2 * drivers/usb/driver.c - most of the driver model stuff for usb
4 * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
6 * based on drivers/usb/usb.c which had the following copyrights:
7 * (C) Copyright Linus Torvalds 1999
8 * (C) Copyright Johannes Erdfelt 1999-2001
9 * (C) Copyright Andreas Gal 1999
10 * (C) Copyright Gregory P. Smith 1999
11 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
12 * (C) Copyright Randy Dunlap 2000
13 * (C) Copyright David Brownell 2000-2004
14 * (C) Copyright Yggdrasil Computing, Inc. 2000
15 * (usb_device_id matching changes by Adam J. Richter)
16 * (C) Copyright Greg Kroah-Hartman 2002-2003
18 * NOTE! This is not actually a driver at all, rather this is
19 * just a collection of helper routines that implement the
20 * matching, probing, releasing, suspending and resuming for
25 #include <linux/device.h>
26 #include <linux/usb.h>
27 #include <linux/usb/quirks.h>
28 #include <linux/workqueue.h>
36 * Adds a new dynamic USBdevice ID to this driver,
37 * and cause the driver to probe for all devices again.
39 ssize_t usb_store_new_id(struct usb_dynids *dynids,
40 struct device_driver *driver,
41 const char *buf, size_t count)
43 struct usb_dynid *dynid;
49 fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
53 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
57 INIT_LIST_HEAD(&dynid->node);
58 dynid->id.idVendor = idVendor;
59 dynid->id.idProduct = idProduct;
60 dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;
62 spin_lock(&dynids->lock);
63 list_add_tail(&dynid->node, &dynids->list);
64 spin_unlock(&dynids->lock);
66 if (get_driver(driver)) {
67 retval = driver_attach(driver);
75 EXPORT_SYMBOL_GPL(usb_store_new_id);
77 static ssize_t store_new_id(struct device_driver *driver,
78 const char *buf, size_t count)
80 struct usb_driver *usb_drv = to_usb_driver(driver);
82 return usb_store_new_id(&usb_drv->dynids, driver, buf, count);
84 static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);
86 static int usb_create_newid_file(struct usb_driver *usb_drv)
90 if (usb_drv->no_dynamic_id)
93 if (usb_drv->probe != NULL)
94 error = driver_create_file(&usb_drv->drvwrap.driver,
100 static void usb_remove_newid_file(struct usb_driver *usb_drv)
102 if (usb_drv->no_dynamic_id)
105 if (usb_drv->probe != NULL)
106 driver_remove_file(&usb_drv->drvwrap.driver,
107 &driver_attr_new_id);
110 static void usb_free_dynids(struct usb_driver *usb_drv)
112 struct usb_dynid *dynid, *n;
114 spin_lock(&usb_drv->dynids.lock);
115 list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
116 list_del(&dynid->node);
119 spin_unlock(&usb_drv->dynids.lock);
122 static inline int usb_create_newid_file(struct usb_driver *usb_drv)
127 static void usb_remove_newid_file(struct usb_driver *usb_drv)
131 static inline void usb_free_dynids(struct usb_driver *usb_drv)
136 static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
137 struct usb_driver *drv)
139 struct usb_dynid *dynid;
141 spin_lock(&drv->dynids.lock);
142 list_for_each_entry(dynid, &drv->dynids.list, node) {
143 if (usb_match_one_id(intf, &dynid->id)) {
144 spin_unlock(&drv->dynids.lock);
148 spin_unlock(&drv->dynids.lock);
153 /* called from driver core with dev locked */
154 static int usb_probe_device(struct device *dev)
156 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
157 struct usb_device *udev;
160 dev_dbg(dev, "%s\n", __func__);
162 if (!is_usb_device(dev)) /* Sanity check */
165 udev = to_usb_device(dev);
167 /* TODO: Add real matching code */
169 /* The device should always appear to be in use
170 * unless the driver suports autosuspend.
172 udev->pm_usage_cnt = !(udriver->supports_autosuspend);
174 error = udriver->probe(udev);
178 /* called from driver core with dev locked */
179 static int usb_unbind_device(struct device *dev)
181 struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
183 udriver->disconnect(to_usb_device(dev));
188 /* called from driver core with dev locked */
189 static int usb_probe_interface(struct device *dev)
191 struct usb_driver *driver = to_usb_driver(dev->driver);
192 struct usb_interface *intf;
193 struct usb_device *udev;
194 const struct usb_device_id *id;
197 dev_dbg(dev, "%s\n", __func__);
199 if (is_usb_device(dev)) /* Sanity check */
202 intf = to_usb_interface(dev);
203 udev = interface_to_usbdev(intf);
204 intf->needs_binding = 0;
206 if (udev->authorized == 0) {
207 dev_err(&intf->dev, "Device is not authorized for usage\n");
211 id = usb_match_id(intf, driver->id_table);
213 id = usb_match_dynamic_id(intf, driver);
215 dev_dbg(dev, "%s - got id\n", __func__);
217 error = usb_autoresume_device(udev);
221 /* Interface "power state" doesn't correspond to any hardware
222 * state whatsoever. We use it to record when it's bound to
223 * a driver that may start I/0: it's not frozen/quiesced.
226 intf->condition = USB_INTERFACE_BINDING;
228 /* The interface should always appear to be in use
229 * unless the driver suports autosuspend.
231 intf->pm_usage_cnt = !(driver->supports_autosuspend);
233 /* Carry out a deferred switch to altsetting 0 */
234 if (intf->needs_altsetting0) {
235 usb_set_interface(udev, intf->altsetting[0].
236 desc.bInterfaceNumber, 0);
237 intf->needs_altsetting0 = 0;
240 error = driver->probe(intf, id);
243 intf->needs_remote_wakeup = 0;
244 intf->condition = USB_INTERFACE_UNBOUND;
246 intf->condition = USB_INTERFACE_BOUND;
248 usb_autosuspend_device(udev);
254 /* called from driver core with dev locked */
255 static int usb_unbind_interface(struct device *dev)
257 struct usb_driver *driver = to_usb_driver(dev->driver);
258 struct usb_interface *intf = to_usb_interface(dev);
259 struct usb_device *udev;
262 intf->condition = USB_INTERFACE_UNBINDING;
264 /* Autoresume for set_interface call below */
265 udev = interface_to_usbdev(intf);
266 error = usb_autoresume_device(udev);
268 /* Terminate all URBs for this interface unless the driver
269 * supports "soft" unbinding.
271 if (!driver->soft_unbind)
272 usb_disable_interface(udev, intf, false);
274 driver->disconnect(intf);
276 /* Reset other interface state.
277 * We cannot do a Set-Interface if the device is suspended or
278 * if it is prepared for a system sleep (since installing a new
279 * altsetting means creating new endpoint device entries).
280 * When either of these happens, defer the Set-Interface.
282 if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
283 /* Already in altsetting 0 so skip Set-Interface.
284 * Just re-enable it without affecting the endpoint toggles.
286 usb_enable_interface(udev, intf, false);
287 } else if (!error && intf->dev.power.status == DPM_ON)
288 usb_set_interface(udev, intf->altsetting[0].
289 desc.bInterfaceNumber, 0);
291 intf->needs_altsetting0 = 1;
292 usb_set_intfdata(intf, NULL);
294 intf->condition = USB_INTERFACE_UNBOUND;
296 intf->needs_remote_wakeup = 0;
299 usb_autosuspend_device(udev);
305 * usb_driver_claim_interface - bind a driver to an interface
306 * @driver: the driver to be bound
307 * @iface: the interface to which it will be bound; must be in the
308 * usb device's active configuration
309 * @priv: driver data associated with that interface
311 * This is used by usb device drivers that need to claim more than one
312 * interface on a device when probing (audio and acm are current examples).
313 * No device driver should directly modify internal usb_interface or
314 * usb_device structure members.
316 * Few drivers should need to use this routine, since the most natural
317 * way to bind to an interface is to return the private data from
318 * the driver's probe() method.
320 * Callers must own the device lock, so driver probe() entries don't need
321 * extra locking, but other call contexts may need to explicitly claim that
324 int usb_driver_claim_interface(struct usb_driver *driver,
325 struct usb_interface *iface, void *priv)
327 struct device *dev = &iface->dev;
328 struct usb_device *udev = interface_to_usbdev(iface);
334 dev->driver = &driver->drvwrap.driver;
335 usb_set_intfdata(iface, priv);
336 iface->needs_binding = 0;
339 iface->condition = USB_INTERFACE_BOUND;
341 iface->pm_usage_cnt = !(driver->supports_autosuspend);
344 /* if interface was already added, bind now; else let
345 * the future device_add() bind it, bypassing probe()
347 if (device_is_registered(dev))
348 retval = device_bind_driver(dev);
352 EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
355 * usb_driver_release_interface - unbind a driver from an interface
356 * @driver: the driver to be unbound
357 * @iface: the interface from which it will be unbound
359 * This can be used by drivers to release an interface without waiting
360 * for their disconnect() methods to be called. In typical cases this
361 * also causes the driver disconnect() method to be called.
363 * This call is synchronous, and may not be used in an interrupt context.
364 * Callers must own the device lock, so driver disconnect() entries don't
365 * need extra locking, but other call contexts may need to explicitly claim
368 void usb_driver_release_interface(struct usb_driver *driver,
369 struct usb_interface *iface)
371 struct device *dev = &iface->dev;
372 struct usb_device *udev = interface_to_usbdev(iface);
374 /* this should never happen, don't release something that's not ours */
375 if (!dev->driver || dev->driver != &driver->drvwrap.driver)
378 /* don't release from within disconnect() */
379 if (iface->condition != USB_INTERFACE_BOUND)
382 /* don't release if the interface hasn't been added yet */
383 if (device_is_registered(dev)) {
384 iface->condition = USB_INTERFACE_UNBINDING;
385 device_release_driver(dev);
389 usb_set_intfdata(iface, NULL);
392 iface->condition = USB_INTERFACE_UNBOUND;
393 mark_quiesced(iface);
394 iface->needs_remote_wakeup = 0;
397 EXPORT_SYMBOL_GPL(usb_driver_release_interface);
399 /* returns 0 if no match, 1 if match */
400 int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
402 if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
403 id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
406 if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
407 id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
410 /* No need to test id->bcdDevice_lo != 0, since 0 is never
411 greater than any unsigned number. */
412 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
413 (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
416 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
417 (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
420 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
421 (id->bDeviceClass != dev->descriptor.bDeviceClass))
424 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
425 (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
428 if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
429 (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
435 /* returns 0 if no match, 1 if match */
436 int usb_match_one_id(struct usb_interface *interface,
437 const struct usb_device_id *id)
439 struct usb_host_interface *intf;
440 struct usb_device *dev;
442 /* proc_connectinfo in devio.c may call us with id == NULL. */
446 intf = interface->cur_altsetting;
447 dev = interface_to_usbdev(interface);
449 if (!usb_match_device(dev, id))
452 /* The interface class, subclass, and protocol should never be
453 * checked for a match if the device class is Vendor Specific,
454 * unless the match record specifies the Vendor ID. */
455 if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
456 !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
457 (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
458 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
459 USB_DEVICE_ID_MATCH_INT_PROTOCOL)))
462 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
463 (id->bInterfaceClass != intf->desc.bInterfaceClass))
466 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
467 (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
470 if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
471 (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
476 EXPORT_SYMBOL_GPL(usb_match_one_id);
479 * usb_match_id - find first usb_device_id matching device or interface
480 * @interface: the interface of interest
481 * @id: array of usb_device_id structures, terminated by zero entry
483 * usb_match_id searches an array of usb_device_id's and returns
484 * the first one matching the device or interface, or null.
485 * This is used when binding (or rebinding) a driver to an interface.
486 * Most USB device drivers will use this indirectly, through the usb core,
487 * but some layered driver frameworks use it directly.
488 * These device tables are exported with MODULE_DEVICE_TABLE, through
489 * modutils, to support the driver loading functionality of USB hotplugging.
493 * The "match_flags" element in a usb_device_id controls which
494 * members are used. If the corresponding bit is set, the
495 * value in the device_id must match its corresponding member
496 * in the device or interface descriptor, or else the device_id
499 * "driver_info" is normally used only by device drivers,
500 * but you can create a wildcard "matches anything" usb_device_id
501 * as a driver's "modules.usbmap" entry if you provide an id with
502 * only a nonzero "driver_info" field. If you do this, the USB device
503 * driver's probe() routine should use additional intelligence to
504 * decide whether to bind to the specified interface.
506 * What Makes Good usb_device_id Tables:
508 * The match algorithm is very simple, so that intelligence in
509 * driver selection must come from smart driver id records.
510 * Unless you have good reasons to use another selection policy,
511 * provide match elements only in related groups, and order match
512 * specifiers from specific to general. Use the macros provided
513 * for that purpose if you can.
515 * The most specific match specifiers use device descriptor
516 * data. These are commonly used with product-specific matches;
517 * the USB_DEVICE macro lets you provide vendor and product IDs,
518 * and you can also match against ranges of product revisions.
519 * These are widely used for devices with application or vendor
520 * specific bDeviceClass values.
522 * Matches based on device class/subclass/protocol specifications
523 * are slightly more general; use the USB_DEVICE_INFO macro, or
524 * its siblings. These are used with single-function devices
525 * where bDeviceClass doesn't specify that each interface has
528 * Matches based on interface class/subclass/protocol are the
529 * most general; they let drivers bind to any interface on a
530 * multiple-function device. Use the USB_INTERFACE_INFO
531 * macro, or its siblings, to match class-per-interface style
532 * devices (as recorded in bInterfaceClass).
534 * Note that an entry created by USB_INTERFACE_INFO won't match
535 * any interface if the device class is set to Vendor-Specific.
536 * This is deliberate; according to the USB spec the meanings of
537 * the interface class/subclass/protocol for these devices are also
538 * vendor-specific, and hence matching against a standard product
539 * class wouldn't work anyway. If you really want to use an
540 * interface-based match for such a device, create a match record
541 * that also specifies the vendor ID. (Unforunately there isn't a
542 * standard macro for creating records like this.)
544 * Within those groups, remember that not all combinations are
545 * meaningful. For example, don't give a product version range
546 * without vendor and product IDs; or specify a protocol without
547 * its associated class and subclass.
549 const struct usb_device_id *usb_match_id(struct usb_interface *interface,
550 const struct usb_device_id *id)
552 /* proc_connectinfo in devio.c may call us with id == NULL. */
556 /* It is important to check that id->driver_info is nonzero,
557 since an entry that is all zeroes except for a nonzero
558 id->driver_info is the way to create an entry that
559 indicates that the driver want to examine every
560 device and interface. */
561 for (; id->idVendor || id->idProduct || id->bDeviceClass ||
562 id->bInterfaceClass || id->driver_info; id++) {
563 if (usb_match_one_id(interface, id))
569 EXPORT_SYMBOL_GPL(usb_match_id);
571 static int usb_device_match(struct device *dev, struct device_driver *drv)
573 /* devices and interfaces are handled separately */
574 if (is_usb_device(dev)) {
576 /* interface drivers never match devices */
577 if (!is_usb_device_driver(drv))
580 /* TODO: Add real matching code */
584 struct usb_interface *intf;
585 struct usb_driver *usb_drv;
586 const struct usb_device_id *id;
588 /* device drivers never match interfaces */
589 if (is_usb_device_driver(drv))
592 intf = to_usb_interface(dev);
593 usb_drv = to_usb_driver(drv);
595 id = usb_match_id(intf, usb_drv->id_table);
599 id = usb_match_dynamic_id(intf, usb_drv);
607 #ifdef CONFIG_HOTPLUG
608 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
610 struct usb_device *usb_dev;
612 /* driver is often null here; dev_dbg() would oops */
613 pr_debug("usb %s: uevent\n", dev_name(dev));
615 if (is_usb_device(dev))
616 usb_dev = to_usb_device(dev);
618 struct usb_interface *intf = to_usb_interface(dev);
619 usb_dev = interface_to_usbdev(intf);
622 if (usb_dev->devnum < 0) {
623 pr_debug("usb %s: already deleted?\n", dev_name(dev));
627 pr_debug("usb %s: bus removed?\n", dev_name(dev));
631 #ifdef CONFIG_USB_DEVICEFS
632 /* If this is available, userspace programs can directly read
633 * all the device descriptors we don't tell them about. Or
634 * act as usermode drivers.
636 if (add_uevent_var(env, "DEVICE=/proc/bus/usb/%03d/%03d",
637 usb_dev->bus->busnum, usb_dev->devnum))
641 /* per-device configurations are common */
642 if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
643 le16_to_cpu(usb_dev->descriptor.idVendor),
644 le16_to_cpu(usb_dev->descriptor.idProduct),
645 le16_to_cpu(usb_dev->descriptor.bcdDevice)))
648 /* class-based driver binding models */
649 if (add_uevent_var(env, "TYPE=%d/%d/%d",
650 usb_dev->descriptor.bDeviceClass,
651 usb_dev->descriptor.bDeviceSubClass,
652 usb_dev->descriptor.bDeviceProtocol))
660 static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
664 #endif /* CONFIG_HOTPLUG */
667 * usb_register_device_driver - register a USB device (not interface) driver
668 * @new_udriver: USB operations for the device driver
669 * @owner: module owner of this driver.
671 * Registers a USB device driver with the USB core. The list of
672 * unattached devices will be rescanned whenever a new driver is
673 * added, allowing the new driver to attach to any recognized devices.
674 * Returns a negative error code on failure and 0 on success.
676 int usb_register_device_driver(struct usb_device_driver *new_udriver,
677 struct module *owner)
684 new_udriver->drvwrap.for_devices = 1;
685 new_udriver->drvwrap.driver.name = (char *) new_udriver->name;
686 new_udriver->drvwrap.driver.bus = &usb_bus_type;
687 new_udriver->drvwrap.driver.probe = usb_probe_device;
688 new_udriver->drvwrap.driver.remove = usb_unbind_device;
689 new_udriver->drvwrap.driver.owner = owner;
691 retval = driver_register(&new_udriver->drvwrap.driver);
694 pr_info("%s: registered new device driver %s\n",
695 usbcore_name, new_udriver->name);
696 usbfs_update_special();
698 printk(KERN_ERR "%s: error %d registering device "
700 usbcore_name, retval, new_udriver->name);
705 EXPORT_SYMBOL_GPL(usb_register_device_driver);
708 * usb_deregister_device_driver - unregister a USB device (not interface) driver
709 * @udriver: USB operations of the device driver to unregister
710 * Context: must be able to sleep
712 * Unlinks the specified driver from the internal USB driver list.
714 void usb_deregister_device_driver(struct usb_device_driver *udriver)
716 pr_info("%s: deregistering device driver %s\n",
717 usbcore_name, udriver->name);
719 driver_unregister(&udriver->drvwrap.driver);
720 usbfs_update_special();
722 EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
725 * usb_register_driver - register a USB interface driver
726 * @new_driver: USB operations for the interface driver
727 * @owner: module owner of this driver.
728 * @mod_name: module name string
730 * Registers a USB interface driver with the USB core. The list of
731 * unattached interfaces will be rescanned whenever a new driver is
732 * added, allowing the new driver to attach to any recognized interfaces.
733 * Returns a negative error code on failure and 0 on success.
735 * NOTE: if you want your driver to use the USB major number, you must call
736 * usb_register_dev() to enable that functionality. This function no longer
737 * takes care of that.
739 int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
740 const char *mod_name)
747 new_driver->drvwrap.for_devices = 0;
748 new_driver->drvwrap.driver.name = (char *) new_driver->name;
749 new_driver->drvwrap.driver.bus = &usb_bus_type;
750 new_driver->drvwrap.driver.probe = usb_probe_interface;
751 new_driver->drvwrap.driver.remove = usb_unbind_interface;
752 new_driver->drvwrap.driver.owner = owner;
753 new_driver->drvwrap.driver.mod_name = mod_name;
754 spin_lock_init(&new_driver->dynids.lock);
755 INIT_LIST_HEAD(&new_driver->dynids.list);
757 retval = driver_register(&new_driver->drvwrap.driver);
760 pr_info("%s: registered new interface driver %s\n",
761 usbcore_name, new_driver->name);
762 usbfs_update_special();
763 usb_create_newid_file(new_driver);
765 printk(KERN_ERR "%s: error %d registering interface "
767 usbcore_name, retval, new_driver->name);
772 EXPORT_SYMBOL_GPL(usb_register_driver);
775 * usb_deregister - unregister a USB interface driver
776 * @driver: USB operations of the interface driver to unregister
777 * Context: must be able to sleep
779 * Unlinks the specified driver from the internal USB driver list.
781 * NOTE: If you called usb_register_dev(), you still need to call
782 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
783 * this * call will no longer do it for you.
785 void usb_deregister(struct usb_driver *driver)
787 pr_info("%s: deregistering interface driver %s\n",
788 usbcore_name, driver->name);
790 usb_remove_newid_file(driver);
791 usb_free_dynids(driver);
792 driver_unregister(&driver->drvwrap.driver);
794 usbfs_update_special();
796 EXPORT_SYMBOL_GPL(usb_deregister);
798 /* Forced unbinding of a USB interface driver, either because
799 * it doesn't support pre_reset/post_reset/reset_resume or
800 * because it doesn't support suspend/resume.
802 * The caller must hold @intf's device's lock, but not its pm_mutex
803 * and not @intf->dev.sem.
805 void usb_forced_unbind_intf(struct usb_interface *intf)
807 struct usb_driver *driver = to_usb_driver(intf->dev.driver);
809 dev_dbg(&intf->dev, "forced unbind\n");
810 usb_driver_release_interface(driver, intf);
812 /* Mark the interface for later rebinding */
813 intf->needs_binding = 1;
816 /* Delayed forced unbinding of a USB interface driver and scan
819 * The caller must hold @intf's device's lock, but not its pm_mutex
820 * and not @intf->dev.sem.
822 * Note: Rebinds will be skipped if a system sleep transition is in
823 * progress and the PM "complete" callback hasn't occurred yet.
825 void usb_rebind_intf(struct usb_interface *intf)
829 /* Delayed unbind of an existing driver */
830 if (intf->dev.driver) {
831 struct usb_driver *driver =
832 to_usb_driver(intf->dev.driver);
834 dev_dbg(&intf->dev, "forced unbind\n");
835 usb_driver_release_interface(driver, intf);
838 /* Try to rebind the interface */
839 if (intf->dev.power.status == DPM_ON) {
840 intf->needs_binding = 0;
841 rc = device_attach(&intf->dev);
843 dev_warn(&intf->dev, "rebind failed: %d\n", rc);
852 /* Unbind drivers for @udev's interfaces that don't support suspend/resume,
853 * or rebind interfaces that have been unbound, according to @action.
855 * The caller must hold @udev's device lock.
857 static void do_unbind_rebind(struct usb_device *udev, int action)
859 struct usb_host_config *config;
861 struct usb_interface *intf;
862 struct usb_driver *drv;
864 config = udev->actconfig;
866 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
867 intf = config->interface[i];
870 if (intf->dev.driver) {
871 drv = to_usb_driver(intf->dev.driver);
872 if (!drv->suspend || !drv->resume)
873 usb_forced_unbind_intf(intf);
877 if (intf->needs_binding)
878 usb_rebind_intf(intf);
885 /* Caller has locked udev's pm_mutex */
886 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
888 struct usb_device_driver *udriver;
891 if (udev->state == USB_STATE_NOTATTACHED ||
892 udev->state == USB_STATE_SUSPENDED)
895 /* For devices that don't have a driver, we do a generic suspend. */
896 if (udev->dev.driver)
897 udriver = to_usb_device_driver(udev->dev.driver);
899 udev->do_remote_wakeup = 0;
900 udriver = &usb_generic_driver;
902 status = udriver->suspend(udev, msg);
905 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
909 /* Caller has locked udev's pm_mutex */
910 static int usb_resume_device(struct usb_device *udev)
912 struct usb_device_driver *udriver;
915 if (udev->state == USB_STATE_NOTATTACHED)
918 /* Can't resume it if it doesn't have a driver. */
919 if (udev->dev.driver == NULL) {
924 if (udev->quirks & USB_QUIRK_RESET_RESUME)
925 udev->reset_resume = 1;
927 udriver = to_usb_device_driver(udev->dev.driver);
928 status = udriver->resume(udev);
931 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
933 udev->autoresume_disabled = 0;
937 /* Caller has locked intf's usb_device's pm mutex */
938 static int usb_suspend_interface(struct usb_device *udev,
939 struct usb_interface *intf, pm_message_t msg)
941 struct usb_driver *driver;
944 /* with no hardware, USB interfaces only use FREEZE and ON states */
945 if (udev->state == USB_STATE_NOTATTACHED || !is_active(intf))
948 if (intf->condition == USB_INTERFACE_UNBOUND) /* This can't happen */
950 driver = to_usb_driver(intf->dev.driver);
952 if (driver->suspend) {
953 status = driver->suspend(intf, msg);
956 else if (!udev->auto_pm)
957 dev_err(&intf->dev, "%s error %d\n",
960 /* Later we will unbind the driver and reprobe */
961 intf->needs_binding = 1;
962 dev_warn(&intf->dev, "no %s for driver %s?\n",
963 "suspend", driver->name);
968 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
972 /* Caller has locked intf's usb_device's pm_mutex */
973 static int usb_resume_interface(struct usb_device *udev,
974 struct usb_interface *intf, int reset_resume)
976 struct usb_driver *driver;
979 if (udev->state == USB_STATE_NOTATTACHED || is_active(intf))
982 /* Don't let autoresume interfere with unbinding */
983 if (intf->condition == USB_INTERFACE_UNBINDING)
986 /* Can't resume it if it doesn't have a driver. */
987 if (intf->condition == USB_INTERFACE_UNBOUND) {
989 /* Carry out a deferred switch to altsetting 0 */
990 if (intf->needs_altsetting0 &&
991 intf->dev.power.status == DPM_ON) {
992 usb_set_interface(udev, intf->altsetting[0].
993 desc.bInterfaceNumber, 0);
994 intf->needs_altsetting0 = 0;
999 /* Don't resume if the interface is marked for rebinding */
1000 if (intf->needs_binding)
1002 driver = to_usb_driver(intf->dev.driver);
1005 if (driver->reset_resume) {
1006 status = driver->reset_resume(intf);
1008 dev_err(&intf->dev, "%s error %d\n",
1009 "reset_resume", status);
1011 intf->needs_binding = 1;
1012 dev_warn(&intf->dev, "no %s for driver %s?\n",
1013 "reset_resume", driver->name);
1016 if (driver->resume) {
1017 status = driver->resume(intf);
1019 dev_err(&intf->dev, "%s error %d\n",
1022 intf->needs_binding = 1;
1023 dev_warn(&intf->dev, "no %s for driver %s?\n",
1024 "resume", driver->name);
1029 dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1030 if (status == 0 && intf->condition == USB_INTERFACE_BOUND)
1033 /* Later we will unbind the driver and/or reprobe, if necessary */
1037 #ifdef CONFIG_USB_SUSPEND
1039 /* Internal routine to check whether we may autosuspend a device. */
1040 static int autosuspend_check(struct usb_device *udev, int reschedule)
1043 struct usb_interface *intf;
1044 unsigned long suspend_time, j;
1046 /* For autosuspend, fail fast if anything is in use or autosuspend
1047 * is disabled. Also fail if any interfaces require remote wakeup
1048 * but it isn't available.
1050 if (udev->pm_usage_cnt > 0)
1052 if (udev->autosuspend_delay < 0 || udev->autosuspend_disabled)
1055 suspend_time = udev->last_busy + udev->autosuspend_delay;
1056 if (udev->actconfig) {
1057 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1058 intf = udev->actconfig->interface[i];
1059 if (!is_active(intf))
1061 if (intf->pm_usage_cnt > 0)
1063 if (intf->needs_remote_wakeup &&
1064 !udev->do_remote_wakeup) {
1065 dev_dbg(&udev->dev, "remote wakeup needed "
1066 "for autosuspend\n");
1070 /* Don't allow autosuspend if the device will need
1071 * a reset-resume and any of its interface drivers
1072 * doesn't include support.
1074 if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1075 struct usb_driver *driver;
1077 driver = to_usb_driver(intf->dev.driver);
1078 if (!driver->reset_resume ||
1079 intf->needs_remote_wakeup)
1085 /* If everything is okay but the device hasn't been idle for long
1086 * enough, queue a delayed autosuspend request. If the device
1087 * _has_ been idle for long enough and the reschedule flag is set,
1088 * likewise queue a delayed (1 second) autosuspend request.
1091 if (time_before(j, suspend_time))
1094 suspend_time = j + HZ;
1096 if (!timer_pending(&udev->autosuspend.timer)) {
1097 queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
1098 round_jiffies_relative(suspend_time - j));
1107 static inline int autosuspend_check(struct usb_device *udev, int reschedule)
1112 #endif /* CONFIG_USB_SUSPEND */
1115 * usb_suspend_both - suspend a USB device and its interfaces
1116 * @udev: the usb_device to suspend
1117 * @msg: Power Management message describing this state transition
1119 * This is the central routine for suspending USB devices. It calls the
1120 * suspend methods for all the interface drivers in @udev and then calls
1121 * the suspend method for @udev itself. If an error occurs at any stage,
1122 * all the interfaces which were suspended are resumed so that they remain
1123 * in the same state as the device.
1125 * If an autosuspend is in progress (@udev->auto_pm is set), the routine
1126 * checks first to make sure that neither the device itself or any of its
1127 * active interfaces is in use (pm_usage_cnt is greater than 0). If they
1128 * are, the autosuspend fails.
1130 * If the suspend succeeds, the routine recursively queues an autosuspend
1131 * request for @udev's parent device, thereby propagating the change up
1132 * the device tree. If all of the parent's children are now suspended,
1133 * the parent will autosuspend in turn.
1135 * The suspend method calls are subject to mutual exclusion under control
1136 * of @udev's pm_mutex. Many of these calls are also under the protection
1137 * of @udev's device lock (including all requests originating outside the
1138 * USB subsystem), but autosuspend requests generated by a child device or
1139 * interface driver may not be. Usbcore will insure that the method calls
1140 * do not arrive during bind, unbind, or reset operations. However, drivers
1141 * must be prepared to handle suspend calls arriving at unpredictable times.
1142 * The only way to block such calls is to do an autoresume (preventing
1143 * autosuspends) while holding @udev's device lock (preventing outside
1146 * The caller must hold @udev->pm_mutex.
1148 * This routine can run only in process context.
1150 static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1154 struct usb_interface *intf;
1155 struct usb_device *parent = udev->parent;
1157 if (udev->state == USB_STATE_NOTATTACHED ||
1158 udev->state == USB_STATE_SUSPENDED)
1161 udev->do_remote_wakeup = device_may_wakeup(&udev->dev);
1163 if (udev->auto_pm) {
1164 status = autosuspend_check(udev, 0);
1169 /* Suspend all the interfaces and then udev itself */
1170 if (udev->actconfig) {
1171 for (; i < udev->actconfig->desc.bNumInterfaces; i++) {
1172 intf = udev->actconfig->interface[i];
1173 status = usb_suspend_interface(udev, intf, msg);
1179 status = usb_suspend_device(udev, msg);
1181 /* If the suspend failed, resume interfaces that did get suspended */
1184 intf = udev->actconfig->interface[i];
1185 usb_resume_interface(udev, intf, 0);
1188 /* Try another autosuspend when the interfaces aren't busy */
1190 autosuspend_check(udev, status == -EBUSY);
1192 /* If the suspend succeeded then prevent any more URB submissions,
1193 * flush any outstanding URBs, and propagate the suspend up the tree.
1196 cancel_delayed_work(&udev->autosuspend);
1197 udev->can_submit = 0;
1198 for (i = 0; i < 16; ++i) {
1199 usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1200 usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1203 /* If this is just a FREEZE or a PRETHAW, udev might
1204 * not really be suspended. Only true suspends get
1205 * propagated up the device tree.
1207 if (parent && udev->state == USB_STATE_SUSPENDED)
1208 usb_autosuspend_device(parent);
1212 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1217 * usb_resume_both - resume a USB device and its interfaces
1218 * @udev: the usb_device to resume
1220 * This is the central routine for resuming USB devices. It calls the
1221 * the resume method for @udev and then calls the resume methods for all
1222 * the interface drivers in @udev.
1224 * Before starting the resume, the routine calls itself recursively for
1225 * the parent device of @udev, thereby propagating the change up the device
1226 * tree and assuring that @udev will be able to resume. If the parent is
1227 * unable to resume successfully, the routine fails.
1229 * The resume method calls are subject to mutual exclusion under control
1230 * of @udev's pm_mutex. Many of these calls are also under the protection
1231 * of @udev's device lock (including all requests originating outside the
1232 * USB subsystem), but autoresume requests generated by a child device or
1233 * interface driver may not be. Usbcore will insure that the method calls
1234 * do not arrive during bind, unbind, or reset operations. However, drivers
1235 * must be prepared to handle resume calls arriving at unpredictable times.
1236 * The only way to block such calls is to do an autoresume (preventing
1237 * other autoresumes) while holding @udev's device lock (preventing outside
1240 * The caller must hold @udev->pm_mutex.
1242 * This routine can run only in process context.
1244 static int usb_resume_both(struct usb_device *udev)
1248 struct usb_interface *intf;
1249 struct usb_device *parent = udev->parent;
1251 cancel_delayed_work(&udev->autosuspend);
1252 if (udev->state == USB_STATE_NOTATTACHED) {
1256 udev->can_submit = 1;
1258 /* Propagate the resume up the tree, if necessary */
1259 if (udev->state == USB_STATE_SUSPENDED) {
1260 if (udev->auto_pm && udev->autoresume_disabled) {
1265 status = usb_autoresume_device(parent);
1267 status = usb_resume_device(udev);
1268 if (status || udev->state ==
1269 USB_STATE_NOTATTACHED) {
1270 usb_autosuspend_device(parent);
1272 /* It's possible usb_resume_device()
1273 * failed after the port was
1274 * unsuspended, causing udev to be
1275 * logically disconnected. We don't
1276 * want usb_disconnect() to autosuspend
1277 * the parent again, so tell it that
1278 * udev disconnected while still
1281 USB_STATE_NOTATTACHED)
1282 udev->discon_suspended = 1;
1287 /* We can't progagate beyond the USB subsystem,
1288 * so if a root hub's controller is suspended
1289 * then we're stuck. */
1290 status = usb_resume_device(udev);
1292 } else if (udev->reset_resume)
1293 status = usb_resume_device(udev);
1295 if (status == 0 && udev->actconfig) {
1296 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1297 intf = udev->actconfig->interface[i];
1298 usb_resume_interface(udev, intf, udev->reset_resume);
1303 dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1305 udev->reset_resume = 0;
1309 #ifdef CONFIG_USB_SUSPEND
1311 /* Internal routine to adjust a device's usage counter and change
1312 * its autosuspend state.
1314 static int usb_autopm_do_device(struct usb_device *udev, int inc_usage_cnt)
1320 udev->pm_usage_cnt += inc_usage_cnt;
1321 WARN_ON(udev->pm_usage_cnt < 0);
1323 udev->last_busy = jiffies;
1324 if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) {
1325 if (udev->state == USB_STATE_SUSPENDED)
1326 status = usb_resume_both(udev);
1328 udev->pm_usage_cnt -= inc_usage_cnt;
1329 else if (inc_usage_cnt)
1330 udev->last_busy = jiffies;
1331 } else if (inc_usage_cnt <= 0 && udev->pm_usage_cnt <= 0) {
1332 status = usb_suspend_both(udev, PMSG_SUSPEND);
1334 usb_pm_unlock(udev);
1338 /* usb_autosuspend_work - callback routine to autosuspend a USB device */
1339 void usb_autosuspend_work(struct work_struct *work)
1341 struct usb_device *udev =
1342 container_of(work, struct usb_device, autosuspend.work);
1344 usb_autopm_do_device(udev, 0);
1348 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1349 * @udev: the usb_device to autosuspend
1351 * This routine should be called when a core subsystem is finished using
1352 * @udev and wants to allow it to autosuspend. Examples would be when
1353 * @udev's device file in usbfs is closed or after a configuration change.
1355 * @udev's usage counter is decremented. If it or any of the usage counters
1356 * for an active interface is greater than 0, no autosuspend request will be
1357 * queued. (If an interface driver does not support autosuspend then its
1358 * usage counter is permanently positive.) Furthermore, if an interface
1359 * driver requires remote-wakeup capability during autosuspend but remote
1360 * wakeup is disabled, the autosuspend will fail.
1362 * Often the caller will hold @udev's device lock, but this is not
1365 * This routine can run only in process context.
1367 void usb_autosuspend_device(struct usb_device *udev)
1371 status = usb_autopm_do_device(udev, -1);
1372 dev_vdbg(&udev->dev, "%s: cnt %d\n",
1373 __func__, udev->pm_usage_cnt);
1377 * usb_try_autosuspend_device - attempt an autosuspend of a USB device and its interfaces
1378 * @udev: the usb_device to autosuspend
1380 * This routine should be called when a core subsystem thinks @udev may
1381 * be ready to autosuspend.
1383 * @udev's usage counter left unchanged. If it or any of the usage counters
1384 * for an active interface is greater than 0, or autosuspend is not allowed
1385 * for any other reason, no autosuspend request will be queued.
1387 * This routine can run only in process context.
1389 void usb_try_autosuspend_device(struct usb_device *udev)
1391 usb_autopm_do_device(udev, 0);
1392 dev_vdbg(&udev->dev, "%s: cnt %d\n",
1393 __func__, udev->pm_usage_cnt);
1397 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1398 * @udev: the usb_device to autoresume
1400 * This routine should be called when a core subsystem wants to use @udev
1401 * and needs to guarantee that it is not suspended. No autosuspend will
1402 * occur until usb_autosuspend_device is called. (Note that this will not
1403 * prevent suspend events originating in the PM core.) Examples would be
1404 * when @udev's device file in usbfs is opened or when a remote-wakeup
1405 * request is received.
1407 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1408 * However if the autoresume fails then the usage counter is re-decremented.
1410 * Often the caller will hold @udev's device lock, but this is not
1411 * necessary (and attempting it might cause deadlock).
1413 * This routine can run only in process context.
1415 int usb_autoresume_device(struct usb_device *udev)
1419 status = usb_autopm_do_device(udev, 1);
1420 dev_vdbg(&udev->dev, "%s: status %d cnt %d\n",
1421 __func__, status, udev->pm_usage_cnt);
1425 /* Internal routine to adjust an interface's usage counter and change
1426 * its device's autosuspend state.
1428 static int usb_autopm_do_interface(struct usb_interface *intf,
1431 struct usb_device *udev = interface_to_usbdev(intf);
1435 if (intf->condition == USB_INTERFACE_UNBOUND)
1439 intf->pm_usage_cnt += inc_usage_cnt;
1440 udev->last_busy = jiffies;
1441 if (inc_usage_cnt >= 0 && intf->pm_usage_cnt > 0) {
1442 if (udev->state == USB_STATE_SUSPENDED)
1443 status = usb_resume_both(udev);
1445 intf->pm_usage_cnt -= inc_usage_cnt;
1447 udev->last_busy = jiffies;
1448 } else if (inc_usage_cnt <= 0 && intf->pm_usage_cnt <= 0) {
1449 status = usb_suspend_both(udev, PMSG_SUSPEND);
1452 usb_pm_unlock(udev);
1457 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1458 * @intf: the usb_interface whose counter should be decremented
1460 * This routine should be called by an interface driver when it is
1461 * finished using @intf and wants to allow it to autosuspend. A typical
1462 * example would be a character-device driver when its device file is
1465 * The routine decrements @intf's usage counter. When the counter reaches
1466 * 0, a delayed autosuspend request for @intf's device is queued. When
1467 * the delay expires, if @intf->pm_usage_cnt is still <= 0 along with all
1468 * the other usage counters for the sibling interfaces and @intf's
1469 * usb_device, the device and all its interfaces will be autosuspended.
1471 * Note that @intf->pm_usage_cnt is owned by the interface driver. The
1472 * core will not change its value other than the increment and decrement
1473 * in usb_autopm_get_interface and usb_autopm_put_interface. The driver
1474 * may use this simple counter-oriented discipline or may set the value
1477 * If the driver has set @intf->needs_remote_wakeup then autosuspend will
1478 * take place only if the device's remote-wakeup facility is enabled.
1480 * Suspend method calls queued by this routine can arrive at any time
1481 * while @intf is resumed and its usage counter is equal to 0. They are
1482 * not protected by the usb_device's lock but only by its pm_mutex.
1483 * Drivers must provide their own synchronization.
1485 * This routine can run only in process context.
1487 void usb_autopm_put_interface(struct usb_interface *intf)
1491 status = usb_autopm_do_interface(intf, -1);
1492 dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
1493 __func__, status, intf->pm_usage_cnt);
1495 EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1498 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1499 * @intf: the usb_interface whose counter should be incremented
1501 * This routine should be called by an interface driver when it wants to
1502 * use @intf and needs to guarantee that it is not suspended. In addition,
1503 * the routine prevents @intf from being autosuspended subsequently. (Note
1504 * that this will not prevent suspend events originating in the PM core.)
1505 * This prevention will persist until usb_autopm_put_interface() is called
1506 * or @intf is unbound. A typical example would be a character-device
1507 * driver when its device file is opened.
1510 * The routine increments @intf's usage counter. (However if the
1511 * autoresume fails then the counter is re-decremented.) So long as the
1512 * counter is greater than 0, autosuspend will not be allowed for @intf
1513 * or its usb_device. When the driver is finished using @intf it should
1514 * call usb_autopm_put_interface() to decrement the usage counter and
1515 * queue a delayed autosuspend request (if the counter is <= 0).
1518 * Note that @intf->pm_usage_cnt is owned by the interface driver. The
1519 * core will not change its value other than the increment and decrement
1520 * in usb_autopm_get_interface and usb_autopm_put_interface. The driver
1521 * may use this simple counter-oriented discipline or may set the value
1524 * Resume method calls generated by this routine can arrive at any time
1525 * while @intf is suspended. They are not protected by the usb_device's
1526 * lock but only by its pm_mutex. Drivers must provide their own
1529 * This routine can run only in process context.
1531 int usb_autopm_get_interface(struct usb_interface *intf)
1535 status = usb_autopm_do_interface(intf, 1);
1536 dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
1537 __func__, status, intf->pm_usage_cnt);
1540 EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1543 * usb_autopm_set_interface - set a USB interface's autosuspend state
1544 * @intf: the usb_interface whose state should be set
1546 * This routine sets the autosuspend state of @intf's device according
1547 * to @intf's usage counter, which the caller must have set previously.
1548 * If the counter is <= 0, the device is autosuspended (if it isn't
1549 * already suspended and if nothing else prevents the autosuspend). If
1550 * the counter is > 0, the device is autoresumed (if it isn't already
1553 int usb_autopm_set_interface(struct usb_interface *intf)
1557 status = usb_autopm_do_interface(intf, 0);
1558 dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
1559 __func__, status, intf->pm_usage_cnt);
1562 EXPORT_SYMBOL_GPL(usb_autopm_set_interface);
1566 void usb_autosuspend_work(struct work_struct *work)
1569 #endif /* CONFIG_USB_SUSPEND */
1572 * usb_external_suspend_device - external suspend of a USB device and its interfaces
1573 * @udev: the usb_device to suspend
1574 * @msg: Power Management message describing this state transition
1576 * This routine handles external suspend requests: ones not generated
1577 * internally by a USB driver (autosuspend) but rather coming from the user
1578 * (via sysfs) or the PM core (system sleep). The suspend will be carried
1579 * out regardless of @udev's usage counter or those of its interfaces,
1580 * and regardless of whether or not remote wakeup is enabled. Of course,
1581 * interface drivers still have the option of failing the suspend (if
1582 * there are unsuspended children, for example).
1584 * The caller must hold @udev's device lock.
1586 int usb_external_suspend_device(struct usb_device *udev, pm_message_t msg)
1590 do_unbind_rebind(udev, DO_UNBIND);
1593 status = usb_suspend_both(udev, msg);
1594 usb_pm_unlock(udev);
1599 * usb_external_resume_device - external resume of a USB device and its interfaces
1600 * @udev: the usb_device to resume
1602 * This routine handles external resume requests: ones not generated
1603 * internally by a USB driver (autoresume) but rather coming from the user
1604 * (via sysfs), the PM core (system resume), or the device itself (remote
1605 * wakeup). @udev's usage counter is unaffected.
1607 * The caller must hold @udev's device lock.
1609 int usb_external_resume_device(struct usb_device *udev)
1615 status = usb_resume_both(udev);
1616 udev->last_busy = jiffies;
1617 usb_pm_unlock(udev);
1619 do_unbind_rebind(udev, DO_REBIND);
1621 /* Now that the device is awake, we can start trying to autosuspend
1624 usb_try_autosuspend_device(udev);
1628 int usb_suspend(struct device *dev, pm_message_t message)
1630 struct usb_device *udev;
1632 udev = to_usb_device(dev);
1634 /* If udev is already suspended, we can skip this suspend and
1635 * we should also skip the upcoming system resume. High-speed
1636 * root hubs are an exception; they need to resume whenever the
1637 * system wakes up in order for USB-PERSIST port handover to work
1640 if (udev->state == USB_STATE_SUSPENDED) {
1641 if (udev->parent || udev->speed != USB_SPEED_HIGH)
1642 udev->skip_sys_resume = 1;
1646 udev->skip_sys_resume = 0;
1647 return usb_external_suspend_device(udev, message);
1650 int usb_resume(struct device *dev)
1652 struct usb_device *udev;
1654 udev = to_usb_device(dev);
1656 /* If udev->skip_sys_resume is set then udev was already suspended
1657 * when the system sleep started, so we don't want to resume it
1658 * during this system wakeup.
1660 if (udev->skip_sys_resume)
1662 return usb_external_resume_device(udev);
1665 #endif /* CONFIG_PM */
1667 struct bus_type usb_bus_type = {
1669 .match = usb_device_match,
1670 .uevent = usb_uevent,