244 lines
6.8 KiB
C
244 lines
6.8 KiB
C
/*
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* drivers/usb/generic.c - generic driver for USB devices (not interfaces)
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*
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* (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
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*
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* based on drivers/usb/usb.c which had the following copyrights:
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* (C) Copyright Linus Torvalds 1999
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* (C) Copyright Johannes Erdfelt 1999-2001
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* (C) Copyright Andreas Gal 1999
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* (C) Copyright Gregory P. Smith 1999
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* (C) Copyright Deti Fliegl 1999 (new USB architecture)
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* (C) Copyright Randy Dunlap 2000
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* (C) Copyright David Brownell 2000-2004
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* (C) Copyright Yggdrasil Computing, Inc. 2000
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* (usb_device_id matching changes by Adam J. Richter)
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* (C) Copyright Greg Kroah-Hartman 2002-2003
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*
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*/
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#include <linux/usb.h>
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#include "usb.h"
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#include "hcd.h"
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static inline const char *plural(int n)
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{
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return (n == 1 ? "" : "s");
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}
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static int is_rndis(struct usb_interface_descriptor *desc)
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{
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return desc->bInterfaceClass == USB_CLASS_COMM
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&& desc->bInterfaceSubClass == 2
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&& desc->bInterfaceProtocol == 0xff;
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}
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static int is_activesync(struct usb_interface_descriptor *desc)
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{
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return desc->bInterfaceClass == USB_CLASS_MISC
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&& desc->bInterfaceSubClass == 1
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&& desc->bInterfaceProtocol == 1;
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}
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int usb_choose_configuration(struct usb_device *udev)
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{
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int i;
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int num_configs;
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int insufficient_power = 0;
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struct usb_host_config *c, *best;
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best = NULL;
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c = udev->config;
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num_configs = udev->descriptor.bNumConfigurations;
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for (i = 0; i < num_configs; (i++, c++)) {
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struct usb_interface_descriptor *desc = NULL;
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/* It's possible that a config has no interfaces! */
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if (c->desc.bNumInterfaces > 0)
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desc = &c->intf_cache[0]->altsetting->desc;
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/*
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* HP's USB bus-powered keyboard has only one configuration
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* and it claims to be self-powered; other devices may have
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* similar errors in their descriptors. If the next test
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* were allowed to execute, such configurations would always
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* be rejected and the devices would not work as expected.
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* In the meantime, we run the risk of selecting a config
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* that requires external power at a time when that power
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* isn't available. It seems to be the lesser of two evils.
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*
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* Bugzilla #6448 reports a device that appears to crash
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* when it receives a GET_DEVICE_STATUS request! We don't
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* have any other way to tell whether a device is self-powered,
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* but since we don't use that information anywhere but here,
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* the call has been removed.
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*
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* Maybe the GET_DEVICE_STATUS call and the test below can
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* be reinstated when device firmwares become more reliable.
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* Don't hold your breath.
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*/
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#if 0
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/* Rule out self-powered configs for a bus-powered device */
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if (bus_powered && (c->desc.bmAttributes &
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USB_CONFIG_ATT_SELFPOWER))
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continue;
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#endif
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/*
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* The next test may not be as effective as it should be.
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* Some hubs have errors in their descriptor, claiming
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* to be self-powered when they are really bus-powered.
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* We will overestimate the amount of current such hubs
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* make available for each port.
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*
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* This is a fairly benign sort of failure. It won't
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* cause us to reject configurations that we should have
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* accepted.
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*/
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/* Rule out configs that draw too much bus current */
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if (c->desc.bMaxPower * 2 > udev->bus_mA) {
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insufficient_power++;
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continue;
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}
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/* When the first config's first interface is one of Microsoft's
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* pet nonstandard Ethernet-over-USB protocols, ignore it unless
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* this kernel has enabled the necessary host side driver.
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*/
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if (i == 0 && desc && (is_rndis(desc) || is_activesync(desc))) {
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#if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE)
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continue;
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#else
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best = c;
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#endif
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}
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/* From the remaining configs, choose the first one whose
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* first interface is for a non-vendor-specific class.
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* Reason: Linux is more likely to have a class driver
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* than a vendor-specific driver. */
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else if (udev->descriptor.bDeviceClass !=
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USB_CLASS_VENDOR_SPEC &&
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(!desc || desc->bInterfaceClass !=
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USB_CLASS_VENDOR_SPEC)) {
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best = c;
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break;
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}
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/* If all the remaining configs are vendor-specific,
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* choose the first one. */
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else if (!best)
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best = c;
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}
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if (insufficient_power > 0)
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dev_info(&udev->dev, "rejected %d configuration%s "
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"due to insufficient available bus power\n",
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insufficient_power, plural(insufficient_power));
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if (best) {
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i = best->desc.bConfigurationValue;
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dev_dbg(&udev->dev,
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"configuration #%d chosen from %d choice%s\n",
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i, num_configs, plural(num_configs));
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} else {
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i = -1;
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dev_warn(&udev->dev,
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"no configuration chosen from %d choice%s\n",
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num_configs, plural(num_configs));
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}
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return i;
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}
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static int generic_probe(struct usb_device *udev)
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{
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int err, c;
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/* Choose and set the configuration. This registers the interfaces
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* with the driver core and lets interface drivers bind to them.
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*/
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if (usb_device_is_owned(udev))
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; /* Don't configure if the device is owned */
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else if (udev->authorized == 0)
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dev_err(&udev->dev, "Device is not authorized for usage\n");
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else {
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c = usb_choose_configuration(udev);
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if (c >= 0) {
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err = usb_set_configuration(udev, c);
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if (err) {
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dev_err(&udev->dev, "can't set config #%d, error %d\n",
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c, err);
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/* This need not be fatal. The user can try to
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* set other configurations. */
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}
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}
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}
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/* USB device state == configured ... usable */
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usb_notify_add_device(udev);
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return 0;
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}
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static void generic_disconnect(struct usb_device *udev)
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{
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usb_notify_remove_device(udev);
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/* if this is only an unbind, not a physical disconnect, then
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* unconfigure the device */
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if (udev->actconfig)
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usb_set_configuration(udev, -1);
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}
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#ifdef CONFIG_PM
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static int generic_suspend(struct usb_device *udev, pm_message_t msg)
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{
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int rc;
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/* Normal USB devices suspend through their upstream port.
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* Root hubs don't have upstream ports to suspend,
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* so we have to shut down their downstream HC-to-USB
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* interfaces manually by doing a bus (or "global") suspend.
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*/
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if (!udev->parent)
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rc = hcd_bus_suspend(udev, msg);
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/* Non-root devices don't need to do anything for FREEZE or PRETHAW */
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else if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW)
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rc = 0;
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else
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rc = usb_port_suspend(udev, msg);
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return rc;
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}
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static int generic_resume(struct usb_device *udev, pm_message_t msg)
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{
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int rc;
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/* Normal USB devices resume/reset through their upstream port.
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* Root hubs don't have upstream ports to resume or reset,
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* so we have to start up their downstream HC-to-USB
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* interfaces manually by doing a bus (or "global") resume.
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*/
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if (!udev->parent)
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rc = hcd_bus_resume(udev, msg);
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else
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rc = usb_port_resume(udev, msg);
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return rc;
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}
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#endif /* CONFIG_PM */
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struct usb_device_driver usb_generic_driver = {
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.name = "usb",
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.probe = generic_probe,
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.disconnect = generic_disconnect,
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#ifdef CONFIG_PM
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.suspend = generic_suspend,
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.resume = generic_resume,
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#endif
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.supports_autosuspend = 1,
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};
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