_NULL;
+
+	spin_unlock(&ud->lock);
+}
+
+static void vhci_device_unusable(struct usbip_device *ud)
+{
+	spin_lock(&ud->lock);
+
+	ud->status = VDEV_ST_ERROR;
+
+	spin_unlock(&ud->lock);
+}
+
+static void vhci_device_init(struct vhci_device *vdev)
+{
+	memset(vdev, 0, sizeof(*vdev));
+
+	usbip_task_init(&vdev->ud.tcp_rx, "vhci_rx", vhci_rx_loop);
+	usbip_task_init(&vdev->ud.tcp_tx, "vhci_tx", vhci_tx_loop);
+
+	vdev->ud.side   = USBIP_VHCI;
+	vdev->ud.status = VDEV_ST_NULL;
+	/* vdev->ud.lock   = SPIN_LOCK_UNLOCKED; */
+	spin_lock_init(&vdev->ud.lock);
+
+	INIT_LIST_HEAD(&vdev->priv_rx);
+	INIT_LIST_HEAD(&vdev->priv_tx);
+	INIT_LIST_HEAD(&vdev->unlink_tx);
+	INIT_LIST_HEAD(&vdev->unlink_rx);
+	/* vdev->priv_lock = SPIN_LOCK_UNLOCKED; */
+	spin_lock_init(&vdev->priv_lock);
+
+	init_waitqueue_head(&vdev->waitq_tx);
+
+	vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
+	vdev->ud.eh_ops.reset = vhci_device_reset;
+	vdev->ud.eh_ops.unusable = vhci_device_unusable;
+
+	usbip_start_eh(&vdev->ud);
+}
+
+
+/*----------------------------------------------------------------------*/
+
+static int vhci_start(struct usb_hcd *hcd)
+{
+	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
+	int rhport;
+	int err = 0;
+
+	dbg_vhci_hc("enter vhci_start\n");
+
+
+	/* initialize private data of usb_hcd */
+
+	for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
+		struct vhci_device *vdev = &vhci->vdev[rhport];
+		vhci_device_init(vdev);
+		vdev->rhport = rhport;
+	}
+
+	atomic_set(&vhci->seqnum, 0);
+	spin_lock_init(&vhci->lock);
+
+
+
+	hcd->power_budget = 0; /* no limit */
+	hcd->state  = HC_STATE_RUNNING;
+	hcd->uses_new_polling = 1;
+
+
+	/* vhci_hcd is now ready to be controlled through sysfs */
+	err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
+	if (err) {
+		uerr("create sysfs files\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static void vhci_stop(struct usb_hcd *hcd)
+{
+	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
+	int rhport = 0;
+
+	dbg_vhci_hc("stop VHCI controller\n");
+
+
+	/* 1. remove the userland interface of vhci_hcd */
+	sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
+
+	/* 2. shutdown all the ports of vhci_hcd */
+	for (rhport = 0 ; rhport < VHCI_NPORTS; rhport++) {
+		struct vhci_device *vdev = &vhci->vdev[rhport];
+
+		usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
+		usbip_stop_eh(&vdev->ud);
+	}
+
+
+	uinfo("vhci_stop done\n");
+}
+
+/*----------------------------------------------------------------------*/
+
+static int vhci_get_frame_number(struct usb_hcd *hcd)
+{
+	uerr("Not yet implemented\n");
+	return 0;
+}
+
+
+#ifdef CONFIG_PM
+
+/* FIXME: suspend/resume */
+static int vhci_bus_suspend(struct usb_hcd *hcd)
+{
+	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
+
+	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
+
+	spin_lock_irq(&vhci->lock);
+	/* vhci->rh_state = DUMMY_RH_SUSPENDED;
+	 * set_link_state(vhci); */
+	hcd->state = HC_STATE_SUSPENDED;
+	spin_unlock_irq(&vhci->lock);
+
+	return 0;
+}
+
+static int vhci_bus_resume(struct usb_hcd *hcd)
+{
+	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
+	int rc = 0;
+
+	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
+
+	spin_lock_irq(&vhci->lock);
+	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+		rc = -ESHUTDOWN;
+	} else {
+		/* vhci->rh_state = DUMMY_RH_RUNNING;
+		 * set_link_state(vhci);
+		 * if (!list_empty(&vhci->urbp_list))
+		 *	mod_timer(&vhci->timer, jiffies); */
+		hcd->state = HC_STATE_RUNNING;
+	}
+	spin_unlock_irq(&vhci->lock);
+	return rc;
+
+	return 0;
+}
+
+#else
+
+#define vhci_bus_suspend      NULL
+#define vhci_bus_resume       NULL
+#endif
+
+
+
+static struct hc_driver vhci_hc_driver = {
+	.description	= driver_name,
+	.product_desc	= driver_desc,
+	.hcd_priv_size	= sizeof(struct vhci_hcd),
+
+	.flags		= HCD_USB2,
+
+	.start		= vhci_start,
+	.stop 		= vhci_stop,
+
+	.urb_enqueue	= vhci_urb_enqueue,
+	.urb_dequeue	= vhci_urb_dequeue,
+
+	.get_frame_number = vhci_get_frame_number,
+
+	.hub_status_data = vhci_hub_status,
+	.hub_control    = vhci_hub_control,
+	.bus_suspend	= vhci_bus_suspend,
+	.bus_resume	= vhci_bus_resume,
+};
+
+static int vhci_hcd_probe(struct platform_device *pdev)
+{
+	struct usb_hcd		*hcd;
+	int			ret;
+
+	uinfo("proving...\n");
+
+	dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
+
+	/* will be removed */
+	if (pdev->dev.dma_mask) {
+		dev_info(&pdev->dev, "vhci_hcd DMA not supported\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Allocate and initialize hcd.
+	 * Our private data is also allocated automatically.
+	 */
+	hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, pdev->dev.bus_id);
+	if (!hcd) {
+		uerr("create hcd failed\n");
+		return -ENOMEM;
+	}
+
+
+	/* this is private data for vhci_hcd */
+	the_controller = hcd_to_vhci(hcd);
+
+	/*
+	 * Finish generic HCD structure initialization and register.
+	 * Call the driver's reset() and start() routines.
+	 */
+	ret = usb_add_hcd(hcd, 0, 0);
+	if (ret != 0) {
+		uerr("usb_add_hcd failed %d\n", ret);
+		usb_put_hcd(hcd);
+		the_controller = NULL;
+		return ret;
+	}
+
+
+	dbg_vhci_hc("bye\n");
+	return 0;
+}
+
+
+static int vhci_hcd_remove(struct platform_device *pdev)
+{
+	struct usb_hcd	*hcd;
+
+	hcd = platform_get_drvdata(pdev);
+	if (!hcd)
+		return 0;
+
+	/*
+	 * Disconnects the root hub,
+	 * then reverses the effects of usb_add_hcd(),
+	 * invoking the HCD's stop() methods.
+	 */
+	usb_remove_hcd(hcd);
+	usb_put_hcd(hcd);
+	the_controller = NULL;
+
+
+	return 0;
+}
+
+
+
+#ifdef CONFIG_PM
+
+/* what should happen for USB/IP under suspend/resume? */
+static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct usb_hcd *hcd;
+	int rhport = 0;
+	int connected = 0;
+	int ret = 0;
+
+	dev_dbg(&pdev->dev, "%s\n", __func__);
+
+	hcd = platform_get_drvdata(pdev);
+
+	spin_lock(&the_controller->lock);
+
+	for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
+		if (the_controller->port_status[rhport] &
+						USB_PORT_STAT_CONNECTION)
+			connected += 1;
+
+	spin_unlock(&the_controller->lock);
+
+	if (connected > 0) {
+		uinfo("We have %d active connection%s. Do not suspend.\n",
+				connected, (connected == 1 ? "" : "s"));
+		ret =  -EBUSY;
+	} else {
+		uinfo("suspend vhci_hcd");
+		clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+	}
+
+	return ret;
+}
+
+static int vhci_hcd_resume(struct platform_device *pdev)
+{
+	struct usb_hcd *hcd;
+
+	dev_dbg(&pdev->dev, "%s\n", __func__);
+
+	hcd = platform_get_drvdata(pdev);
+	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+	usb_hcd_poll_rh_status(hcd);
+
+	return 0;
+}
+
+#else
+
+#define vhci_hcd_suspend	NULL
+#define vhci_hcd_resume		NULL
+
+#endif
+
+
+static struct platform_driver vhci_driver = {
+	.probe	= vhci_hcd_probe,
+	.remove	= __devexit_p(vhci_hcd_remove),
+	.suspend = vhci_hcd_suspend,
+	.resume	= vhci_hcd_resume,
+	.driver	= {
+		.name = (char *) driver_name,
+		.owner = THIS_MODULE,
+	},
+};
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
+ * We need to add this virtual device as a platform device arbitrarily:
+ *	1. platform_device_register()
+ */
+static void the_pdev_release(struct device *dev)
+{
+	return;
+}
+
+static struct platform_device the_pdev = {
+	/* should be the same name as driver_name */
+	.name = (char *) driver_name,
+	.id = -1,
+	.dev = {
+		/* .driver = &vhci_driver, */
+		.release = the_pdev_release,
+	},
+};
+
+static int __init vhci_init(void)
+{
+	int ret;
+
+	dbg_vhci_hc("enter\n");
+	if (usb_disabled())
+		return -ENODEV;
+
+	printk(KERN_INFO KBUILD_MODNAME ": %s, %s\n", driver_name,
+	       DRIVER_VERSION);
+
+	ret = platform_driver_register(&vhci_driver);
+	if (ret < 0)
+		goto err_driver_register;
+
+	ret = platform_device_register(&the_pdev);
+	if (ret < 0)
+		goto err_platform_device_register;
+
+	dbg_vhci_hc("bye\n");
+	return ret;
+
+	/* error occurred */
+err_platform_device_register:
+	platform_driver_unregister(&vhci_driver);
+
+err_driver_register:
+	dbg_vhci_hc("bye\n");
+	return ret;
+}
+module_init(vhci_init);
+
+static void __exit vhci_cleanup(void)
+{
+	dbg_vhci_hc("enter\n");
+
+	platform_device_unregister(&the_pdev);
+	platform_driver_unregister(&vhci_driver);
+
+	dbg_vhci_hc("bye\n");
+}
+module_exit(vhci_cleanup);
diff --git a/drivers/staging/usbip/vhci_rx.c b/drivers/staging/usbip/vhci_rx.c
new file mode 100644
index 000000000000..933ccaf50afb
--- /dev/null
+++ b/drivers/staging/usbip/vhci_rx.c
@@ -0,0 +1,251 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#include "usbip_common.h"
+#include "vhci.h"
+
+
+/* get URB from transmitted urb queue */
+static struct urb *pickup_urb_and_free_priv(struct vhci_device *vdev,
+					    __u32 seqnum)
+{
+	struct vhci_priv *priv, *tmp;
+	struct urb *urb = NULL;
+	int status;
+
+	spin_lock(&vdev->priv_lock);
+
+	list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {
+		if (priv->seqnum == seqnum) {
+			urb = priv->urb;
+			status = urb->status;
+
+			dbg_vhci_rx("find urb %p vurb %p seqnum %u\n",
+				    urb, priv, seqnum);
+
+			/* TODO: fix logic here to improve indent situtation */
+			if (status != -EINPROGRESS) {
+				if (status == -ENOENT ||
+				     status == -ECONNRESET)
+					dev_info(&urb->dev->dev,
+						 "urb %p was unlinked "
+						 "%ssynchronuously.\n", urb,
+						 status == -ENOENT ? "" : "a");
+				else
+					dev_info(&urb->dev->dev,
+						 "urb %p may be in a error, "
+						 "status %d\n", urb, status);
+			}
+
+			list_del(&priv->list);
+			kfree(priv);
+			urb->hcpriv = NULL;
+
+			break;
+		}
+	}
+
+	spin_unlock(&vdev->priv_lock);
+
+	return urb;
+}
+
+static void vhci_recv_ret_submit(struct vhci_device *vdev,
+						struct usbip_header *pdu)
+{
+	struct usbip_device *ud = &vdev->ud;
+	struct urb *urb;
+
+
+	urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
+
+
+	if (!urb) {
+		uerr("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
+		uinfo("max seqnum %d\n", atomic_read(&the_controller->seqnum));
+		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
+		return;
+	}
+
+
+	/* unpack the pdu to a urb */
+	usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
+
+
+	/* recv transfer buffer */
+	if (usbip_recv_xbuff(ud, urb) < 0)
+		return;
+
+
+	/* recv iso_packet_descriptor */
+	if (usbip_recv_iso(ud, urb) < 0)
+		return;
+
+
+	if (dbg_flag_vhci_rx)
+		usbip_dump_urb(urb);
+
+
+	dbg_vhci_rx("now giveback urb %p\n", urb);
+
+	spin_lock(&the_controller->lock);
+	usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
+	spin_unlock(&the_controller->lock);
+
+	usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
+
+
+	dbg_vhci_rx("Leave\n");
+
+	return;
+}
+
+
+static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
+		struct usbip_header *pdu)
+{
+	struct vhci_unlink *unlink, *tmp;
+
+	spin_lock(&vdev->priv_lock);
+
+	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
+		uinfo("unlink->seqnum %lu\n", unlink->seqnum);
+		if (unlink->seqnum == pdu->base.seqnum) {
+			dbg_vhci_rx("found pending unlink, %lu\n",
+							unlink->seqnum);
+			list_del(&unlink->list);
+
+			spin_unlock(&vdev->priv_lock);
+			return unlink;
+		}
+	}
+
+	spin_unlock(&vdev->priv_lock);
+
+	return NULL;
+}
+
+
+static void vhci_recv_ret_unlink(struct vhci_device *vdev,
+						struct usbip_header *pdu)
+{
+	struct vhci_unlink *unlink;
+	struct urb *urb;
+
+	usbip_dump_header(pdu);
+
+	unlink = dequeue_pending_unlink(vdev, pdu);
+	if (!unlink) {
+		uinfo("cannot find the pending unlink %u\n", pdu->base.seqnum);
+		return;
+	}
+
+	urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
+	if (!urb) {
+		/*
+		 * I get the result of a unlink request. But, it seems that I
+		 * already received the result of its submit result and gave
+		 * back the URB.
+		 */
+		uinfo("the urb (seqnum %d) was already given backed\n",
+							pdu->base.seqnum);
+	} else {
+		dbg_vhci_rx("now giveback urb %p\n", urb);
+
+		/* If unlink is succeed, status is -ECONNRESET */
+		urb->status = pdu->u.ret_unlink.status;
+		uinfo("%d\n", urb->status);
+
+		spin_lock(&the_controller->lock);
+		usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
+		spin_unlock(&the_controller->lock);
+
+		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
+								urb->status);
+	}
+
+	kfree(unlink);
+
+	return;
+}
+
+/* recv a pdu */
+static void vhci_rx_pdu(struct usbip_device *ud)
+{
+	int ret;
+	struct usbip_header pdu;
+	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
+
+
+	dbg_vhci_rx("Enter\n");
+
+	memset(&pdu, 0, sizeof(pdu));
+
+
+	/* 1. receive a pdu header */
+	ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
+	if (ret != sizeof(pdu)) {
+		uerr("receiving pdu failed! size is %d, should be %d\n",
+				ret, sizeof(pdu));
+		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
+		return;
+	}
+
+	usbip_header_correct_endian(&pdu, 0);
+
+	if (dbg_flag_vhci_rx)
+		usbip_dump_header(&pdu);
+
+	switch (pdu.base.command) {
+	case USBIP_RET_SUBMIT:
+		vhci_recv_ret_submit(vdev, &pdu);
+		break;
+	case USBIP_RET_UNLINK:
+		vhci_recv_ret_unlink(vdev, &pdu);
+		break;
+	default:
+		/* NOTREACHED */
+		uerr("unknown pdu %u\n", pdu.base.command);
+		usbip_dump_header(&pdu);
+		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
+	}
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+void vhci_rx_loop(struct usbip_task *ut)
+{
+	struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);
+
+
+	while (1) {
+		if (signal_pending(current)) {
+			dbg_vhci_rx("signal catched!\n");
+			break;
+		}
+
+
+		if (usbip_event_happend(ud))
+			break;
+
+		vhci_rx_pdu(ud);
+	}
+}
+
diff --git a/drivers/staging/usbip/vhci_sysfs.c b/drivers/staging/usbip/vhci_sysfs.c
new file mode 100644
index 000000000000..24c2851a8f84
--- /dev/null
+++ b/drivers/staging/usbip/vhci_sysfs.c
@@ -0,0 +1,250 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#include "usbip_common.h"
+#include "vhci.h"
+
+#include <linux/in.h>
+
+/* TODO: refine locking ?*/
+
+/* Sysfs entry to show port status */
+static ssize_t show_status(struct device *dev, struct device_attribute *attr,
+			   char *out)
+{
+	char *s = out;
+	int i = 0;
+
+	if (!the_controller || !out)
+		BUG();
+
+	spin_lock(&the_controller->lock);
+
+	/*
+	 * output example:
+	 * prt sta spd dev socket           local_busid
+	 * 000 004 000 000         c5a7bb80 1-2.3
+	 * 001 004 000 000         d8cee980 2-3.4
+	 *
+	 * IP address can be retrieved from a socket pointer address by looking
+	 * up /proc/net/{tcp,tcp6}. Also, a userland program may remember a
+	 * port number and its peer IP address.
+	 */
+	out += sprintf(out, "prt sta spd bus dev socket           "
+		       "local_busid\n");
+
+	for (i = 0; i < VHCI_NPORTS; i++) {
+		struct vhci_device *vdev = port_to_vdev(i);
+
+		spin_lock(&vdev->ud.lock);
+
+		out += sprintf(out, "%03u %03u ", i, vdev->ud.status);
+
+		if (vdev->ud.status == VDEV_ST_USED) {
+			out += sprintf(out, "%03u %08x ",
+					vdev->speed, vdev->devid);
+			out += sprintf(out, "%16p ", vdev->ud.tcp_socket);
+			out += sprintf(out, "%s", vdev->udev->dev.bus_id);
+
+		} else
+			out += sprintf(out, "000 000 000 0000000000000000 0-0");
+
+		out += sprintf(out, "\n");
+
+		spin_unlock(&vdev->ud.lock);
+	}
+
+	spin_unlock(&the_controller->lock);
+
+	return out - s;
+}
+static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
+
+/* Sysfs entry to shutdown a virtual connection */
+static int vhci_port_disconnect(__u32 rhport)
+{
+	struct vhci_device *vdev;
+
+	dbg_vhci_sysfs("enter\n");
+
+	/* lock */
+	spin_lock(&the_controller->lock);
+
+	vdev = port_to_vdev(rhport);
+
+	spin_lock(&vdev->ud.lock);
+	if (vdev->ud.status == VDEV_ST_NULL) {
+		uerr("not connected %d\n", vdev->ud.status);
+
+		/* unlock */
+		spin_unlock(&vdev->ud.lock);
+		spin_unlock(&the_controller->lock);
+
+		return -EINVAL;
+	}
+
+	/* unlock */
+	spin_unlock(&vdev->ud.lock);
+	spin_unlock(&the_controller->lock);
+
+	usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);
+
+	return 0;
+}
+
+static ssize_t store_detach(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	int err;
+	__u32 rhport = 0;
+
+	sscanf(buf, "%u", &rhport);
+
+	/* check rhport */
+	if (rhport >= VHCI_NPORTS) {
+		uerr("invalid port %u\n", rhport);
+		return -EINVAL;
+	}
+
+	err = vhci_port_disconnect(rhport);
+	if (err < 0)
+		return -EINVAL;
+
+	dbg_vhci_sysfs("Leave\n");
+	return count;
+}
+static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);
+
+/* Sysfs entry to establish a virtual connection */
+static int valid_args(__u32 rhport, enum usb_device_speed speed)
+{
+	/* check rhport */
+	if ((rhport < 0) || (rhport >= VHCI_NPORTS)) {
+		uerr("port %u\n", rhport);
+		return -EINVAL;
+	}
+
+	/* check speed */
+	switch (speed) {
+	case USB_SPEED_LOW:
+	case USB_SPEED_FULL:
+	case USB_SPEED_HIGH:
+	case USB_SPEED_VARIABLE:
+		break;
+	default:
+		uerr("speed %d\n", speed);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * To start a new USB/IP attachment, a userland program needs to setup a TCP
+ * connection and then write its socket descriptor with remote device
+ * information into this sysfs file.
+ *
+ * A remote device is virtually attached to the root-hub port of @rhport with
+ * @speed. @devid is embedded into a request to specify the remote device in a
+ * server host.
+ *
+ * write() returns 0 on success, else negative errno.
+ */
+static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct vhci_device *vdev;
+	struct socket *socket;
+	int sockfd = 0;
+	__u32 rhport = 0, devid = 0, speed = 0;
+
+	/*
+	 * @rhport: port number of vhci_hcd
+	 * @sockfd: socket descriptor of an established TCP connection
+	 * @devid: unique device identifier in a remote host
+	 * @speed: usb device speed in a remote host
+	 */
+	sscanf(buf, "%u %u %u %u", &rhport, &sockfd, &devid, &speed);
+
+	dbg_vhci_sysfs("rhport(%u) sockfd(%u) devid(%u) speed(%u)\n",
+			rhport, sockfd, devid, speed);
+
+
+	/* check received parameters */
+	if (valid_args(rhport, speed) < 0)
+		return -EINVAL;
+
+	/* check sockfd */
+	socket = sockfd_to_socket(sockfd);
+	if (!socket)
+		return  -EINVAL;
+
+	/* now need lock until setting vdev status as used */
+
+	/* begin a lock */
+	spin_lock(&the_controller->lock);
+
+	vdev = port_to_vdev(rhport);
+
+	spin_lock(&vdev->ud.lock);
+
+	if (vdev->ud.status != VDEV_ST_NULL) {
+		/* end of the lock */
+		spin_unlock(&vdev->ud.lock);
+		spin_unlock(&the_controller->lock);
+
+		uerr("port %d already used\n", rhport);
+		return -EINVAL;
+	}
+
+	uinfo("rhport(%u) sockfd(%d) devid(%u) speed(%u)\n",
+			rhport, sockfd, devid, speed);
+
+	vdev->devid         = devid;
+	vdev->speed         = speed;
+	vdev->ud.tcp_socket = socket;
+	vdev->ud.status     = VDEV_ST_NOTASSIGNED;
+
+	spin_unlock(&vdev->ud.lock);
+	spin_unlock(&the_controller->lock);
+	/* end the lock */
+
+	/*
+	 * this function will sleep, so should be out of the lock. but, it's ok
+	 * because we already marked vdev as being used. really?
+	 */
+	usbip_start_threads(&vdev->ud);
+
+	rh_port_connect(rhport, speed);
+
+	return count;
+}
+static DEVICE_ATTR(attach, S_IWUSR, NULL, store_attach);
+
+static struct attribute *dev_attrs[] = {
+	&dev_attr_status.attr,
+	&dev_attr_detach.attr,
+	&dev_attr_attach.attr,
+	&dev_attr_usbip_debug.attr,
+	NULL,
+};
+
+struct attribute_group dev_attr_group = {
+	.attrs = dev_attrs,
+};
diff --git a/drivers/staging/usbip/vhci_tx.c b/drivers/staging/usbip/vhci_tx.c
new file mode 100644
index 000000000000..1f552a95f486
--- /dev/null
+++ b/drivers/staging/usbip/vhci_tx.c
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#include "usbip_common.h"
+#include "vhci.h"
+
+
+static void setup_cmd_submit_pdu(struct usbip_header *pdup,  struct urb *urb)
+{
+	struct vhci_priv *priv = ((struct vhci_priv *)urb->hcpriv);
+	struct vhci_device *vdev = priv->vdev;
+
+	dbg_vhci_tx("URB, local devnum %u, remote devid %u\n",
+				usb_pipedevice(urb->pipe), vdev->devid);
+
+	pdup->base.command = USBIP_CMD_SUBMIT;
+	pdup->base.seqnum  = priv->seqnum;
+	pdup->base.devid   = vdev->devid;
+	if (usb_pipein(urb->pipe))
+		pdup->base.direction = USBIP_DIR_IN;
+	else
+		pdup->base.direction = USBIP_DIR_OUT;
+	pdup->base.ep      = usb_pipeendpoint(urb->pipe);
+
+	usbip_pack_pdu(pdup, urb, USBIP_CMD_SUBMIT, 1);
+
+	if (urb->setup_packet)
+		memcpy(pdup->u.cmd_submit.setup, urb->setup_packet, 8);
+}
+
+static struct vhci_priv *dequeue_from_priv_tx(struct vhci_device *vdev)
+{
+	unsigned long flags;
+	struct vhci_priv *priv, *tmp;
+
+	spin_lock_irqsave(&vdev->priv_lock, flags);
+
+	list_for_each_entry_safe(priv, tmp, &vdev->priv_tx, list) {
+		list_move_tail(&priv->list, &vdev->priv_rx);
+		spin_unlock_irqrestore(&vdev->priv_lock, flags);
+		return priv;
+	}
+
+	spin_unlock_irqrestore(&vdev->priv_lock, flags);
+
+	return NULL;
+}
+
+
+
+static int vhci_send_cmd_submit(struct vhci_device *vdev)
+{
+	struct vhci_priv *priv = NULL;
+
+	struct msghdr msg;
+	struct kvec iov[3];
+	size_t txsize;
+
+	size_t total_size = 0;
+
+	while ((priv = dequeue_from_priv_tx(vdev)) != NULL) {
+		int ret;
+		struct urb *urb = priv->urb;
+		struct usbip_header pdu_header;
+		void *iso_buffer = NULL;
+
+		txsize = 0;
+		memset(&pdu_header, 0, sizeof(pdu_header));
+		memset(&msg, 0, sizeof(msg));
+		memset(&iov, 0, sizeof(iov));
+
+		dbg_vhci_tx("setup txdata urb %p\n", urb);
+
+
+		/* 1. setup usbip_header */
+		setup_cmd_submit_pdu(&pdu_header, urb);
+		usbip_header_correct_endian(&pdu_header, 1);
+
+		iov[0].iov_base = &pdu_header;
+		iov[0].iov_len  = sizeof(pdu_header);
+		txsize += sizeof(pdu_header);
+
+		/* 2. setup transfer buffer */
+		if (!usb_pipein(urb->pipe) && urb->transfer_buffer_length > 0) {
+			iov[1].iov_base = urb->transfer_buffer;
+			iov[1].iov_len  = urb->transfer_buffer_length;
+			txsize += urb->transfer_buffer_length;
+		}
+
+		/* 3. setup iso_packet_descriptor */
+		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
+			ssize_t len = 0;
+
+			iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
+			if (!iso_buffer) {
+				usbip_event_add(&vdev->ud,
+						SDEV_EVENT_ERROR_MALLOC);
+				return -1;
+			}
+
+			iov[2].iov_base = iso_buffer;
+			iov[2].iov_len  = len;
+			txsize += len;
+		}
+
+		ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 3, txsize);
+		if (ret != txsize) {
+			uerr("sendmsg failed!, retval %d for %zd\n", ret,
+								txsize);
+			kfree(iso_buffer);
+			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
+			return -1;
+		}
+
+		kfree(iso_buffer);
+		dbg_vhci_tx("send txdata\n");
+
+		total_size += txsize;
+	}
+
+	return total_size;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+static struct vhci_unlink *dequeue_from_unlink_tx(struct vhci_device *vdev)
+{
+	unsigned long flags;
+	struct vhci_unlink *unlink, *tmp;
+
+	spin_lock_irqsave(&vdev->priv_lock, flags);
+
+	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
+		list_move_tail(&unlink->list, &vdev->unlink_rx);
+		spin_unlock_irqrestore(&vdev->priv_lock, flags);
+		return unlink;
+	}
+
+	spin_unlock_irqrestore(&vdev->priv_lock, flags);
+
+	return NULL;
+}
+
+static int vhci_send_cmd_unlink(struct vhci_device *vdev)
+{
+	struct vhci_unlink *unlink = NULL;
+
+	struct msghdr msg;
+	struct kvec iov[3];
+	size_t txsize;
+
+	size_t total_size = 0;
+
+	while ((unlink = dequeue_from_unlink_tx(vdev)) != NULL) {
+		int ret;
+		struct usbip_header pdu_header;
+
+		txsize = 0;
+		memset(&pdu_header, 0, sizeof(pdu_header));
+		memset(&msg, 0, sizeof(msg));
+		memset(&iov, 0, sizeof(iov));
+
+		dbg_vhci_tx("setup cmd unlink, %lu \n", unlink->seqnum);
+
+
+		/* 1. setup usbip_header */
+		pdu_header.base.command = USBIP_CMD_UNLINK;
+		pdu_header.base.seqnum  = unlink->seqnum;
+		pdu_header.base.devid	= vdev->devid;
+		pdu_header.base.ep	= 0;
+		pdu_header.u.cmd_unlink.seqnum = unlink->unlink_seqnum;
+
+		usbip_header_correct_endian(&pdu_header, 1);
+
+		iov[0].iov_base = &pdu_header;
+		iov[0].iov_len  = sizeof(pdu_header);
+		txsize += sizeof(pdu_header);
+
+		ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 1, txsize);
+		if (ret != txsize) {
+			uerr("sendmsg failed!, retval %d for %zd\n", ret,
+								txsize);
+			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
+			return -1;
+		}
+
+
+		dbg_vhci_tx("send txdata\n");
+
+		total_size += txsize;
+	}
+
+	return total_size;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+void vhci_tx_loop(struct usbip_task *ut)
+{
+	struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
+	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
+
+	while (1) {
+		if (signal_pending(current)) {
+			uinfo("vhci_tx signal catched\n");
+			break;
+		}
+
+		if (vhci_send_cmd_submit(vdev) < 0)
+			break;
+
+		if (vhci_send_cmd_unlink(vdev) < 0)
+			break;
+
+		wait_event_interruptible(vdev->waitq_tx,
+				(!list_empty(&vdev->priv_tx) ||
+				 !list_empty(&vdev->unlink_tx)));
+
+		dbg_vhci_tx("pending urbs ?, now wake up\n");
+	}
+}