/*
 * USB hub driver.
 *
 * (C) Copyright 1999 Linus Torvalds
 * (C) Copyright 1999 Johannes Erdfelt
 * (C) Copyright 1999 Gregory P. Smith
 * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/completion.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/ioctl.h>
#include <linux/usb.h>
#include <linux/usbdevice_fs.h>
#include <linux/usb/hcd.h>
#include <linux/usb/quirks.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <linux/freezer.h>

#include <asm/uaccess.h>
#include <asm/byteorder.h>

#include "usb.h"

/* if we are in debug mode, always announce new devices */
#ifdef DEBUG
#ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES
#define CONFIG_USB_ANNOUNCE_NEW_DEVICES
#endif
#endif

struct usb_hub {
	struct device		*intfdev;	/* the "interface" device */
	struct usb_device	*hdev;
	struct kref		kref;
	struct urb		*urb;		/* for interrupt polling pipe */

	/* buffer for urb ... with extra space in case of babble */
	char			(*buffer)[8];
	union {
		struct usb_hub_status	hub;
		struct usb_port_status	port;
	}			*status;	/* buffer for status reports */
	struct mutex		status_mutex;	/* for the status buffer */

	int			error;		/* last reported error */
	int			nerrors;	/* track consecutive errors */

	struct list_head	event_list;	/* hubs w/data or errs ready */
	unsigned long		event_bits[1];	/* status change bitmask */
	unsigned long		change_bits[1];	/* ports with logical connect
							status change */
	unsigned long		busy_bits[1];	/* ports being reset or
							resumed */
	unsigned long		removed_bits[1]; /* ports with a "removed"
							device present */
#if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */
#error event_bits[] is too short!
#endif

	struct usb_hub_descriptor *descriptor;	/* class descriptor */
	struct usb_tt		tt;		/* Transaction Translator */

	unsigned		mA_per_port;	/* current for each child */

	unsigned		limited_power:1;
	unsigned		quiescing:1;
	unsigned		disconnected:1;

	unsigned		has_indicators:1;
	u8			indicator[USB_MAXCHILDREN];
	struct delayed_work	leds;
	struct delayed_work	init_work;
	void			**port_owners;
};

static inline int hub_is_superspeed(struct usb_device *hdev)
{
	return (hdev->descriptor.bDeviceProtocol == 3);
}

/* Protect struct usb_device->state and ->children members
 * Note: Both are also protected by ->dev.sem, except that ->state can
 * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
static DEFINE_SPINLOCK(device_state_lock);

/* khubd's worklist and its lock */
static DEFINE_SPINLOCK(hub_event_lock);
static LIST_HEAD(hub_event_list);	/* List of hubs needing servicing */

/* Wakes up khubd */
static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);

static struct task_struct *khubd_task;

/* cycle leds on hubs that aren't blinking for attention */
static int blinkenlights = 0;
module_param (blinkenlights, bool, S_IRUGO);
MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");

/*
 * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
 * 10 seconds to send reply for the initial 64-byte descriptor request.
 */
/* define initial 64-byte descriptor request timeout in milliseconds */
static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(initial_descriptor_timeout,
		"initial 64-byte descriptor request timeout in milliseconds "
		"(default 5000 - 5.0 seconds)");

/*
 * As of 2.6.10 we introduce a new USB device initialization scheme which
 * closely resembles the way Windows works.  Hopefully it will be compatible
 * with a wider range of devices than the old scheme.  However some previously
 * working devices may start giving rise to "device not accepting address"
 * errors; if that happens the user can try the old scheme by adjusting the
 * following module parameters.
 *
 * For maximum flexibility there are two boolean parameters to control the
 * hub driver's behavior.  On the first initialization attempt, if the
 * "old_scheme_first" parameter is set then the old scheme will be used,
 * otherwise the new scheme is used.  If that fails and "use_both_schemes"
 * is set, then the driver will make another attempt, using the other scheme.
 */
static int old_scheme_first = 0;
module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(old_scheme_first,
		 "start with the old device initialization scheme");

static int use_both_schemes = 1;
module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(use_both_schemes,
		"try the other device initialization scheme if the "
		"first one fails");

/* Mutual exclusion for EHCI CF initialization.  This interferes with
 * port reset on some companion controllers.
 */
DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);

#define HUB_DEBOUNCE_TIMEOUT	1500
#define HUB_DEBOUNCE_STEP	  25
#define HUB_DEBOUNCE_STABLE	 100


static int usb_reset_and_verify_device(struct usb_device *udev);

static inline char *portspeed(struct usb_hub *hub, int portstatus)
{
	if (hub_is_superspeed(hub->hdev))
		return "5.0 Gb/s";
	if (portstatus & USB_PORT_STAT_HIGH_SPEED)
    		return "480 Mb/s";
	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
		return "1.5 Mb/s";
	else
		return "12 Mb/s";
}

/* Note that hdev or one of its children must be locked! */
static struct usb_hub *hdev_to_hub(struct usb_device *hdev)
{
	if (!hdev || !hdev->actconfig)
		return NULL;
	return usb_get_intfdata(hdev->actconfig->interface[0]);
}

/* USB 2.0 spec Section 11.24.4.5 */
static int get_hub_descriptor(struct usb_device *hdev, void *data)
{
	int i, ret, size;
	unsigned dtype;

	if (hub_is_superspeed(hdev)) {
		dtype = USB_DT_SS_HUB;
		size = USB_DT_SS_HUB_SIZE;
	} else {
		dtype = USB_DT_HUB;
		size = sizeof(struct usb_hub_descriptor);
	}

	for (i = 0; i < 3; i++) {
		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
			dtype << 8, 0, data, size,
			USB_CTRL_GET_TIMEOUT);
		if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
			return ret;
	}
	return -EINVAL;
}

/*
 * USB 2.0 spec Section 11.24.2.1
 */
static int clear_hub_feature(struct usb_device *hdev, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
}

/*
 * USB 2.0 spec Section 11.24.2.2
 */
static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
		NULL, 0, 1000);
}

/*
 * USB 2.0 spec Section 11.24.2.13
 */
static int set_port_feature(struct usb_device *hdev, int port1, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
		NULL, 0, 1000);
}

/*
 * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
 * for info about using port indicators
 */
static void set_port_led(
	struct usb_hub *hub,
	int port1,
	int selector
)
{
	int status = set_port_feature(hub->hdev, (selector << 8) | port1,
			USB_PORT_FEAT_INDICATOR);
	if (status < 0)
		dev_dbg (hub->intfdev,
			"port %d indicator %s status %d\n",
			port1,
			({ char *s; switch (selector) {
			case HUB_LED_AMBER: s = "amber"; break;
			case HUB_LED_GREEN: s = "green"; break;
			case HUB_LED_OFF: s = "off"; break;
			case HUB_LED_AUTO: s = "auto"; break;
			default: s = "??"; break;
			}; s; }),
			status);
}

#define	LED_CYCLE_PERIOD	((2*HZ)/3)

static void led_work (struct work_struct *work)
{
	struct usb_hub		*hub =
		container_of(work, struct usb_hub, leds.work);
	struct usb_device	*hdev = hub->hdev;
	unsigned		i;
	unsigned		changed = 0;
	int			cursor = -1;

	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
		return;

	for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
		unsigned	selector, mode;

		/* 30%-50% duty cycle */

		switch (hub->indicator[i]) {
		/* cycle marker */
		case INDICATOR_CYCLE:
			cursor = i;
			selector = HUB_LED_AUTO;
			mode = INDICATOR_AUTO;
			break;
		/* blinking green = sw attention */
		case INDICATOR_GREEN_BLINK:
			selector = HUB_LED_GREEN;
			mode = INDICATOR_GREEN_BLINK_OFF;
			break;
		case INDICATOR_GREEN_BLINK_OFF:
			selector = HUB_LED_OFF;
			mode = INDICATOR_GREEN_BLINK;
			break;
		/* blinking amber = hw attention */
		case INDICATOR_AMBER_BLINK:
			selector = HUB_LED_AMBER;
			mode = INDICATOR_AMBER_BLINK_OFF;
			break;
		case INDICATOR_AMBER_BLINK_OFF:
			selector = HUB_LED_OFF;
			mode = INDICATOR_AMBER_BLINK;
			break;
		/* blink green/amber = reserved */
		case INDICATOR_ALT_BLINK:
			selector = HUB_LED_GREEN;
			mode = INDICATOR_ALT_BLINK_OFF;
			break;
		case INDICATOR_ALT_BLINK_OFF:
			selector = HUB_LED_AMBER;
			mode = INDICATOR_ALT_BLINK;
			break;
		default:
			continue;
		}
		if (selector != HUB_LED_AUTO)
			changed = 1;
		set_port_led(hub, i + 1, selector);
		hub->indicator[i] = mode;
	}
	if (!changed && blinkenlights) {
		cursor++;
		cursor %= hub->descriptor->bNbrPorts;
		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
		hub->indicator[cursor] = INDICATOR_CYCLE;
		changed++;
	}
	if (changed)
		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
}

/* use a short timeout for hub/port status fetches */
#define	USB_STS_TIMEOUT		1000
#define	USB_STS_RETRIES		5

/*
 * USB 2.0 spec Section 11.24.2.6
 */
static int get_hub_status(struct usb_device *hdev,
		struct usb_hub_status *data)
{
	int i, status = -ETIMEDOUT;

	for (i = 0; i < USB_STS_RETRIES &&
			(status == -ETIMEDOUT || status == -EPIPE); i++) {
		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
			data, sizeof(*data), USB_STS_TIMEOUT);
	}
	return status;
}

/*
 * USB 2.0 spec Section 11.24.2.7
 */
static int get_port_status(struct usb_device *hdev, int port1,
		struct usb_port_status *data)
{
	int i, status = -ETIMEDOUT;

	for (i = 0; i < USB_STS_RETRIES &&
			(status == -ETIMEDOUT || status == -EPIPE); i++) {
		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
			data, sizeof(*data), USB_STS_TIMEOUT);
	}
	return status;
}

static int hub_port_status(struct usb_hub *hub, int port1,
		u16 *status, u16 *change)
{
	int ret;

	mutex_lock(&hub->status_mutex);
	ret = get_port_status(hub->hdev, port1, &hub->status->port);
	if (ret < 4) {
		dev_err(hub->intfdev,
			"%s failed (err = %d)\n", __func__, ret);
		if (ret >= 0)
			ret = -EIO;
	} else {
		*status = le16_to_cpu(hub->status->port.wPortStatus);
		*change = le16_to_cpu(hub->status->port.wPortChange);

		ret = 0;
	}
	mutex_unlock(&hub->status_mutex);
	return ret;
}

static void kick_khubd(struct usb_hub *hub)
{
	unsigned long	flags;

	spin_lock_irqsave(&hub_event_lock, flags);
	if (!hub->disconnected && list_empty(&hub->event_list)) {
		list_add_tail(&hub->event_list, &hub_event_list);

		/* Suppress autosuspend until khubd runs */
		usb_autopm_get_interface_no_resume(
				to_usb_interface(hub->intfdev));
		wake_up(&khubd_wait);
	}
	spin_unlock_irqrestore(&hub_event_lock, flags);
}

void usb_kick_khubd(struct usb_device *hdev)
{
	struct usb_hub *hub = hdev_to_hub(hdev);

	if (hub)
		kick_khubd(hub);
}


/* completion function, fires on port status changes and various faults */
static void hub_irq(struct urb *urb)
{
	struct usb_hub *hub = urb->context;
	int status = urb->status;
	unsigned i;
	unsigned long bits;

	switch (status) {
	case -ENOENT:		/* synchronous unlink */
	case -ECONNRESET:	/* async unlink */
	case -ESHUTDOWN:	/* hardware going away */
		return;

	default:		/* presumably an error */
		/* Cause a hub reset after 10 consecutive errors */
		dev_dbg (hub->intfdev, "transfer --> %d\n", status);
		if ((++hub->nerrors < 10) || hub->error)
			goto resubmit;
		hub->error = status;
		/* FALL THROUGH */

	/* let khubd handle things */
	case 0:			/* we got data:  port status changed */
		bits = 0;
		for (i = 0; i < urb->actual_length; ++i)
			bits |= ((unsigned long) ((*hub->buffer)[i]))
					<< (i*8);
		hub->event_bits[0] = bits;
		break;
	}

	hub->nerrors = 0;

	/* Something happened, let khubd figure it out */
	kick_khubd(hub);

resubmit:
	if (hub->quiescing)
		return;

	if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
			&& status != -ENODEV && status != -EPERM)
		dev_err (hub->intfdev, "resubmit --> %d\n", status);
}

/* USB 2.0 spec Section 11.24.2.3 */
static inline int
hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
			       tt, NULL, 0, 1000);
}

/*
 * enumeration blocks khubd for a long time. we use keventd instead, since
 * long blocking there is the exception, not the rule.  accordingly, HCDs
 * talking to TTs must queue control transfers (not just bulk and iso), so
 * both can talk to the same hub concurrently.
 */
static void hub_tt_work(struct work_struct *work)
{
	struct usb_hub		*hub =
		container_of(work, struct usb_hub, tt.clear_work);
	unsigned long		flags;
	int			limit = 100;

	spin_lock_irqsave (&hub->tt.lock, flags);
	while (--limit && !list_empty (&hub->tt.clear_list)) {
		struct list_head	*next;
		struct usb_tt_clear	*clear;
		struct usb_device	*hdev = hub->hdev;
		const struct hc_driver	*drv;
		int			status;

		next = hub->tt.clear_list.next;
		clear = list_entry (next, struct usb_tt_clear, clear_list);
		list_del (&clear->clear_list);

		/* drop lock so HCD can concurrently report other TT errors */
		spin_unlock_irqrestore (&hub->tt.lock, flags);
		status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
		if (status)
			dev_err (&hdev->dev,
				"clear tt %d (%04x) error %d\n",
				clear->tt, clear->devinfo, status);

		/* Tell the HCD, even if the operation failed */
		drv = clear->hcd->driver;
		if (drv->clear_tt_buffer_complete)
			(drv->clear_tt_buffer_complete)(clear->hcd, clear->ep);

		kfree(clear);
		spin_lock_irqsave(&hub->tt.lock, flags);
	}
	spin_unlock_irqrestore (&hub->tt.lock, flags);
}

/**
 * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub
 * @urb: an URB associated with the failed or incomplete split transaction
 *
 * High speed HCDs use this to tell the hub driver that some split control or
 * bulk transaction failed in a way that requires clearing internal state of
 * a transaction translator.  This is normally detected (and reported) from
 * interrupt context.
 *
 * It may not be possible for that hub to handle additional full (or low)
 * speed transactions until that state is fully cleared out.
 */
int usb_hub_clear_tt_buffer(struct urb *urb)
{
	struct usb_device	*udev = urb->dev;
	int			pipe = urb->pipe;
	struct usb_tt		*tt = udev->tt;
	unsigned long		flags;
	struct usb_tt_clear	*clear;

	/* we've got to cope with an arbitrary number of pending TT clears,
	 * since each TT has "at least two" buffers that can need it (and
	 * there can be many TTs per hub).  even if they're uncommon.
	 */
	if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) {
		dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
		/* FIXME recover somehow ... RESET_TT? */
		return -ENOMEM;
	}

	/* info that CLEAR_TT_BUFFER needs */
	clear->tt = tt->multi ? udev->ttport : 1;
	clear->devinfo = usb_pipeendpoint (pipe);
	clear->devinfo |= udev->devnum << 4;
	clear->devinfo |= usb_pipecontrol (pipe)
			? (USB_ENDPOINT_XFER_CONTROL << 11)
			: (USB_ENDPOINT_XFER_BULK << 11);
	if (usb_pipein (pipe))
		clear->devinfo |= 1 << 15;

	/* info for completion callback */
	clear->hcd = bus_to_hcd(udev->bus);
	clear->ep = urb->ep;

	/* tell keventd to clear state for this TT */
	spin_lock_irqsave (&tt->lock, flags);
	list_add_tail (&clear->clear_list, &tt->clear_list);
	schedule_work(&tt->clear_work);
	spin_unlock_irqrestore (&tt->lock, flags);
	return 0;
}
EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer);

/* If do_delay is false, return the number of milliseconds the caller
 * needs to delay.
 */
static unsigned hub_power_on(struct usb_hub *hub, bool do_delay)
{
	int port1;
	unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
	unsigned delay;
	u16 wHubCharacteristics =
			le16_to_cpu(hub->descriptor->wHubCharacteristics);

	/* Enable power on each port.  Some hubs have reserved values
	 * of LPSM (> 2) in their descriptors, even though they are
	 * USB 2.0 hubs.  Some hubs do not implement port-power switching
	 * but only emulate it.  In all cases, the ports won't work
	 * unless we send these messages to the hub.
	 */
	if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2)
		dev_dbg(hub->intfdev, "enabling power on all ports\n");
	else
		dev_dbg(hub->intfdev, "trying to enable port power on "
				"non-switchable hub\n");
	for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
		set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);

	/* Wait at least 100 msec for power to become stable */
	delay = max(pgood_delay, (unsigned) 100);
	if (do_delay)
		msleep(delay);
	return delay;
}

static int hub_hub_status(struct usb_hub *hub,
		u16 *status, u16 *change)
{
	int ret;

	mutex_lock(&hub->status_mutex);
	ret = get_hub_status(hub->hdev, &hub->status->hub);
	if (ret < 0)
		dev_err (hub->intfdev,
			"%s failed (err = %d)\n", __func__, ret);
	else {
		*status = le16_to_cpu(hub->status->hub.wHubStatus);
		*change = le16_to_cpu(hub->status->hub.wHubChange); 
		ret = 0;
	}
	mutex_unlock(&hub->status_mutex);
	return ret;
}

static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
{
	struct usb_device *hdev = hub->hdev;
	int ret = 0;

	if (hdev->children[port1-1] && set_state)
		usb_set_device_state(hdev->children[port1-1],
				USB_STATE_NOTATTACHED);
	if (!hub->error && !hub_is_superspeed(hub->hdev))
		ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
	if (ret)
		dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
				port1, ret);
	return ret;
}

/*
 * Disable a port and mark a logical connect-change event, so that some
 * time later khubd will disconnect() any existing usb_device on the port
 * and will re-enumerate if there actually is a device attached.
 */
static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
{
	dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
	hub_port_disable(hub, port1, 1);

	/* FIXME let caller ask to power down the port:
	 *  - some devices won't enumerate without a VBUS power cycle
	 *  - SRP saves power that way
	 *  - ... new call, TBD ...
	 * That's easy if this hub can switch power per-port, and
	 * khubd reactivates the port later (timer, SRP, etc).
	 * Powerdown must be optional, because of reset/DFU.
	 */

	set_bit(port1, hub->change_bits);
 	kick_khubd(hub);
}

/**
 * usb_remove_device - disable a device's port on its parent hub
 * @udev: device to be disabled and removed
 * Context: @udev locked, must be able to sleep.
 *
 * After @udev's port has been disabled, khubd is notified and it will
 * see that the device has been disconnected.  When the device is
 * physically unplugged and something is plugged in, the events will
 * be received and processed normally.
 */
int usb_remove_device(struct usb_device *udev)
{
	struct usb_hub *hub;
	struct usb_interface *intf;

	if (!udev->parent)	/* Can't remove a root hub */
		return -EINVAL;
	hub = hdev_to_hub(udev->parent);
	intf = to_usb_interface(hub->intfdev);

	usb_autopm_get_interface(intf);
	set_bit(udev->portnum, hub->removed_bits);
	hub_port_logical_disconnect(hub, udev->portnum);
	usb_autopm_put_interface(intf);
	return 0;
}

enum hub_activation_type {
	HUB_INIT, HUB_INIT2, HUB_INIT3,		/* INITs must come first */
	HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
};

static void hub_init_func2(struct work_struct *ws);
static void hub_init_func3(struct work_struct *ws);

static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
{
	struct usb_device *hdev = hub->hdev;
	struct usb_hcd *hcd;
	int ret;
	int port1;
	int status;
	bool need_debounce_delay = false;
	unsigned delay;

	/* Continue a partial initialization */
	if (type == HUB_INIT2)
		goto init2;
	if (type == HUB_INIT3)
		goto init3;

	/* After a resume, port power should still be on.
	 * For any other type of activation, turn it on.
	 */
	if (type != HUB_RESUME) {

		/* Speed up system boot by using a delayed_work for the
		 * hub's initial power-up delays.  This is pretty awkward
		 * and the implementation looks like a home-brewed sort of
		 * setjmp/longjmp, but it saves at least 100 ms for each
		 * root hub (assuming usbcore is compiled into the kernel
		 * rather than as a module).  It adds up.
		 *
		 * This can't be done for HUB_RESUME or HUB_RESET_RESUME
		 * because for those activation types the ports have to be
		 * operational when we return.  In theory this could be done
		 * for HUB_POST_RESET, but it's easier not to.
		 */
		if (type == HUB_INIT) {
			delay = hub_power_on(hub, false);
			PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
			schedule_delayed_work(&hub->init_work,
					msecs_to_jiffies(delay));

			/* Suppress autosuspend until init is done */
			usb_autopm_get_interface_no_resume(
					to_usb_interface(hub->intfdev));
			return;		/* Continues at init2: below */
		} else if (type == HUB_RESET_RESUME) {
			/* The internal host controller state for the hub device
			 * may be gone after a host power loss on system resume.
			 * Update the device's info so the HW knows it's a hub.
			 */
			hcd = bus_to_hcd(hdev->bus);
			if (hcd->driver->update_hub_device) {
				ret = hcd->driver->update_hub_device(hcd, hdev,
						&hub->tt, GFP_NOIO);
				if (ret < 0) {
					dev_err(hub->intfdev, "Host not "
							"accepting hub info "
							"update.\n");
					dev_err(hub->intfdev, "LS/FS devices "
							"and hubs may not work "
							"under this hub\n.");
				}
			}
			hub_power_on(hub, true);
		} else {
			hub_power_on(hub, true);
		}
	}
 init2:

	/* Check each port and set hub->change_bits to let khubd know
	 * which ports need attention.
	 */
	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
		struct usb_device *udev = hdev->children[port1-1];
		u16 portstatus, portchange;

		portstatus = portchange = 0;
		status = hub_port_status(hub, port1, &portstatus, &portchange);
		if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
			dev_dbg(hub->intfdev,
					"port %d: status %04x change %04x\n",
					port1, portstatus, portchange);

		/* After anything other than HUB_RESUME (i.e., initialization
		 * or any sort of reset), every port should be disabled.
		 * Unconnected ports should likewise be disabled (paranoia),
		 * and so should ports for which we have no usb_device.
		 */
		if ((portstatus & USB_PORT_STAT_ENABLE) && (
				type != HUB_RESUME ||
				!(portstatus & USB_PORT_STAT_CONNECTION) ||
				!udev ||
				udev->state == USB_STATE_NOTATTACHED)) {
			/*
			 * USB3 protocol ports will automatically transition
			 * to Enabled state when detect an USB3.0 device attach.
			 * Do not disable USB3 protocol ports.
			 */
			if (!hub_is_superspeed(hdev)) {
				clear_port_feature(hdev, port1,
						   USB_PORT_FEAT_ENABLE);
				portstatus &= ~USB_PORT_STAT_ENABLE;
			} else {
				/* Pretend that power was lost for USB3 devs */
				portstatus &= ~USB_PORT_STAT_ENABLE;
			}
		}

		/* Clear status-change flags; we'll debounce later */
		if (portchange & USB_PORT_STAT_C_CONNECTION) {
			need_debounce_delay = true;
			clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_CONNECTION);
		}
		if (portchange & USB_PORT_STAT_C_ENABLE) {
			need_debounce_delay = true;
			clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_ENABLE);
		}
		if (portchange & USB_PORT_STAT_C_LINK_STATE) {
			need_debounce_delay = true;
			clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_PORT_LINK_STATE);
		}

		if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
				hub_is_superspeed(hub->hdev)) {
			need_debounce_delay = true;
			clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_BH_PORT_RESET);
		}
		/* We can forget about a "removed" device when there's a
		 * physical disconnect or the connect status changes.
		 */
		if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
				(portchange & USB_PORT_STAT_C_CONNECTION))
			clear_bit(port1, hub->removed_bits);

		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
			/* Tell khubd to disconnect the device or
			 * check for a new connection
			 */
			if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
				set_bit(port1, hub->change_bits);

		} else if (portstatus & USB_PORT_STAT_ENABLE) {
			/* The power session apparently survived the resume.
			 * If there was an overcurrent or suspend change
			 * (i.e., remote wakeup request), have khubd
			 * take care of it.
			 */
			if (portchange)
				set_bit(port1, hub->change_bits);

		} else if (udev->persist_enabled) {
#ifdef CONFIG_PM
			udev->reset_resume = 1;
#endif
			set_bit(port1, hub->change_bits);

		} else {
			/* The power session is gone; tell khubd */
			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
			set_bit(port1, hub->change_bits);
		}
	}

	/* If no port-status-change flags were set, we don't need any
	 * debouncing.  If flags were set we can try to debounce the
	 * ports all at once right now, instead of letting khubd do them
	 * one at a time later on.
	 *
	 * If any port-status changes do occur during this delay, khubd
	 * will see them later and handle them normally.
	 */
	if (need_debounce_delay) {
		delay = HUB_DEBOUNCE_STABLE;

		/* Don't do a long sleep inside a workqueue routine */
		if (type == HUB_INIT2) {
			PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3);
			schedule_delayed_work(&hub->init_work,
					msecs_to_jiffies(delay));
			return;		/* Continues at init3: below */
		} else {
			msleep(delay);
		}
	}
 init3:
	hub->quiescing = 0;

	status = usb_submit_urb(hub->urb, GFP_NOIO);
	if (status < 0)
		dev_err(hub->intfdev, "activate --> %d\n", status);
	if (hub->has_indicators && blinkenlights)
		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);

	/* Scan all ports that need attention */
	kick_khubd(hub);

	/* Allow autosuspend if it was suppressed */
	if (type <= HUB_INIT3)
		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
}

/* Implement the continuations for the delays above */
static void hub_init_func2(struct work_struct *ws)
{
	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);

	hub_activate(hub, HUB_INIT2);
}

static void hub_init_func3(struct work_struct *ws)
{
	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);

	hub_activate(hub, HUB_INIT3);
}

enum hub_quiescing_type {
	HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
};

static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
{
	struct usb_device *hdev = hub->hdev;
	int i;

	cancel_delayed_work_sync(&hub->init_work);

	/* khubd and related activity won't re-trigger */
	hub->quiescing = 1;

	if (type != HUB_SUSPEND) {
		/* Disconnect all the children */
		for (i = 0; i < hdev->maxchild; ++i) {
			if (hdev->children[i])
				usb_disconnect(&hdev->children[i]);
		}
	}

	/* Stop khubd and related activity */
	usb_kill_urb(hub->urb);
	if (hub->has_indicators)
		cancel_delayed_work_sync(&hub->leds);
	if (hub->tt.hub)
		cancel_work_sync(&hub->tt.clear_work);
}

/* caller has locked the hub device */
static int hub_pre_reset(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);

	hub_quiesce(hub, HUB_PRE_RESET);
	return 0;
}

/* caller has locked the hub device */
static int hub_post_reset(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);

	hub_activate(hub, HUB_POST_RESET);
	return 0;
}

static int hub_configure(struct usb_hub *hub,
	struct usb_endpoint_descriptor *endpoint)
{
	struct usb_hcd *hcd;
	struct usb_device *hdev = hub->hdev;
	struct device *hub_dev = hub->intfdev;
	u16 hubstatus, hubchange;
	u16 wHubCharacteristics;
	unsigned int pipe;
	int maxp, ret;
	char *message = "out of memory";

	hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
	if (!hub->buffer) {
		ret = -ENOMEM;
		goto fail;
	}

	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
	if (!hub->status) {
		ret = -ENOMEM;
		goto fail;
	}
	mutex_init(&hub->status_mutex);

	hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
	if (!hub->descriptor) {
		ret = -ENOMEM;
		goto fail;
	}

	if (hub_is_superspeed(hdev) && (hdev->parent != NULL)) {
		ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
				HUB_SET_DEPTH, USB_RT_HUB,
				hdev->level - 1, 0, NULL, 0,
				USB_CTRL_SET_TIMEOUT);

		if (ret < 0) {
			message = "can't set hub depth";
			goto fail;
		}
	}

	/* Request the entire hub descriptor.
	 * hub->descriptor can handle USB_MAXCHILDREN ports,
	 * but the hub can/will return fewer bytes here.
	 */
	ret = get_hub_descriptor(hdev, hub->descriptor);
	if (ret < 0) {
		message = "can't read hub descriptor";
		goto fail;
	} else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
		message = "hub has too many ports!";
		ret = -ENODEV;
		goto fail;
	}

	hdev->maxchild = hub->descriptor->bNbrPorts;
	dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
		(hdev->maxchild == 1) ? "" : "s");

	hub->port_owners = kzalloc(hdev->maxchild * sizeof(void *), GFP_KERNEL);
	if (!hub->port_owners) {
		ret = -ENOMEM;
		goto fail;
	}

	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);

	/* FIXME for USB 3.0, skip for now */
	if ((wHubCharacteristics & HUB_CHAR_COMPOUND) &&
			!(hub_is_superspeed(hdev))) {
		int	i;
		char	portstr [USB_MAXCHILDREN + 1];

		for (i = 0; i < hdev->maxchild; i++)
			portstr[i] = hub->descriptor->u.hs.DeviceRemovable
				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
				? 'F' : 'R';
		portstr[hdev->maxchild] = 0;
		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
	} else
		dev_dbg(hub_dev, "standalone hub\n");

	switch (wHubCharacteristics & HUB_CHAR_LPSM) {
		case 0x00:
			dev_dbg(hub_dev, "ganged power switching\n");
			break;
		case 0x01:
			dev_dbg(hub_dev, "individual port power switching\n");
			break;
		case 0x02:
		case 0x03:
			dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
			break;
	}

	switch (wHubCharacteristics & HUB_CHAR_OCPM) {
		case 0x00:
			dev_dbg(hub_dev, "global over-current protection\n");
			break;
		case 0x08:
			dev_dbg(hub_dev, "individual port over-current protection\n");
			break;
		case 0x10:
		case 0x18:
			dev_dbg(hub_dev, "no over-current protection\n");
                        break;
	}

	spin_lock_init (&hub->tt.lock);
	INIT_LIST_HEAD (&hub->tt.clear_list);
	INIT_WORK(&hub->tt.clear_work, hub_tt_work);
	switch (hdev->descriptor.bDeviceProtocol) {
		case 0:
			break;
		case 1:
			dev_dbg(hub_dev, "Single TT\n");
			hub->tt.hub = hdev;
			break;
		case 2:
			ret = usb_set_interface(hdev, 0, 1);
			if (ret == 0) {
				dev_dbg(hub_dev, "TT per port\n");
				hub->tt.multi = 1;
			} else
				dev_err(hub_dev, "Using single TT (err %d)\n",
					ret);
			hub->tt.hub = hdev;
			break;
		case 3:
			/* USB 3.0 hubs don't have a TT */
			break;
		default:
			dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
				hdev->descriptor.bDeviceProtocol);
			break;
	}

	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
	switch (wHubCharacteristics & HUB_CHAR_TTTT) {
		case HUB_TTTT_8_BITS:
			if (hdev->descriptor.bDeviceProtocol != 0) {
				hub->tt.think_time = 666;
				dev_dbg(hub_dev, "TT requires at most %d "
						"FS bit times (%d ns)\n",
					8, hub->tt.think_time);
			}
			break;
		case HUB_TTTT_16_BITS:
			hub->tt.think_time = 666 * 2;
			dev_dbg(hub_dev, "TT requires at most %d "
					"FS bit times (%d ns)\n",
				16, hub->tt.think_time);
			break;
		case HUB_TTTT_24_BITS:
			hub->tt.think_time = 666 * 3;
			dev_dbg(hub_dev, "TT requires at most %d "
					"FS bit times (%d ns)\n",
				24, hub->tt.think_time);
			break;
		case HUB_TTTT_32_BITS:
			hub->tt.think_time = 666 * 4;
			dev_dbg(hub_dev, "TT requires at most %d "
					"FS bit times (%d ns)\n",
				32, hub->tt.think_time);
			break;
	}

	/* probe() zeroes hub->indicator[] */
	if (wHubCharacteristics & HUB_CHAR_PORTIND) {
		hub->has_indicators = 1;
		dev_dbg(hub_dev, "Port indicators are supported\n");
	}

	dev_dbg(hub_dev, "power on to power good time: %dms\n",
		hub->descriptor->bPwrOn2PwrGood * 2);

	/* power budgeting mostly matters with bus-powered hubs,
	 * and battery-powered root hubs (may provide just 8 mA).
	 */
	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
	if (ret < 2) {
		message = "can't get hub status";
		goto fail;
	}
	le16_to_cpus(&hubstatus);
	if (hdev == hdev->bus->root_hub) {
		if (hdev->bus_mA == 0 || hdev->bus_mA >= 500)
			hub->mA_per_port = 500;
		else {
			hub->mA_per_port = hdev->bus_mA;
			hub->limited_power = 1;
		}
	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
			hub->descriptor->bHubContrCurrent);
		hub->limited_power = 1;
		if (hdev->maxchild > 0) {
			int remaining = hdev->bus_mA -
					hub->descriptor->bHubContrCurrent;

			if (remaining < hdev->maxchild * 100)
				dev_warn(hub_dev,
					"insufficient power available "
					"to use all downstream ports\n");
			hub->mA_per_port = 100;		/* 7.2.1.1 */
		}
	} else {	/* Self-powered external hub */
		/* FIXME: What about battery-powered external hubs that
		 * provide less current per port? */
		hub->mA_per_port = 500;
	}
	if (hub->mA_per_port < 500)
		dev_dbg(hub_dev, "%umA bus power budget for each child\n",
				hub->mA_per_port);

	/* Update the HCD's internal representation of this hub before khubd
	 * starts getting port status changes for devices under the hub.
	 */
	hcd = bus_to_hcd(hdev->bus);
	if (hcd->driver->update_hub_device) {
		ret = hcd->driver->update_hub_device(hcd, hdev,
				&hub->tt, GFP_KERNEL);
		if (ret < 0) {
			message = "can't update HCD hub info";
			goto fail;
		}
	}

	ret = hub_hub_status(hub, &hubstatus, &hubchange);
	if (ret < 0) {
		message = "can't get hub status";
		goto fail;
	}

	/* local power status reports aren't always correct */
	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
		dev_dbg(hub_dev, "local power source is %s\n",
			(hubstatus & HUB_STATUS_LOCAL_POWER)
			? "lost (inactive)" : "good");

	if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
		dev_dbg(hub_dev, "%sover-current condition exists\n",
			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");

	/* set up the interrupt endpoint
	 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
	 * bytes as USB2.0[11.12.3] says because some hubs are known
	 * to send more data (and thus cause overflow). For root hubs,
	 * maxpktsize is defined in hcd.c's fake endpoint descriptors
	 * to be big enough for at least USB_MAXCHILDREN ports. */
	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
	maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));

	if (maxp > sizeof(*hub->buffer))
		maxp = sizeof(*hub->buffer);

	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!hub->urb) {
		ret = -ENOMEM;
		goto fail;
	}

	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
		hub, endpoint->bInterval);

	/* maybe cycle the hub leds */
	if (hub->has_indicators && blinkenlights)
		hub->indicator [0] = INDICATOR_CYCLE;

	hub_activate(hub, HUB_INIT);
	return 0;

fail:
	dev_err (hub_dev, "config failed, %s (err %d)\n",
			message, ret);
	/* hub_disconnect() frees urb and descriptor */
	return ret;
}

static void hub_release(struct kref *kref)
{
	struct usb_hub *hub = container_of(kref, struct usb_hub, kref);

	usb_put_intf(to_usb_interface(hub->intfdev));
	kfree(hub);
}

static unsigned highspeed_hubs;

static void hub_disconnect(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata (intf);

	/* Take the hub off the event list and don't let it be added again */
	spin_lock_irq(&hub_event_lock);
	if (!list_empty(&hub->event_list)) {
		list_del_init(&hub->event_list);
		usb_autopm_put_interface_no_suspend(intf);
	}
	hub->disconnected = 1;
	spin_unlock_irq(&hub_event_lock);

	/* Disconnect all children and quiesce the hub */
	hub->error = 0;
	hub_quiesce(hub, HUB_DISCONNECT);

	usb_set_intfdata (intf, NULL);
	hub->hdev->maxchild = 0;

	if (hub->hdev->speed == USB_SPEED_HIGH)
		highspeed_hubs--;

	usb_free_urb(hub->urb);
	kfree(hub->port_owners);
	kfree(hub->descriptor);
	kfree(hub->status);
	kfree(hub->buffer);

	kref_put(&hub->kref, hub_release);
}

static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
	struct usb_host_interface *desc;
	struct usb_endpoint_descriptor *endpoint;
	struct usb_device *hdev;
	struct usb_hub *hub;

	desc = intf->cur_altsetting;
	hdev = interface_to_usbdev(intf);

	/* Hubs have proper suspend/resume support.  USB 3.0 device suspend is
	 * different from USB 2.0/1.1 device suspend, and unfortunately we
	 * don't support it yet.  So leave autosuspend disabled for USB 3.0
	 * external hubs for now.  Enable autosuspend for USB 3.0 roothubs,
	 * since that isn't a "real" hub.
	 */
	if (!hub_is_superspeed(hdev) || !hdev->parent)
		usb_enable_autosuspend(hdev);

	if (hdev->level == MAX_TOPO_LEVEL) {
		dev_err(&intf->dev,
			"Unsupported bus topology: hub nested too deep\n");
		return -E2BIG;
	}

#ifdef	CONFIG_USB_OTG_BLACKLIST_HUB
	if (hdev->parent) {
		dev_warn(&intf->dev, "ignoring external hub\n");
		return -ENODEV;
	}
#endif

	/* Some hubs have a subclass of 1, which AFAICT according to the */
	/*  specs is not defined, but it works */
	if ((desc->desc.bInterfaceSubClass != 0) &&
	    (desc->desc.bInterfaceSubClass != 1)) {
descriptor_error:
		dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
		return -EIO;
	}

	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
	if (desc->desc.bNumEndpoints != 1)
		goto descriptor_error;

	endpoint = &desc->endpoint[0].desc;

	/* If it's not an interrupt in endpoint, we'd better punt! */
	if (!usb_endpoint_is_int_in(endpoint))
		goto descriptor_error;

	/* We found a hub */
	dev_info (&intf->dev, "USB hub found\n");

	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
	if (!hub) {
		dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
		return -ENOMEM;
	}

	kref_init(&hub->kref);
	INIT_LIST_HEAD(&hub->event_list);
	hub->intfdev = &intf->dev;
	hub->hdev = hdev;
	INIT_DELAYED_WORK(&hub->leds, led_work);
	INIT_DELAYED_WORK(&hub->init_work, NULL);
	usb_get_intf(intf);

	usb_set_intfdata (intf, hub);
	intf->needs_remote_wakeup = 1;

	if (hdev->speed == USB_SPEED_HIGH)
		highspeed_hubs++;

	if (hub_configure(hub, endpoint) >= 0)
		return 0;

	hub_disconnect (intf);
	return -ENODEV;
}

/* No BKL needed */
static int
hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
{
	struct usb_device *hdev = interface_to_usbdev (intf);

	/* assert ifno == 0 (part of hub spec) */
	switch (code) {
	case USBDEVFS_HUB_PORTINFO: {
		struct usbdevfs_hub_portinfo *info = user_data;
		int i;

		spin_lock_irq(&device_state_lock);
		if (hdev->devnum <= 0)
			info->nports = 0;
		else {
			info->nports = hdev->maxchild;
			for (i = 0; i < info->nports; i++) {
				if (hdev->children[i] == NULL)
					info->port[i] = 0;
				else
					info->port[i] =
						hdev->children[i]->devnum;
			}
		}
		spin_unlock_irq(&device_state_lock);

		return info->nports + 1;
		}

	default:
		return -ENOSYS;
	}
}

/*
 * Allow user programs to claim ports on a hub.  When a device is attached
 * to one of these "claimed" ports, the program will "own" the device.
 */
static int find_port_owner(struct usb_device *hdev, unsigned port1,
		void ***ppowner)
{
	if (hdev->state == USB_STATE_NOTATTACHED)
		return -ENODEV;
	if (port1 == 0 || port1 > hdev->maxchild)
		return -EINVAL;

	/* This assumes that devices not managed by the hub driver
	 * will always have maxchild equal to 0.
	 */
	*ppowner = &(hdev_to_hub(hdev)->port_owners[port1 - 1]);
	return 0;
}

/* In the following three functions, the caller must hold hdev's lock */
int usb_hub_claim_port(struct usb_device *hdev, unsigned port1, void *owner)
{
	int rc;
	void **powner;

	rc = find_port_owner(hdev, port1, &powner);
	if (rc)
		return rc;
	if (*powner)
		return -EBUSY;
	*powner = owner;
	return rc;
}

int usb_hub_release_port(struct usb_device *hdev, unsigned port1, void *owner)
{
	int rc;
	void **powner;

	rc = find_port_owner(hdev, port1, &powner);
	if (rc)
		return rc;
	if (*powner != owner)
		return -ENOENT;
	*powner = NULL;
	return rc;
}

void usb_hub_release_all_ports(struct usb_device *hdev, void *owner)
{
	int n;
	void **powner;

	n = find_port_owner(hdev, 1, &powner);
	if (n == 0) {
		for (; n < hdev->maxchild; (++n, ++powner)) {
			if (*powner == owner)
				*powner = NULL;
		}
	}
}

/* The caller must hold udev's lock */
bool usb_device_is_owned(struct usb_device *udev)
{
	struct usb_hub *hub;

	if (udev->state == USB_STATE_NOTATTACHED || !udev->parent)
		return false;
	hub = hdev_to_hub(udev->parent);
	return !!hub->port_owners[udev->portnum - 1];
}


static void recursively_mark_NOTATTACHED(struct usb_device *udev)
{
	int i;

	for (i = 0; i < udev->maxchild; ++i) {
		if (udev->children[i])
			recursively_mark_NOTATTACHED(udev->children[i]);
	}
	if (udev->state == USB_STATE_SUSPENDED)
		udev->active_duration -= jiffies;
	udev->state = USB_STATE_NOTATTACHED;
}

/**
 * usb_set_device_state - change a device's current state (usbcore, hcds)
 * @udev: pointer to device whose state should be changed
 * @new_state: new state value to be stored
 *
 * udev->state is _not_ fully protected by the device lock.  Although
 * most transitions are made only while holding the lock, the state can
 * can change to USB_STATE_NOTATTACHED at almost any time.  This
 * is so that devices can be marked as disconnected as soon as possible,
 * without having to wait for any semaphores to be released.  As a result,
 * all changes to any device's state must be protected by the
 * device_state_lock spinlock.
 *
 * Once a device has been added to the device tree, all changes to its state
 * should be made using this routine.  The state should _not_ be set directly.
 *
 * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
 * Otherwise udev->state is set to new_state, and if new_state is
 * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
 * to USB_STATE_NOTATTACHED.
 */
void usb_set_device_state(struct usb_device *udev,
		enum usb_device_state new_state)
{
	unsigned long flags;
	int wakeup = -1;

	spin_lock_irqsave(&device_state_lock, flags);
	if (udev->state == USB_STATE_NOTATTACHED)
		;	/* do nothing */
	else if (new_state != USB_STATE_NOTATTACHED) {

		/* root hub wakeup capabilities are managed out-of-band
		 * and may involve silicon errata ... ignore them here.
		 */
		if (udev->parent) {
			if (udev->state == USB_STATE_SUSPENDED
					|| new_state == USB_STATE_SUSPENDED)
				;	/* No change to wakeup settings */
			else if (new_state == USB_STATE_CONFIGURED)
				wakeup = udev->actconfig->desc.bmAttributes
					 & USB_CONFIG_ATT_WAKEUP;
			else
				wakeup = 0;
		}
		if (udev->state == USB_STATE_SUSPENDED &&
			new_state != USB_STATE_SUSPENDED)
			udev->active_duration -= jiffies;
		else if (new_state == USB_STATE_SUSPENDED &&
				udev->state != USB_STATE_SUSPENDED)
			udev->active_duration += jiffies;
		udev->state = new_state;
	} else
		recursively_mark_NOTATTACHED(udev);
	spin_unlock_irqrestore(&device_state_lock, flags);
	if (wakeup >= 0)
		device_set_wakeup_capable(&udev->dev, wakeup);
}
EXPORT_SYMBOL_GPL(usb_set_device_state);

/*
 * Choose a device number.
 *
 * Device numbers are used as filenames in usbfs.  On USB-1.1 and
 * USB-2.0 buses they are also used as device addresses, however on
 * USB-3.0 buses the address is assigned by the controller hardware
 * and it usually is not the same as the device number.
 *
 * WUSB devices are simple: they have no hubs behind, so the mapping
 * device <-> virtual port number becomes 1:1. Why? to simplify the
 * life of the device connection logic in
 * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
 * handshake we need to assign a temporary address in the unauthorized
 * space. For simplicity we use the first virtual port number found to
 * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
 * and that becomes it's address [X < 128] or its unauthorized address
 * [X | 0x80].
 *
 * We add 1 as an offset to the one-based USB-stack port number
 * (zero-based wusb virtual port index) for two reasons: (a) dev addr
 * 0 is reserved by USB for default address; (b) Linux's USB stack
 * uses always #1 for the root hub of the controller. So USB stack's
 * port #1, which is wusb virtual-port #0 has address #2.
 *
 * Devices connected under xHCI are not as simple.  The host controller
 * supports virtualization, so the hardware assigns device addresses and
 * the HCD must setup data structures before issuing a set address
 * command to the hardware.
 */
static void choose_devnum(struct usb_device *udev)
{
	int		devnum;
	struct usb_bus	*bus = udev->bus;

	/* If khubd ever becomes multithreaded, this will need a lock */
	if (udev->wusb) {
		devnum = udev->portnum + 1;
		BUG_ON(test_bit(devnum, bus->devmap.devicemap));
	} else {
		/* Try to allocate the next devnum beginning at
		 * bus->devnum_next. */
		devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
					    bus->devnum_next);
		if (devnum >= 128)
			devnum = find_next_zero_bit(bus->devmap.devicemap,
						    128, 1);
		bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
	}
	if (devnum < 128) {
		set_bit(devnum, bus->devmap.devicemap);
		udev->devnum = devnum;
	}
}

static void release_devnum(struct usb_device *udev)
{
	if (udev->devnum > 0) {
		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
		udev->devnum = -1;
	}
}

static void update_devnum(struct usb_device *udev, int devnum)
{
	/* The address for a WUSB device is managed by wusbcore. */
	if (!udev->wusb)
		udev->devnum = devnum;
}

static void hub_free_dev(struct usb_device *udev)
{
	struct usb_hcd *hcd = bus_to_hcd(udev->bus);

	/* Root hubs aren't real devices, so don't free HCD resources */
	if (hcd->driver->free_dev && udev->parent)
		hcd->driver->free_dev(hcd, udev);
}

/**
 * usb_disconnect - disconnect a device (usbcore-internal)
 * @pdev: pointer to device being disconnected
 * Context: !in_interrupt ()
 *
 * Something got disconnected. Get rid of it and all of its children.
 *
 * If *pdev is a normal device then the parent hub must already be locked.
 * If *pdev is a root hub then this routine will acquire the
 * usb_bus_list_lock on behalf of the caller.
 *
 * Only hub drivers (including virtual root hub drivers for host
 * controllers) should ever call this.
 *
 * This call is synchronous, and may not be used in an interrupt context.
 */
void usb_disconnect(struct usb_device **pdev)
{
	struct usb_device	*udev = *pdev;
	int			i;
	struct usb_hcd		*hcd = bus_to_hcd(udev->bus);

	if (!udev) {
		pr_debug ("%s nodev\n", __func__);
		return;
	}

	/* mark the device as inactive, so any further urb submissions for
	 * this device (and any of its children) will fail immediately.
	 * this quiesces everything except pending urbs.
	 */
	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
	dev_info(&udev->dev, "USB disconnect, device number %d\n",
			udev->devnum);

	usb_lock_device(udev);

	/* Free up all the children before we remove this device */
	for (i = 0; i < USB_MAXCHILDREN; i++) {
		if (udev->children[i])
			usb_disconnect(&udev->children[i]);
	}

	/* deallocate hcd/hardware state ... nuking all pending urbs and
	 * cleaning up all state associated with the current configuration
	 * so that the hardware is now fully quiesced.
	 */
	dev_dbg (&udev->dev, "unregistering device\n");
	mutex_lock(hcd->bandwidth_mutex);
	usb_disable_device(udev, 0);
	mutex_unlock(hcd->bandwidth_mutex);
	usb_hcd_synchronize_unlinks(udev);

	usb_remove_ep_devs(&udev->ep0);
	usb_unlock_device(udev);

	/* Unregister the device.  The device driver is responsible
	 * for de-configuring the device and invoking the remove-device
	 * notifier chain (used by usbfs and possibly others).
	 */
	device_del(&udev->dev);

	/* Free the device number and delete the parent's children[]
	 * (or root_hub) pointer.
	 */
	release_devnum(udev);

	/* Avoid races with recursively_mark_NOTATTACHED() */
	spin_lock_irq(&device_state_lock);
	*pdev = NULL;
	spin_unlock_irq(&device_state_lock);

	hub_free_dev(udev);

	put_device(&udev->dev);
}

#ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
static void show_string(struct usb_device *udev, char *id, char *string)
{
	if (!string)
		return;
	dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
}

static void announce_device(struct usb_device *udev)
{
	dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
		le16_to_cpu(udev->descriptor.idVendor),
		le16_to_cpu(udev->descriptor.idProduct));
	dev_info(&udev->dev,
		"New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
		udev->descriptor.iManufacturer,
		udev->descriptor.iProduct,
		udev->descriptor.iSerialNumber);
	show_string(udev, "Product", udev->product);
	show_string(udev, "Manufacturer", udev->manufacturer);
	show_string(udev, "SerialNumber", udev->serial);
}
#else
static inline void announce_device(struct usb_device *udev) { }
#endif

#ifdef	CONFIG_USB_OTG
#include "otg_whitelist.h"
#endif

/**
 * usb_enumerate_device_otg - FIXME (usbcore-internal)
 * @udev: newly addressed device (in ADDRESS state)
 *
 * Finish enumeration for On-The-Go devices
 */
static int usb_enumerate_device_otg(struct usb_device *udev)
{
	int err = 0;

#ifdef	CONFIG_USB_OTG
	/*
	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
	 * to wake us after we've powered off VBUS; and HNP, switching roles
	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
	 */
	if (!udev->bus->is_b_host
			&& udev->config
			&& udev->parent == udev->…