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linux/drivers/usb/core/hub.c
Alan Stern c08512c761 USB: improve uses of usb_mark_last_busy 
This patch (as1434) cleans up the uses of usb_mark_last_busy() in
usbcore.  The function will be called when a device is resumed and
whenever a usage count is decremented.  A call that was missing from
the hub driver is added: A hub is used whenever one of its ports gets
suspended (this prevents hubs from suspending immediately after their
last child).

In addition, the call to disable autosuspend support for new devices
by default is moved from usb_detect_quirks() (where it doesn't really
belong) into usb_new_device() along with all the other runtime-PM
initializations.  Finally, an extra pm_runtime_get_noresume() is added
to prevent new devices from autosuspending while they are being
registered.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-16 14:04:22 -08:00

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/*
* 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;
};
/* 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(int portstatus)
{
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 if (portstatus & USB_PORT_STAT_SUPER_SPEED)
return "5.0 Gb/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 size)
{
int i, ret;
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,
USB_DT_HUB << 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; 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; 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)
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 connnect-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;
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 {
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.
* FIXME: USB3 root hub and external hubs are treated
* differently here.
*/
if (hdev->descriptor.bDeviceProtocol != 3 ||
(!hdev->parent &&
!(portstatus & USB_PORT_STAT_SUPER_SPEED))) {
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);
}
/* 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;
}
/* 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,
sizeof(*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);
if (wHubCharacteristics & HUB_CHAR_COMPOUND) {
int i;
char portstr [USB_MAXCHILDREN + 1];
for (i = 0; i < hdev->maxchild; i++)
portstr[i] = hub->descriptor->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_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;
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)
device_set_wakeup_capable(&udev->dev,
(udev->actconfig->desc.bmAttributes
& USB_CONFIG_ATT_WAKEUP));
else
device_set_wakeup_capable(&udev->dev, 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);
}
EXPORT_SYMBOL_GPL(usb_set_device_state);
/*
* 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_address(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_address(struct usb_device *udev)
{
if (udev->devnum > 0) {
clear_bit(udev->devnum, udev->bus->devmap.devicemap);
udev->devnum = -1;
}
}
static void update_address(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;
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 everyting except pending urbs.
*/
usb_set_device_state(udev, USB_STATE_NOTATTACHED);
dev_info (&udev->dev, "USB disconnect, address %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");
usb_disable_device(udev, 0);
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_address(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->bus->root_hub) {
struct usb_otg_descriptor *desc = NULL;
struct usb_bus *bus = udev->bus;
/* descriptor may appear anywhere in config */
if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
le16_to_cpu(udev->config[0].desc.wTotalLength),
USB_DT_OTG, (void **) &desc) == 0) {
if (desc->bmAttributes & USB_OTG_HNP) {
unsigned port1 = udev->portnum;
dev_info(&udev->dev,
"Dual-Role OTG device on %sHNP port\n",
(port1 == bus->otg_port)
? "" : "non-");
/* enable HNP before suspend, it's simpler */
if (port1 == bus->otg_port)
bus->b_hnp_enable = 1;
err = usb_control_msg(udev,
usb_sndctrlpipe(udev, 0),
USB_REQ_SET_FEATURE, 0,
bus->b_hnp_enable
? USB_DEVICE_B_HNP_ENABLE
: USB_DEVICE_A_ALT_HNP_SUPPORT,
0, NULL, 0, USB_CTRL_SET_TIMEOUT);
if (err < 0) {
/* OTG MESSAGE: report errors here,
* customize to match your product.
*/
dev_info(&udev->dev,
"can't set HNP mode: %d\n",
err);
bus->b_hnp_enable = 0;
}
}
}
}
if (!is_targeted(udev)) {
/* Maybe it can talk to us, though we can't talk to it.
* (Includes HNP test device.)
*/
if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
err = usb_port_suspend(udev, PMSG_SUSPEND);
if (err < 0)
dev_dbg(&udev->dev, "HNP fail, %d\n", err);
}
err = -ENOTSUPP;
goto fail;
}
fail:
#endif
return err;
}
/**
* usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal)
* @udev: newly addressed device (in ADDRESS state)
*
* This is only called by usb_new_device() and usb_authorize_device()
* and FIXME -- all comments that apply to them apply here wrt to
* environment.
*
* If the device is WUSB and not authorized, we don't attempt to read
* the string descriptors, as they will be errored out by the device
* until it has been authorized.
*/
static int usb_enumerate_device(struct usb_device *udev)
{
int err;
if (udev->config == NULL) {
err = usb_get_configuration(udev);
if (err < 0) {
dev_err(&udev->dev, "can't read configurations, error %d\n",
err);
goto fail;
}
}
if (udev->wusb == 1 && udev->authorized == 0) {
udev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
udev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
udev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
}
else {
/* read the standard strings and cache them if present */
udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
udev->manufacturer = usb_cache_string(udev,
udev->descriptor.iManufacturer);
udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
}
err = usb_enumerate_device_otg(udev);
fail:
return err;
}
/**
* usb_new_device - perform initial device setup (usbcore-internal)
* @udev: newly addressed device (in ADDRESS state)
*
* This is called with devices which have been detected but not fully
* enumerated. The device descriptor is available, but not descriptors
* for any device configuration. The caller must have locked either
* the parent hub (if udev is a normal device) or else the
* usb_bus_list_lock (if udev is a root hub). The parent's pointer to
* udev has already been installed, but udev is not yet visible through
* sysfs or other filesystem code.
*
* It will return if the device is configured properly or not. Zero if
* the interface was registered with the driver core; else a negative
* errno value.
*
* This call is synchronous, and may not be used in an interrupt context.
*
* Only the hub driver or root-hub registrar should ever call this.
*/
int usb_new_device(struct usb_device *udev)
{
int err;
if (udev->parent) {
/* Initialize non-root-hub device wakeup to disabled;
* device (un)configuration controls wakeup capable
* sysfs power/wakeup controls wakeup enabled/disabled
*/
device_init_wakeup(&udev->dev, 0);
}
/* Tell the runtime-PM framework the device is active */
pm_runtime_set_active(&udev->dev);
pm_runtime_get_noresume(&udev->dev);
pm_runtime_use_autosuspend(&udev->dev);
pm_runtime_enable(&udev->dev);
/* By default, forbid autosuspend for all devices. It will be
* allowed for hubs during binding.
*/
usb_disable_autosuspend(udev);
err = usb_enumerate_device(udev); /* Read descriptors */
if (err < 0)
goto fail;
dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n",
udev->devnum, udev->bus->busnum,
(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
/* export the usbdev device-node for libusb */
udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
/* Tell the world! */
announce_device(udev);
device_enable_async_suspend(&udev->dev);
/* Register the device. The device driver is responsible
* for configuring the device and invoking the add-device
* notifier chain (used by usbfs and possibly others).
*/
err = device_add(&udev->dev);
if (err) {
dev_err(&udev->dev, "can't device_add, error %d\n", err);
goto fail;
}
(void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
usb_mark_last_busy(udev);
pm_runtime_put_sync_autosuspend(&udev->dev);
return err;
fail:
usb_set_device_state(udev, USB_STATE_NOTATTACHED);
pm_runtime_disable(&udev->dev);
pm_runtime_set_suspended(&udev->dev);
return err;
}
/**
* usb_deauthorize_device - deauthorize a device (usbcore-internal)
* @usb_dev: USB device
*
* Move the USB device to a very basic state where interfaces are disabled
* and the device is in fact unconfigured and unusable.
*
* We share a lock (that we have) with device_del(), so we need to
* defer its call.
*/
int usb_deauthorize_device(struct usb_device *usb_dev)
{
usb_lock_device(usb_dev);
if (usb_dev->authorized == 0)
goto out_unauthorized;
usb_dev->authorized = 0;
usb_set_configuration(usb_dev, -1);
kfree(usb_dev->product);
usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
kfree(usb_dev->manufacturer);
usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
kfree(usb_dev->serial);
usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
usb_destroy_configuration(usb_dev);
usb_dev->descriptor.bNumConfigurations = 0;
out_unauthorized:
usb_unlock_device(usb_dev);
return 0;
}
int usb_authorize_device(struct usb_device *usb_dev)
{
int result = 0, c;
usb_lock_device(usb_dev);
if (usb_dev->authorized == 1)
goto out_authorized;
result = usb_autoresume_device(usb_dev);
if (result < 0) {
dev_err(&usb_dev->dev,
"can't autoresume for authorization: %d\n", result);
goto error_autoresume;
}
result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
if (result < 0) {
dev_err(&usb_dev->dev, "can't re-read device descriptor for "
"authorization: %d\n", result);
goto error_device_descriptor;
}
kfree(usb_dev->product);
usb_dev->product = NULL;
kfree(usb_dev->manufacturer);
usb_dev->manufacturer = NULL;
kfree(usb_dev->serial);
usb_dev->serial = NULL;
usb_dev->authorized = 1;
result = usb_enumerate_device(usb_dev);
if (result < 0)
goto error_enumerate;
/* Choose and set the configuration. This registers the interfaces
* with the driver core and lets interface drivers bind to them.
*/
c = usb_choose_configuration(usb_dev);
if (c >= 0) {
result = usb_set_configuration(usb_dev, c);
if (result) {
dev_err(&usb_dev->dev,
"can't set config #%d, error %d\n", c, result);
/* This need not be fatal. The user can try to
* set other configurations. */
}
}
dev_info(&usb_dev->dev, "authorized to connect\n");
error_enumerate:
error_device_descriptor:
usb_autosuspend_device(usb_dev);
error_autoresume:
out_authorized:
usb_unlock_device(usb_dev); // complements locktree
return result;
}
/* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
static unsigned hub_is_wusb(struct usb_hub *hub)
{
struct usb_hcd *hcd;
if (hub->hdev->parent != NULL) /* not a root hub? */
return 0;
hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
return hcd->wireless;
}
#define PORT_RESET_TRIES 5
#define SET_ADDRESS_TRIES 2
#define GET_DESCRIPTOR_TRIES 2
#define SET_CONFIG_TRIES (2 * (use_both_schemes + 1))
#define USE_NEW_SCHEME(i) ((i) / 2 == old_scheme_first)
#define HUB_ROOT_RESET_TIME 50 /* times are in msec */
#define HUB_SHORT_RESET_TIME 10
#define HUB_LONG_RESET_TIME 200
#define HUB_RESET_TIMEOUT 500
static int hub_port_wait_reset(struct usb_hub *hub, int port1,
struct usb_device *udev, unsigned int delay)
{
int delay_time, ret;
u16 portstatus;
u16 portchange;
for (delay_time = 0;
delay_time < HUB_RESET_TIMEOUT;
delay_time += delay) {
/* wait to give the device a chance to reset */
msleep(delay);
/* read and decode port status */
ret = hub_port_status(hub, port1, &portstatus, &portchange);
if (ret < 0)
return ret;
/* Device went away? */
if (!(portstatus & USB_PORT_STAT_CONNECTION))
return -ENOTCONN;
/* bomb out completely if the connection bounced */
if ((portchange & USB_PORT_STAT_C_CONNECTION))
return -ENOTCONN;
/* if we`ve finished resetting, then break out of the loop */
if (!(portstatus & USB_PORT_STAT_RESET) &&
(portstatus & USB_PORT_STAT_ENABLE)) {
if (hub_is_wusb(hub))
udev->speed = USB_SPEED_WIRELESS;
else if (portstatus & USB_PORT_STAT_SUPER_SPEED)
udev->speed = USB_SPEED_SUPER;
else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
udev->speed = USB_SPEED_HIGH;
else if (portstatus & USB_PORT_STAT_LOW_SPEED)
udev->speed = USB_SPEED_LOW;
else
udev->speed = USB_SPEED_FULL;
return 0;
}
/* switch to the long delay after two short delay failures */
if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
delay = HUB_LONG_RESET_TIME;
dev_dbg (hub->intfdev,
"port %d not reset yet, waiting %dms\n",
port1, delay);
}
return -EBUSY;
}
static int hub_port_reset(struct usb_hub *hub, int port1,
struct usb_device *udev, unsigned int delay)
{
int i, status;
struct usb_hcd *hcd;
hcd = bus_to_hcd(udev->bus);
/* Block EHCI CF initialization during the port reset.
* Some companion controllers don't like it when they mix.
*/
down_read(&ehci_cf_port_reset_rwsem);
/* Reset the port */
for (i = 0; i < PORT_RESET_TRIES; i++) {
status = set_port_feature(hub->hdev,
port1, USB_PORT_FEAT_RESET);
if (status)
dev_err(hub->intfdev,
"cannot reset port %d (err = %d)\n",
port1, status);
else {
status = hub_port_wait_reset(hub, port1, udev, delay);
if (status && status != -ENOTCONN)
dev_dbg(hub->intfdev,
"port_wait_reset: err = %d\n",
status);
}
/* return on disconnect or reset */
switch (status) {
case 0:
/* TRSTRCY = 10 ms; plus some extra */
msleep(10 + 40);
update_address(udev, 0);
if (hcd->driver->reset_device) {
status = hcd->driver->reset_device(hcd, udev);
if (status < 0) {
dev_err(&udev->dev, "Cannot reset "
"HCD device state\n");
break;
}
}
/* FALL THROUGH */
case -ENOTCONN:
case -ENODEV:
clear_port_feature(hub->hdev,
port1, USB_PORT_FEAT_C_RESET);
/* FIXME need disconnect() for NOTATTACHED device */
usb_set_device_state(udev, status
? USB_STATE_NOTATTACHED
: USB_STATE_DEFAULT);
goto done;
}
dev_dbg (hub->intfdev,
"port %d not enabled, trying reset again...\n",
port1);
delay = HUB_LONG_RESET_TIME;
}
dev_err (hub->intfdev,
"Cannot enable port %i. Maybe the USB cable is bad?\n",
port1);
done:
up_read(&ehci_cf_port_reset_rwsem);
return status;
}
#ifdef CONFIG_PM
#define MASK_BITS (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION | \
USB_PORT_STAT_SUSPEND)
#define WANT_BITS (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION)
/* Determine whether the device on a port is ready for a normal resume,
* is ready for a reset-resume, or should be disconnected.
*/
static int check_port_resume_type(struct usb_device *udev,
struct usb_hub *hub, int port1,
int status, unsigned portchange, unsigned portstatus)
{
/* Is the device still present? */
if (status || (portstatus & MASK_BITS) != WANT_BITS) {
if (status >= 0)
status = -ENODEV;
}
/* Can't do a normal resume if the port isn't enabled,
* so try a reset-resume instead.
*/
else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
if (udev->persist_enabled)
udev->reset_resume = 1;
else
status = -ENODEV;
}
if (status) {
dev_dbg(hub->intfdev,
"port %d status %04x.%04x after resume, %d\n",
port1, portchange, portstatus, status);
} else if (udev->reset_resume) {
/* Late port handoff can set status-change bits */
if (portchange & USB_PORT_STAT_C_CONNECTION)
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_CONNECTION);
if (portchange & USB_PORT_STAT_C_ENABLE)
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_ENABLE);
}
return status;
}
#ifdef CONFIG_USB_SUSPEND
/*
* usb_port_suspend - suspend a usb device's upstream port
* @udev: device that's no longer in active use, not a root hub
* Context: must be able to sleep; device not locked; pm locks held
*
* Suspends a USB device that isn't in active use, conserving power.
* Devices may wake out of a suspend, if anything important happens,
* using the remote wakeup mechanism. They may also be taken out of
* suspend by the host, using usb_port_resume(). It's also routine
* to disconnect devices while they are suspended.
*
* This only affects the USB hardware for a device; its interfaces
* (and, for hubs, child devices) must already have been suspended.
*
* Selective port suspend reduces power; most suspended devices draw
* less than 500 uA. It's also used in OTG, along with remote wakeup.
* All devices below the suspended port are also suspended.
*
* Devices leave suspend state when the host wakes them up. Some devices
* also support "remote wakeup", where the device can activate the USB
* tree above them to deliver data, such as a keypress or packet. In
* some cases, this wakes the USB host.
*
* Suspending OTG devices may trigger HNP, if that's been enabled
* between a pair of dual-role devices. That will change roles, such
* as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
*
* Devices on USB hub ports have only one "suspend" state, corresponding
* to ACPI D2, "may cause the device to lose some context".
* State transitions include:
*
* - suspend, resume ... when the VBUS power link stays live
* - suspend, disconnect ... VBUS lost
*
* Once VBUS drop breaks the circuit, the port it's using has to go through
* normal re-enumeration procedures, starting with enabling VBUS power.
* Other than re-initializing the hub (plug/unplug, except for root hubs),
* Linux (2.6) currently has NO mechanisms to initiate that: no khubd
* timer, no SRP, no requests through sysfs.
*
* If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
* the root hub for their bus goes into global suspend ... so we don't
* (falsely) update the device power state to say it suspended.
*
* Returns 0 on success, else negative errno.
*/
int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
{
struct usb_hub *hub = hdev_to_hub(udev->parent);
int port1 = udev->portnum;
int status;
// dev_dbg(hub->intfdev, "suspend port %d\n", port1);
/* enable remote wakeup when appropriate; this lets the device
* wake up the upstream hub (including maybe the root hub).
*
* NOTE: OTG devices may issue remote wakeup (or SRP) even when
* we don't explicitly enable it here.
*/
if (udev->do_remote_wakeup) {
status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
USB_DEVICE_REMOTE_WAKEUP, 0,
NULL, 0,
USB_CTRL_SET_TIMEOUT);
if (status) {
dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
status);
/* bail if autosuspend is requested */
if (msg.event & PM_EVENT_AUTO)
return status;
}
}
/* see 7.1.7.6 */
status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
if (status) {
dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
port1, status);
/* paranoia: "should not happen" */
if (udev->do_remote_wakeup)
(void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
USB_DEVICE_REMOTE_WAKEUP, 0,
NULL, 0,
USB_CTRL_SET_TIMEOUT);
} else {
/* device has up to 10 msec to fully suspend */
dev_dbg(&udev->dev, "usb %ssuspend\n",
(msg.event & PM_EVENT_AUTO ? "auto-" : ""));
usb_set_device_state(udev, USB_STATE_SUSPENDED);
msleep(10);
}
usb_mark_last_busy(hub->hdev);
return status;
}
/*
* If the USB "suspend" state is in use (rather than "global suspend"),
* many devices will be individually taken out of suspend state using
* special "resume" signaling. This routine kicks in shortly after
* hardware resume signaling is finished, either because of selective
* resume (by host) or remote wakeup (by device) ... now see what changed
* in the tree that's rooted at this device.
*
* If @udev->reset_resume is set then the device is reset before the
* status check is done.
*/
static int finish_port_resume(struct usb_device *udev)
{
int status = 0;
u16 devstatus;
/* caller owns the udev device lock */
dev_dbg(&udev->dev, "%s\n",
udev->reset_resume ? "finish reset-resume" : "finish resume");
/* usb ch9 identifies four variants of SUSPENDED, based on what
* state the device resumes to. Linux currently won't see the
* first two on the host side; they'd be inside hub_port_init()
* during many timeouts, but khubd can't suspend until later.
*/
usb_set_device_state(udev, udev->actconfig
? USB_STATE_CONFIGURED
: USB_STATE_ADDRESS);
/* 10.5.4.5 says not to reset a suspended port if the attached
* device is enabled for remote wakeup. Hence the reset
* operation is carried out here, after the port has been
* resumed.
*/
if (udev->reset_resume)
retry_reset_resume:
status = usb_reset_and_verify_device(udev);
/* 10.5.4.5 says be sure devices in the tree are still there.
* For now let's assume the device didn't go crazy on resume,
* and device drivers will know about any resume quirks.
*/
if (status == 0) {
devstatus = 0;
status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
if (status >= 0)
status = (status > 0 ? 0 : -ENODEV);
/* If a normal resume failed, try doing a reset-resume */
if (status && !udev->reset_resume && udev->persist_enabled) {
dev_dbg(&udev->dev, "retry with reset-resume\n");
udev->reset_resume = 1;
goto retry_reset_resume;
}
}
if (status) {
dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
status);
} else if (udev->actconfig) {
le16_to_cpus(&devstatus);
if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
status = usb_control_msg(udev,
usb_sndctrlpipe(udev, 0),
USB_REQ_CLEAR_FEATURE,
USB_RECIP_DEVICE,
USB_DEVICE_REMOTE_WAKEUP, 0,
NULL, 0,
USB_CTRL_SET_TIMEOUT);
if (status)
dev_dbg(&udev->dev,
"disable remote wakeup, status %d\n",
status);
}
status = 0;
}
return status;
}
/*
* usb_port_resume - re-activate a suspended usb device's upstream port
* @udev: device to re-activate, not a root hub
* Context: must be able to sleep; device not locked; pm locks held
*
* This will re-activate the suspended device, increasing power usage
* while letting drivers communicate again with its endpoints.
* USB resume explicitly guarantees that the power session between
* the host and the device is the same as it was when the device
* suspended.
*
* If @udev->reset_resume is set then this routine won't check that the
* port is still enabled. Furthermore, finish_port_resume() above will
* reset @udev. The end result is that a broken power session can be
* recovered and @udev will appear to persist across a loss of VBUS power.
*
* For example, if a host controller doesn't maintain VBUS suspend current
* during a system sleep or is reset when the system wakes up, all the USB
* power sessions below it will be broken. This is especially troublesome
* for mass-storage devices containing mounted filesystems, since the
* device will appear to have disconnected and all the memory mappings
* to it will be lost. Using the USB_PERSIST facility, the device can be
* made to appear as if it had not disconnected.
*
* This facility can be dangerous. Although usb_reset_and_verify_device() makes
* every effort to insure that the same device is present after the
* reset as before, it cannot provide a 100% guarantee. Furthermore it's
* quite possible for a device to remain unaltered but its media to be
* changed. If the user replaces a flash memory card while the system is
* asleep, he will have only himself to blame when the filesystem on the
* new card is corrupted and the system crashes.
*
* Returns 0 on success, else negative errno.
*/
int usb_port_resume(struct usb_device *udev, pm_message_t msg)
{
struct usb_hub *hub = hdev_to_hub(udev->parent);
int port1 = udev->portnum;
int status;
u16 portchange, portstatus;
/* Skip the initial Clear-Suspend step for a remote wakeup */
status = hub_port_status(hub, port1, &portstatus, &portchange);
if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND))
goto SuspendCleared;
// dev_dbg(hub->intfdev, "resume port %d\n", port1);
set_bit(port1, hub->busy_bits);
/* see 7.1.7.7; affects power usage, but not budgeting */
status = clear_port_feature(hub->hdev,
port1, USB_PORT_FEAT_SUSPEND);
if (status) {
dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
port1, status);
} else {
/* drive resume for at least 20 msec */
dev_dbg(&udev->dev, "usb %sresume\n",
(msg.event & PM_EVENT_AUTO ? "auto-" : ""));
msleep(25);
/* Virtual root hubs can trigger on GET_PORT_STATUS to
* stop resume signaling. Then finish the resume
* sequence.
*/
status = hub_port_status(hub, port1, &portstatus, &portchange);
/* TRSMRCY = 10 msec */
msleep(10);
}
SuspendCleared:
if (status == 0) {
if (portchange & USB_PORT_STAT_C_SUSPEND)
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_SUSPEND);
}
clear_bit(port1, hub->busy_bits);
status = check_port_resume_type(udev,
hub, port1, status, portchange, portstatus);
if (status == 0)
status = finish_port_resume(udev);
if (status < 0) {
dev_dbg(&udev->dev, "can't resume, status %d\n", status);
hub_port_logical_disconnect(hub, port1);
}
return status;
}
/* caller has locked udev */
int usb_remote_wakeup(struct usb_device *udev)
{
int status = 0;
if (udev->state == USB_STATE_SUSPENDED) {
dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
status = usb_autoresume_device(udev);
if (status == 0) {
/* Let the drivers do their thing, then... */
usb_autosuspend_device(udev);
}
}
return status;
}
#else /* CONFIG_USB_SUSPEND */
/* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */
int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
{
return 0;
}
/* However we may need to do a reset-resume */
int usb_port_resume(struct usb_device *udev, pm_message_t msg)
{
struct usb_hub *hub = hdev_to_hub(udev->parent);
int port1 = udev->portnum;
int status;
u16 portchange, portstatus;
status = hub_port_status(hub, port1, &portstatus, &portchange);
status = check_port_resume_type(udev,
hub, port1, status, portchange, portstatus);
if (status) {
dev_dbg(&udev->dev, "can't resume, status %d\n", status);
hub_port_logical_disconnect(hub, port1);
} else if (udev->reset_resume) {
dev_dbg(&udev->dev, "reset-resume\n");
status = usb_reset_and_verify_device(udev);
}
return status;
}
#endif
static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
{
struct usb_hub *hub = usb_get_intfdata (intf);
struct usb_device *hdev = hub->hdev;
unsigned port1;
/* fail if children aren't already suspended */
for (port1 = 1; port1 <= hdev->maxchild; port1++) {
struct usb_device *udev;
udev = hdev->children [port1-1];
if (udev && udev->can_submit) {
if (!(msg.event & PM_EVENT_AUTO))
dev_dbg(&intf->dev, "port %d nyet suspended\n",
port1);
return -EBUSY;
}
}
dev_dbg(&intf->dev, "%s\n", __func__);
/* stop khubd and related activity */
hub_quiesce(hub, HUB_SUSPEND);
return 0;
}
static int hub_resume(struct usb_interface *intf)
{
struct usb_hub *hub = usb_get_intfdata(intf);
dev_dbg(&intf->dev, "%s\n", __func__);
hub_activate(hub, HUB_RESUME);
return 0;
}
static int hub_reset_resume(struct usb_interface *intf)
{
struct usb_hub *hub = usb_get_intfdata(intf);
dev_dbg(&intf->dev, "%s\n", __func__);
hub_activate(hub, HUB_RESET_RESUME);
return 0;
}
/**
* usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
* @rhdev: struct usb_device for the root hub
*
* The USB host controller driver calls this function when its root hub
* is resumed and Vbus power has been interrupted or the controller
* has been reset. The routine marks @rhdev as having lost power.
* When the hub driver is resumed it will take notice and carry out
* power-session recovery for all the "USB-PERSIST"-enabled child devices;
* the others will be disconnected.
*/
void usb_root_hub_lost_power(struct usb_device *rhdev)
{
dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
rhdev->reset_resume = 1;
}
EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
#else /* CONFIG_PM */
#define hub_suspend NULL
#define hub_resume NULL
#define hub_reset_resume NULL
#endif
/* USB 2.0 spec, 7.1.7.3 / fig 7-29:
*
* Between connect detection and reset signaling there must be a delay
* of 100ms at least for debounce and power-settling. The corresponding
* timer shall restart whenever the downstream port detects a disconnect.
*
* Apparently there are some bluetooth and irda-dongles and a number of
* low-speed devices for which this debounce period may last over a second.
* Not covered by the spec - but easy to deal with.
*
* This implementation uses a 1500ms total debounce timeout; if the
* connection isn't stable by then it returns -ETIMEDOUT. It checks
* every 25ms for transient disconnects. When the port status has been
* unchanged for 100ms it returns the port status.
*/
static int hub_port_debounce(struct usb_hub *hub, int port1)
{
int ret;
int total_time, stable_time = 0;
u16 portchange, portstatus;
unsigned connection = 0xffff;
for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
ret = hub_port_status(hub, port1, &portstatus, &portchange);
if (ret < 0)
return ret;
if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
(portstatus & USB_PORT_STAT_CONNECTION) == connection) {
stable_time += HUB_DEBOUNCE_STEP;
if (stable_time >= HUB_DEBOUNCE_STABLE)
break;
} else {
stable_time = 0;
connection = portstatus & USB_PORT_STAT_CONNECTION;
}
if (portchange & USB_PORT_STAT_C_CONNECTION) {
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_CONNECTION);
}
if (total_time >= HUB_DEBOUNCE_TIMEOUT)
break;
msleep(HUB_DEBOUNCE_STEP);
}
dev_dbg (hub->intfdev,
"debounce: port %d: total %dms stable %dms status 0x%x\n",
port1, total_time, stable_time, portstatus);
if (stable_time < HUB_DEBOUNCE_STABLE)
return -ETIMEDOUT;
return portstatus;
}
void usb_ep0_reinit(struct usb_device *udev)
{
usb_disable_endpoint(udev, 0 + USB_DIR_IN, true);
usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true);
usb_enable_endpoint(udev, &udev->ep0, true);
}
EXPORT_SYMBOL_GPL(usb_ep0_reinit);
#define usb_sndaddr0pipe() (PIPE_CONTROL << 30)
#define usb_rcvaddr0pipe() ((PIPE_CONTROL << 30) | USB_DIR_IN)
static int hub_set_address(struct usb_device *udev, int devnum)
{
int retval;
struct usb_hcd *hcd = bus_to_hcd(udev->bus);
/*
* The host controller will choose the device address,
* instead of the core having chosen it earlier
*/
if (!hcd->driver->address_device && devnum <= 1)
return -EINVAL;
if (udev->state == USB_STATE_ADDRESS)
return 0;
if (udev->state != USB_STATE_DEFAULT)
return -EINVAL;
if (hcd->driver->address_device)
retval = hcd->driver->address_device(hcd, udev);
else
retval = usb_control_msg(udev, usb_sndaddr0pipe(),
USB_REQ_SET_ADDRESS, 0, devnum, 0,
NULL, 0, USB_CTRL_SET_TIMEOUT);
if (retval == 0) {
update_address(udev, devnum);
/* Device now using proper address. */
usb_set_device_state(udev, USB_STATE_ADDRESS);
usb_ep0_reinit(udev);
}
return retval;
}
/* Reset device, (re)assign address, get device descriptor.
* Device connection must be stable, no more debouncing needed.
* Returns device in USB_STATE_ADDRESS, except on error.
*
* If this is called for an already-existing device (as part of
* usb_reset_and_verify_device), the caller must own the device lock. For a
* newly detected device that is not accessible through any global
* pointers, it's not necessary to lock the device.
*/
static int
hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
int retry_counter)
{
static DEFINE_MUTEX(usb_address0_mutex);
struct usb_device *hdev = hub->hdev;
struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
int i, j, retval;
unsigned delay = HUB_SHORT_RESET_TIME;
enum usb_device_speed oldspeed = udev->speed;
char *speed, *type;
int devnum = udev->devnum;
/* root hub ports have a slightly longer reset period
* (from USB 2.0 spec, section 7.1.7.5)
*/
if (!hdev->parent) {
delay = HUB_ROOT_RESET_TIME;
if (port1 == hdev->bus->otg_port)
hdev->bus->b_hnp_enable = 0;
}
/* Some low speed devices have problems with the quick delay, so */
/* be a bit pessimistic with those devices. RHbug #23670 */
if (oldspeed == USB_SPEED_LOW)
delay = HUB_LONG_RESET_TIME;
mutex_lock(&usb_address0_mutex);
if (!udev->config && oldspeed == USB_SPEED_SUPER) {
/* Don't reset USB 3.0 devices during an initial setup */
usb_set_device_state(udev, USB_STATE_DEFAULT);
} else {
/* Reset the device; full speed may morph to high speed */
/* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
retval = hub_port_reset(hub, port1, udev, delay);
if (retval < 0) /* error or disconnect */
goto fail;
/* success, speed is known */
}
retval = -ENODEV;
if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
dev_dbg(&udev->dev, "device reset changed speed!\n");
goto fail;
}
oldspeed = udev->speed;
/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
* it's fixed size except for full speed devices.
* For Wireless USB devices, ep0 max packet is always 512 (tho
* reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
*/
switch (udev->speed) {
case USB_SPEED_SUPER:
case USB_SPEED_WIRELESS: /* fixed at 512 */
udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
break;
case USB_SPEED_HIGH: /* fixed at 64 */
udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
break;
case USB_SPEED_FULL: /* 8, 16, 32, or 64 */
/* to determine the ep0 maxpacket size, try to read
* the device descriptor to get bMaxPacketSize0 and
* then correct our initial guess.
*/
udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
break;
case USB_SPEED_LOW: /* fixed at 8 */
udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8);
break;
default:
goto fail;
}
type = "";
switch (udev->speed) {
case USB_SPEED_LOW: speed = "low"; break;
case USB_SPEED_FULL: speed = "full"; break;
case USB_SPEED_HIGH: speed = "high"; break;
case USB_SPEED_SUPER:
speed = "super";
break;
case USB_SPEED_WIRELESS:
speed = "variable";
type = "Wireless ";
break;
default: speed = "?"; break;
}
if (udev->speed != USB_SPEED_SUPER)
dev_info(&udev->dev,
"%s %s speed %sUSB device using %s and address %d\n",
(udev->config) ? "reset" : "new", speed, type,
udev->bus->controller->driver->name, devnum);
/* Set up TT records, if needed */
if (hdev->tt) {
udev->tt = hdev->tt;
udev->ttport = hdev->ttport;
} else if (udev->speed != USB_SPEED_HIGH
&& hdev->speed == USB_SPEED_HIGH) {
udev->tt = &hub->tt;
udev->ttport = port1;
}
/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
* Because device hardware and firmware is sometimes buggy in
* this area, and this is how Linux has done it for ages.
* Change it cautiously.
*
* NOTE: If USE_NEW_SCHEME() is true we will start by issuing
* a 64-byte GET_DESCRIPTOR request. This is what Windows does,
* so it may help with some non-standards-compliant devices.
* Otherwise we start with SET_ADDRESS and then try to read the
* first 8 bytes of the device descriptor to get the ep0 maxpacket
* value.
*/
for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
/*
* An xHCI controller cannot send any packets to a device until
* a set address command successfully completes.
*/
if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3)) {
struct usb_device_descriptor *buf;
int r = 0;
#define GET_DESCRIPTOR_BUFSIZE 64
buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
if (!buf) {
retval = -ENOMEM;
continue;
}
/* Retry on all errors; some devices are flakey.
* 255 is for WUSB devices, we actually need to use
* 512 (WUSB1.0[4.8.1]).
*/
for (j = 0; j < 3; ++j) {
buf->bMaxPacketSize0 = 0;
r = usb_control_msg(udev, usb_rcvaddr0pipe(),
USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
USB_DT_DEVICE << 8, 0,
buf, GET_DESCRIPTOR_BUFSIZE,
initial_descriptor_timeout);
switch (buf->bMaxPacketSize0) {
case 8: case 16: case 32: case 64: case 255:
if (buf->bDescriptorType ==
USB_DT_DEVICE) {
r = 0;
break;
}
/* FALL THROUGH */
default:
if (r == 0)
r = -EPROTO;
break;
}
if (r == 0)
break;
}
udev->descriptor.bMaxPacketSize0 =
buf->bMaxPacketSize0;
kfree(buf);
retval = hub_port_reset(hub, port1, udev, delay);
if (retval < 0) /* error or disconnect */
goto fail;
if (oldspeed != udev->speed) {
dev_dbg(&udev->dev,
"device reset changed speed!\n");
retval = -ENODEV;
goto fail;
}
if (r) {
dev_err(&udev->dev,
"device descriptor read/64, error %d\n",
r);
retval = -EMSGSIZE;
continue;
}
#undef GET_DESCRIPTOR_BUFSIZE
}
/*
* If device is WUSB, we already assigned an
* unauthorized address in the Connect Ack sequence;
* authorization will assign the final address.
*/
if (udev->wusb == 0) {
for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
retval = hub_set_address(udev, devnum);
if (retval >= 0)
break;
msleep(200);
}
if (retval < 0) {
dev_err(&udev->dev,
"device not accepting address %d, error %d\n",
devnum, retval);
goto fail;
}
if (udev->speed == USB_SPEED_SUPER) {
devnum = udev->devnum;
dev_info(&udev->dev,
"%s SuperSpeed USB device using %s and address %d\n",
(udev->config) ? "reset" : "new",
udev->bus->controller->driver->name, devnum);
}
/* cope with hardware quirkiness:
* - let SET_ADDRESS settle, some device hardware wants it
* - read ep0 maxpacket even for high and low speed,
*/
msleep(10);
if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3))
break;
}
retval = usb_get_device_descriptor(udev, 8);
if (retval < 8) {
dev_err(&udev->dev,
"device descriptor read/8, error %d\n",
retval);
if (retval >= 0)
retval = -EMSGSIZE;
} else {
retval = 0;
break;
}
}
if (retval)
goto fail;
if (udev->descriptor.bMaxPacketSize0 == 0xff ||
udev->speed == USB_SPEED_SUPER)
i = 512;
else
i = udev->descriptor.bMaxPacketSize0;
if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
if (udev->speed == USB_SPEED_LOW ||
!(i == 8 || i == 16 || i == 32 || i == 64)) {
dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", i);
retval = -EMSGSIZE;
goto fail;
}
if (udev->speed == USB_SPEED_FULL)
dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
else
dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
usb_ep0_reinit(udev);
}
retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
if (retval < (signed)sizeof(udev->descriptor)) {
dev_err(&udev->dev, "device descriptor read/all, error %d\n",
retval);
if (retval >= 0)
retval = -ENOMSG;
goto fail;
}
retval = 0;
/* notify HCD that we have a device connected and addressed */
if (hcd->driver->update_device)
hcd->driver->update_device(hcd, udev);
fail:
if (retval) {
hub_port_disable(hub, port1, 0);
update_address(udev, devnum); /* for disconnect processing */
}
mutex_unlock(&usb_address0_mutex);
return retval;
}
static void
check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
{
struct usb_qualifier_descriptor *qual;
int status;
qual = kmalloc (sizeof *qual, GFP_KERNEL);
if (qual == NULL)
return;
status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
qual, sizeof *qual);
if (status == sizeof *qual) {
dev_info(&udev->dev, "not running at top speed; "
"connect to a high speed hub\n");
/* hub LEDs are probably harder to miss than syslog */
if (hub->has_indicators) {
hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
schedule_delayed_work (&hub->leds, 0);
}
}
kfree(qual);
}
static unsigned
hub_power_remaining (struct usb_hub *hub)
{
struct usb_device *hdev = hub->hdev;
int remaining;
int port1;
if (!hub->limited_power)
return 0;
remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
struct usb_device *udev = hdev->children[port1 - 1];
int delta;
if (!udev)
continue;
/* Unconfigured devices may not use more than 100mA,
* or 8mA for OTG ports */
if (udev->actconfig)
delta = udev->actconfig->desc.bMaxPower * 2;
else if (port1 != udev->bus->otg_port || hdev->parent)
delta = 100;
else
delta = 8;
if (delta > hub->mA_per_port)
dev_warn(&udev->dev,
"%dmA is over %umA budget for port %d!\n",
delta, hub->mA_per_port, port1);
remaining -= delta;
}
if (remaining < 0) {
dev_warn(hub->intfdev, "%dmA over power budget!\n",
- remaining);
remaining = 0;
}
return remaining;
}
/* Handle physical or logical connection change events.
* This routine is called when:
* a port connection-change occurs;
* a port enable-change occurs (often caused by EMI);
* usb_reset_and_verify_device() encounters changed descriptors (as from
* a firmware download)
* caller already locked the hub
*/
static void hub_port_connect_change(struct usb_hub *hub, int port1,
u16 portstatus, u16 portchange)
{
struct usb_device *hdev = hub->hdev;
struct device *hub_dev = hub->intfdev;
struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
unsigned wHubCharacteristics =
le16_to_cpu(hub->descriptor->wHubCharacteristics);
struct usb_device *udev;
int status, i;
dev_dbg (hub_dev,
"port %d, status %04x, change %04x, %s\n",
port1, portstatus, portchange, portspeed (portstatus));
if (hub->has_indicators) {
set_port_led(hub, port1, HUB_LED_AUTO);
hub->indicator[port1-1] = INDICATOR_AUTO;
}
#ifdef CONFIG_USB_OTG
/* during HNP, don't repeat the debounce */
if (hdev->bus->is_b_host)
portchange &= ~(USB_PORT_STAT_C_CONNECTION |
USB_PORT_STAT_C_ENABLE);
#endif
/* Try to resuscitate an existing device */
udev = hdev->children[port1-1];
if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
udev->state != USB_STATE_NOTATTACHED) {
usb_lock_device(udev);
if (portstatus & USB_PORT_STAT_ENABLE) {
status = 0; /* Nothing to do */
#ifdef CONFIG_USB_SUSPEND
} else if (udev->state == USB_STATE_SUSPENDED &&
udev->persist_enabled) {
/* For a suspended device, treat this as a
* remote wakeup event.
*/
status = usb_remote_wakeup(udev);
#endif
} else {
status = -ENODEV; /* Don't resuscitate */
}
usb_unlock_device(udev);
if (status == 0) {
clear_bit(port1, hub->change_bits);
return;
}
}
/* Disconnect any existing devices under this port */
if (udev)
usb_disconnect(&hdev->children[port1-1]);
clear_bit(port1, hub->change_bits);
/* 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 (portchange & (USB_PORT_STAT_C_CONNECTION |
USB_PORT_STAT_C_ENABLE)) {
status = hub_port_debounce(hub, port1);
if (status < 0) {
if (printk_ratelimit())
dev_err(hub_dev, "connect-debounce failed, "
"port %d disabled\n", port1);
portstatus &= ~USB_PORT_STAT_CONNECTION;
} else {
portstatus = status;
}
}
/* Return now if debouncing failed or nothing is connected or
* the device was "removed".
*/
if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
test_bit(port1, hub->removed_bits)) {
/* maybe switch power back on (e.g. root hub was reset) */
if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
&& !(portstatus & USB_PORT_STAT_POWER))
set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
if (portstatus & USB_PORT_STAT_ENABLE)
goto done;
return;
}
for (i = 0; i < SET_CONFIG_TRIES; i++) {
/* reallocate for each attempt, since references
* to the previous one can escape in various ways
*/
udev = usb_alloc_dev(hdev, hdev->bus, port1);
if (!udev) {
dev_err (hub_dev,
"couldn't allocate port %d usb_device\n",
port1);
goto done;
}
usb_set_device_state(udev, USB_STATE_POWERED);
udev->bus_mA = hub->mA_per_port;
udev->level = hdev->level + 1;
udev->wusb = hub_is_wusb(hub);
/*
* USB 3.0 devices are reset automatically before the connect
* port status change appears, and the root hub port status
* shows the correct speed. We also get port change
* notifications for USB 3.0 devices from the USB 3.0 portion of
* an external USB 3.0 hub, but this isn't handled correctly yet
* FIXME.
*/
if (!(hcd->driver->flags & HCD_USB3))
udev->speed = USB_SPEED_UNKNOWN;
else if ((hdev->parent == NULL) &&
(portstatus & USB_PORT_STAT_SUPER_SPEED))
udev->speed = USB_SPEED_SUPER;
else
udev->speed = USB_SPEED_UNKNOWN;
/*
* Set the address.
* Note xHCI needs to issue an address device command later
* in the hub_port_init sequence for SS/HS/FS/LS devices,
* and xHC will assign an address to the device. But use
* kernel assigned address here, to avoid any address conflict
* issue.
*/
choose_address(udev);
if (udev->devnum <= 0) {
status = -ENOTCONN; /* Don't retry */
goto loop;
}
/* reset (non-USB 3.0 devices) and get descriptor */
status = hub_port_init(hub, udev, port1, i);
if (status < 0)
goto loop;
usb_detect_quirks(udev);
if (udev->quirks & USB_QUIRK_DELAY_INIT)
msleep(1000);
/* consecutive bus-powered hubs aren't reliable; they can
* violate the voltage drop budget. if the new child has
* a "powered" LED, users should notice we didn't enable it
* (without reading syslog), even without per-port LEDs
* on the parent.
*/
if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
&& udev->bus_mA <= 100) {
u16 devstat;
status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
&devstat);
if (status < 2) {
dev_dbg(&udev->dev, "get status %d ?\n", status);
goto loop_disable;
}
le16_to_cpus(&devstat);
if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
dev_err(&udev->dev,
"can't connect bus-powered hub "
"to this port\n");
if (hub->has_indicators) {
hub->indicator[port1-1] =
INDICATOR_AMBER_BLINK;
schedule_delayed_work (&hub->leds, 0);
}
status = -ENOTCONN; /* Don't retry */
goto loop_disable;
}
}
/* check for devices running slower than they could */
if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
&& udev->speed == USB_SPEED_FULL
&& highspeed_hubs != 0)
check_highspeed (hub, udev, port1);
/* Store the parent's children[] pointer. At this point
* udev becomes globally accessible, although presumably
* no one will look at it until hdev is unlocked.
*/
status = 0;
/* We mustn't add new devices if the parent hub has
* been disconnected; we would race with the
* recursively_mark_NOTATTACHED() routine.
*/
spin_lock_irq(&device_state_lock);
if (hdev->state == USB_STATE_NOTATTACHED)
status = -ENOTCONN;
else
hdev->children[port1-1] = udev;
spin_unlock_irq(&device_state_lock);
/* Run it through the hoops (find a driver, etc) */
if (!status) {
status = usb_new_device(udev);
if (status) {
spin_lock_irq(&device_state_lock);
hdev->children[port1-1] = NULL;
spin_unlock_irq(&device_state_lock);
}
}
if (status)
goto loop_disable;
status = hub_power_remaining(hub);
if (status)
dev_dbg(hub_dev, "%dmA power budget left\n", status);
return;
loop_disable:
hub_port_disable(hub, port1, 1);
loop:
usb_ep0_reinit(udev);
release_address(udev);
hub_free_dev(udev);
usb_put_dev(udev);
if ((status == -ENOTCONN) || (status == -ENOTSUPP))
break;
}
if (hub->hdev->parent ||
!hcd->driver->port_handed_over ||
!(hcd->driver->port_handed_over)(hcd, port1))
dev_err(hub_dev, "unable to enumerate USB device on port %d\n",
port1);
done:
hub_port_disable(hub, port1, 1);
if (hcd->driver->relinquish_port && !hub->hdev->parent)
hcd->driver->relinquish_port(hcd, port1);
}
static void hub_events(void)
{
struct list_head *tmp;
struct usb_device *hdev;
struct usb_interface *intf;
struct usb_hub *hub;
struct device *hub_dev;
u16 hubstatus;
u16 hubchange;
u16 portstatus;
u16 portchange;
int i, ret;
int connect_change;
/*
* We restart the list every time to avoid a deadlock with
* deleting hubs downstream from this one. This should be
* safe since we delete the hub from the event list.
* Not the most efficient, but avoids deadlocks.
*/
while (1) {
/* Grab the first entry at the beginning of the list */
spin_lock_irq(&hub_event_lock);
if (list_empty(&hub_event_list)) {
spin_unlock_irq(&hub_event_lock);
break;
}
tmp = hub_event_list.next;
list_del_init(tmp);
hub = list_entry(tmp, struct usb_hub, event_list);
kref_get(&hub->kref);
spin_unlock_irq(&hub_event_lock);
hdev = hub->hdev;
hub_dev = hub->intfdev;
intf = to_usb_interface(hub_dev);
dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
hdev->state, hub->descriptor
? hub->descriptor->bNbrPorts
: 0,
/* NOTE: expects max 15 ports... */
(u16) hub->change_bits[0],
(u16) hub->event_bits[0]);
/* Lock the device, then check to see if we were
* disconnected while waiting for the lock to succeed. */
usb_lock_device(hdev);
if (unlikely(hub->disconnected))
goto loop_disconnected;
/* If the hub has died, clean up after it */
if (hdev->state == USB_STATE_NOTATTACHED) {
hub->error = -ENODEV;
hub_quiesce(hub, HUB_DISCONNECT);
goto loop;
}
/* Autoresume */
ret = usb_autopm_get_interface(intf);
if (ret) {
dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
goto loop;
}
/* If this is an inactive hub, do nothing */
if (hub->quiescing)
goto loop_autopm;
if (hub->error) {
dev_dbg (hub_dev, "resetting for error %d\n",
hub->error);
ret = usb_reset_device(hdev);
if (ret) {
dev_dbg (hub_dev,
"error resetting hub: %d\n", ret);
goto loop_autopm;
}
hub->nerrors = 0;
hub->error = 0;
}
/* deal with port status changes */
for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
if (test_bit(i, hub->busy_bits))
continue;
connect_change = test_bit(i, hub->change_bits);
if (!test_and_clear_bit(i, hub->event_bits) &&
!connect_change)
continue;
ret = hub_port_status(hub, i,
&portstatus, &portchange);
if (ret < 0)
continue;
if (portchange & USB_PORT_STAT_C_CONNECTION) {
clear_port_feature(hdev, i,
USB_PORT_FEAT_C_CONNECTION);
connect_change = 1;
}
if (portchange & USB_PORT_STAT_C_ENABLE) {
if (!connect_change)
dev_dbg (hub_dev,
"port %d enable change, "
"status %08x\n",
i, portstatus);
clear_port_feature(hdev, i,
USB_PORT_FEAT_C_ENABLE);
/*
* EM interference sometimes causes badly
* shielded USB devices to be shutdown by
* the hub, this hack enables them again.
* Works at least with mouse driver.
*/
if (!(portstatus & USB_PORT_STAT_ENABLE)
&& !connect_change
&& hdev->children[i-1]) {
dev_err (hub_dev,
"port %i "
"disabled by hub (EMI?), "
"re-enabling...\n",
i);
connect_change = 1;
}
}
if (portchange & USB_PORT_STAT_C_SUSPEND) {
struct usb_device *udev;
clear_port_feature(hdev, i,
USB_PORT_FEAT_C_SUSPEND);
udev = hdev->children[i-1];
if (udev) {
/* TRSMRCY = 10 msec */
msleep(10);
usb_lock_device(udev);
ret = usb_remote_wakeup(hdev->
children[i-1]);
usb_unlock_device(udev);
if (ret < 0)
connect_change = 1;
} else {
ret = -ENODEV;
hub_port_disable(hub, i, 1);
}
dev_dbg (hub_dev,
"resume on port %d, status %d\n",
i, ret);
}
if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
dev_err (hub_dev,
"over-current change on port %d\n",
i);
clear_port_feature(hdev, i,
USB_PORT_FEAT_C_OVER_CURRENT);
hub_power_on(hub, true);
}
if (portchange & USB_PORT_STAT_C_RESET) {
dev_dbg (hub_dev,
"reset change on port %d\n",
i);
clear_port_feature(hdev, i,
USB_PORT_FEAT_C_RESET);
}
if (connect_change)
hub_port_connect_change(hub, i,
portstatus, portchange);
} /* end for i */
/* deal with hub status changes */
if (test_and_clear_bit(0, hub->event_bits) == 0)
; /* do nothing */
else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
dev_err (hub_dev, "get_hub_status failed\n");
else {
if (hubchange & HUB_CHANGE_LOCAL_POWER) {
dev_dbg (hub_dev, "power change\n");
clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
if (hubstatus & HUB_STATUS_LOCAL_POWER)
/* FIXME: Is this always true? */
hub->limited_power = 1;
else
hub->limited_power = 0;
}
if (hubchange & HUB_CHANGE_OVERCURRENT) {
dev_dbg (hub_dev, "overcurrent change\n");
msleep(500); /* Cool down */
clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
hub_power_on(hub, true);
}
}
loop_autopm:
/* Balance the usb_autopm_get_interface() above */
usb_autopm_put_interface_no_suspend(intf);
loop:
/* Balance the usb_autopm_get_interface_no_resume() in
* kick_khubd() and allow autosuspend.
*/
usb_autopm_put_interface(intf);
loop_disconnected:
usb_unlock_device(hdev);
kref_put(&hub->kref, hub_release);
} /* end while (1) */
}
static int hub_thread(void *__unused)
{
/* khubd needs to be freezable to avoid intefering with USB-PERSIST
* port handover. Otherwise it might see that a full-speed device
* was gone before the EHCI controller had handed its port over to
* the companion full-speed controller.
*/
set_freezable();
do {
hub_events();
wait_event_freezable(khubd_wait,
!list_empty(&hub_event_list) ||
kthread_should_stop());
} while (!kthread_should_stop() || !list_empty(&hub_event_list));
pr_debug("%s: khubd exiting\n", usbcore_name);
return 0;
}
static const struct usb_device_id hub_id_table[] = {
{ .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
.bDeviceClass = USB_CLASS_HUB},
{ .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
.bInterfaceClass = USB_CLASS_HUB},
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE (usb, hub_id_table);
static struct usb_driver hub_driver = {
.name = "hub",
.probe = hub_probe,
.disconnect = hub_disconnect,
.suspend = hub_suspend,
.resume = hub_resume,
.reset_resume = hub_reset_resume,
.pre_reset = hub_pre_reset,
.post_reset = hub_post_reset,
.unlocked_ioctl = hub_ioctl,
.id_table = hub_id_table,
.supports_autosuspend = 1,
};
int usb_hub_init(void)
{
if (usb_register(&hub_driver) < 0) {
printk(KERN_ERR "%s: can't register hub driver\n",
usbcore_name);
return -1;
}
khubd_task = kthread_run(hub_thread, NULL, "khubd");
if (!IS_ERR(khubd_task))
return 0;
/* Fall through if kernel_thread failed */
usb_deregister(&hub_driver);
printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
return -1;
}
void usb_hub_cleanup(void)
{
kthread_stop(khubd_task);
/*
* Hub resources are freed for us by usb_deregister. It calls
* usb_driver_purge on every device which in turn calls that
* devices disconnect function if it is using this driver.
* The hub_disconnect function takes care of releasing the
* individual hub resources. -greg
*/
usb_deregister(&hub_driver);
} /* usb_hub_cleanup() */
static int descriptors_changed(struct usb_device *udev,
struct usb_device_descriptor *old_device_descriptor)
{
int changed = 0;
unsigned index;
unsigned serial_len = 0;
unsigned len;
unsigned old_length;
int length;
char *buf;
if (memcmp(&udev->descriptor, old_device_descriptor,
sizeof(*old_device_descriptor)) != 0)
return 1;
/* Since the idVendor, idProduct, and bcdDevice values in the
* device descriptor haven't changed, we will assume the
* Manufacturer and Product strings haven't changed either.
* But the SerialNumber string could be different (e.g., a
* different flash card of the same brand).
*/
if (udev->serial)
serial_len = strlen(udev->serial) + 1;
len = serial_len;
for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
len = max(len, old_length);
}
buf = kmalloc(len, GFP_NOIO);
if (buf == NULL) {
dev_err(&udev->dev, "no mem to re-read configs after reset\n");
/* assume the worst */
return 1;
}
for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
old_length);
if (length != old_length) {
dev_dbg(&udev->dev, "config index %d, error %d\n",
index, length);
changed = 1;
break;
}
if (memcmp (buf, udev->rawdescriptors[index], old_length)
!= 0) {
dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
index,
((struct usb_config_descriptor *) buf)->
bConfigurationValue);
changed = 1;
break;
}
}
if (!changed && serial_len) {
length = usb_string(udev, udev->descriptor.iSerialNumber,
buf, serial_len);
if (length + 1 != serial_len) {
dev_dbg(&udev->dev, "serial string error %d\n",
length);
changed = 1;
} else if (memcmp(buf, udev->serial, length) != 0) {
dev_dbg(&udev->dev, "serial string changed\n");
changed = 1;
}
}
kfree(buf);
return changed;
}
/**
* usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
* @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
*
* WARNING - don't use this routine to reset a composite device
* (one with multiple interfaces owned by separate drivers)!
* Use usb_reset_device() instead.
*
* Do a port reset, reassign the device's address, and establish its
* former operating configuration. If the reset fails, or the device's
* descriptors change from their values before the reset, or the original
* configuration and altsettings cannot be restored, a flag will be set
* telling khubd to pretend the device has been disconnected and then
* re-connected. All drivers will be unbound, and the device will be
* re-enumerated and probed all over again.
*
* Returns 0 if the reset succeeded, -ENODEV if the device has been
* flagged for logical disconnection, or some other negative error code
* if the reset wasn't even attempted.
*
* The caller must own the device lock. For example, it's safe to use
* this from a driver probe() routine after downloading new firmware.
* For calls that might not occur during probe(), drivers should lock
* the device using usb_lock_device_for_reset().
*
* Locking exception: This routine may also be called from within an
* autoresume handler. Such usage won't conflict with other tasks
* holding the device lock because these tasks should always call
* usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
*/
static int usb_reset_and_verify_device(struct usb_device *udev)
{
struct usb_device *parent_hdev = udev->parent;
struct usb_hub *parent_hub;
struct usb_hcd *hcd = bus_to_hcd(udev->bus);
struct usb_device_descriptor descriptor = udev->descriptor;
int i, ret = 0;
int port1 = udev->portnum;
if (udev->state == USB_STATE_NOTATTACHED ||
udev->state == USB_STATE_SUSPENDED) {
dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
udev->state);
return -EINVAL;
}
if (!parent_hdev) {
/* this requires hcd-specific logic; see ohci_restart() */
dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
return -EISDIR;
}
parent_hub = hdev_to_hub(parent_hdev);
set_bit(port1, parent_hub->busy_bits);
for (i = 0; i < SET_CONFIG_TRIES; ++i) {
/* ep0 maxpacket size may change; let the HCD know about it.
* Other endpoints will be handled by re-enumeration. */
usb_ep0_reinit(udev);
ret = hub_port_init(parent_hub, udev, port1, i);
if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
break;
}
clear_bit(port1, parent_hub->busy_bits);
if (ret < 0)
goto re_enumerate;
/* Device might have changed firmware (DFU or similar) */
if (descriptors_changed(udev, &descriptor)) {
dev_info(&udev->dev, "device firmware changed\n");
udev->descriptor = descriptor; /* for disconnect() calls */
goto re_enumerate;
}
/* Restore the device's previous configuration */
if (!udev->actconfig)
goto done;
mutex_lock(&hcd->bandwidth_mutex);
ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL);
if (ret < 0) {
dev_warn(&udev->dev,
"Busted HC? Not enough HCD resources for "
"old configuration.\n");
mutex_unlock(&hcd->bandwidth_mutex);
goto re_enumerate;
}
ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
USB_REQ_SET_CONFIGURATION, 0,
udev->actconfig->desc.bConfigurationValue, 0,
NULL, 0, USB_CTRL_SET_TIMEOUT);
if (ret < 0) {
dev_err(&udev->dev,
"can't restore configuration #%d (error=%d)\n",
udev->actconfig->desc.bConfigurationValue, ret);
mutex_unlock(&hcd->bandwidth_mutex);
goto re_enumerate;
}
mutex_unlock(&hcd->bandwidth_mutex);
usb_set_device_state(udev, USB_STATE_CONFIGURED);
/* Put interfaces back into the same altsettings as before.
* Don't bother to send the Set-Interface request for interfaces
* that were already in altsetting 0; besides being unnecessary,
* many devices can't handle it. Instead just reset the host-side
* endpoint state.
*/
for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
struct usb_host_config *config = udev->actconfig;
struct usb_interface *intf = config->interface[i];
struct usb_interface_descriptor *desc;
desc = &intf->cur_altsetting->desc;
if (desc->bAlternateSetting == 0) {
usb_disable_interface(udev, intf, true);
usb_enable_interface(udev, intf, true);
ret = 0;
} else {
/* Let the bandwidth allocation function know that this
* device has been reset, and it will have to use
* alternate setting 0 as the current alternate setting.
*/
intf->resetting_device = 1;
ret = usb_set_interface(udev, desc->bInterfaceNumber,
desc->bAlternateSetting);
intf->resetting_device = 0;
}
if (ret < 0) {
dev_err(&udev->dev, "failed to restore interface %d "
"altsetting %d (error=%d)\n",
desc->bInterfaceNumber,
desc->bAlternateSetting,
ret);
goto re_enumerate;
}
}
done:
return 0;
re_enumerate:
hub_port_logical_disconnect(parent_hub, port1);
return -ENODEV;
}
/**
* usb_reset_device - warn interface drivers and perform a USB port reset
* @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
*
* Warns all drivers bound to registered interfaces (using their pre_reset
* method), performs the port reset, and then lets the drivers know that
* the reset is over (using their post_reset method).
*
* Return value is the same as for usb_reset_and_verify_device().
*
* The caller must own the device lock. For example, it's safe to use
* this from a driver probe() routine after downloading new firmware.
* For calls that might not occur during probe(), drivers should lock
* the device using usb_lock_device_for_reset().
*
* If an interface is currently being probed or disconnected, we assume
* its driver knows how to handle resets. For all other interfaces,
* if the driver doesn't have pre_reset and post_reset methods then
* we attempt to unbind it and rebind afterward.
*/
int usb_reset_device(struct usb_device *udev)
{
int ret;
int i;
struct usb_host_config *config = udev->actconfig;
if (udev->state == USB_STATE_NOTATTACHED ||
udev->state == USB_STATE_SUSPENDED) {
dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
udev->state);
return -EINVAL;
}
/* Prevent autosuspend during the reset */
usb_autoresume_device(udev);
if (config) {
for (i = 0; i < config->desc.bNumInterfaces; ++i) {
struct usb_interface *cintf = config->interface[i];
struct usb_driver *drv;
int unbind = 0;
if (cintf->dev.driver) {
drv = to_usb_driver(cintf->dev.driver);
if (drv->pre_reset && drv->post_reset)
unbind = (drv->pre_reset)(cintf);
else if (cintf->condition ==
USB_INTERFACE_BOUND)
unbind = 1;
if (unbind)
usb_forced_unbind_intf(cintf);
}
}
}
ret = usb_reset_and_verify_device(udev);
if (config) {
for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
struct usb_interface *cintf = config->interface[i];
struct usb_driver *drv;
int rebind = cintf->needs_binding;
if (!rebind && cintf->dev.driver) {
drv = to_usb_driver(cintf->dev.driver);
if (drv->post_reset)
rebind = (drv->post_reset)(cintf);
else if (cintf->condition ==
USB_INTERFACE_BOUND)
rebind = 1;
}
if (ret == 0 && rebind)
usb_rebind_intf(cintf);
}
}
usb_autosuspend_device(udev);
return ret;
}
EXPORT_SYMBOL_GPL(usb_reset_device);
/**
* usb_queue_reset_device - Reset a USB device from an atomic context
* @iface: USB interface belonging to the device to reset
*
* This function can be used to reset a USB device from an atomic
* context, where usb_reset_device() won't work (as it blocks).
*
* Doing a reset via this method is functionally equivalent to calling
* usb_reset_device(), except for the fact that it is delayed to a
* workqueue. This means that any drivers bound to other interfaces
* might be unbound, as well as users from usbfs in user space.
*
* Corner cases:
*
* - Scheduling two resets at the same time from two different drivers
* attached to two different interfaces of the same device is
* possible; depending on how the driver attached to each interface
* handles ->pre_reset(), the second reset might happen or not.
*
* - If a driver is unbound and it had a pending reset, the reset will
* be cancelled.
*
* - This function can be called during .probe() or .disconnect()
* times. On return from .disconnect(), any pending resets will be
* cancelled.
*
* There is no no need to lock/unlock the @reset_ws as schedule_work()
* does its own.
*
* NOTE: We don't do any reference count tracking because it is not
* needed. The lifecycle of the work_struct is tied to the
* usb_interface. Before destroying the interface we cancel the
* work_struct, so the fact that work_struct is queued and or
* running means the interface (and thus, the device) exist and
* are referenced.
*/
void usb_queue_reset_device(struct usb_interface *iface)
{
schedule_work(&iface->reset_ws);
}
EXPORT_SYMBOL_GPL(usb_queue_reset_device);
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