![David Brownell](/assets/img/avatar_default.png)
This patch updates some of the documentation about DMA buffer management for USB, and ways to avoid extra copying. Our understanding of the issues has improved over time. - Most drivers should *avoid* the dma-coherent allocators. There are a few exceptions (like the HID driver). - Some methods are currently commented out; it seems folk writing USB drivers aren't doing performance tuning at that level yet. - Just avoid highmem; there's no good way to pass an "I can do highmem DMA" capability through a driver stack. This is easy, everything already avoids highmem. But it'd be nice if x86_32 systems with much physical memory could use it directly with network adapters and mass storage devices. (Patch, anyone?) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
985 lines
28 KiB
C
985 lines
28 KiB
C
/*
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* drivers/usb/core/usb.c
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*
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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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* NOTE! This is not actually a driver at all, rather this is
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* just a collection of helper routines that implement the
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* generic USB things that the real drivers can use..
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*
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* Think of this as a "USB library" rather than anything else.
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* It should be considered a slave, with no callbacks. Callbacks
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* are evil.
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/string.h>
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#include <linux/bitops.h>
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#include <linux/slab.h>
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#include <linux/interrupt.h> /* for in_interrupt() */
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#include <linux/kmod.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/errno.h>
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#include <linux/usb.h>
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#include <linux/mutex.h>
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#include <linux/workqueue.h>
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#include <asm/io.h>
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#include <asm/scatterlist.h>
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#include <linux/mm.h>
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#include <linux/dma-mapping.h>
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#include "hcd.h"
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#include "usb.h"
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const char *usbcore_name = "usbcore";
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static int nousb; /* Disable USB when built into kernel image */
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/* Workqueue for autosuspend and for remote wakeup of root hubs */
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struct workqueue_struct *ksuspend_usb_wq;
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#ifdef CONFIG_USB_SUSPEND
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static int usb_autosuspend_delay = 2; /* Default delay value,
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* in seconds */
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module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
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MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
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#else
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#define usb_autosuspend_delay 0
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#endif
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/**
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* usb_ifnum_to_if - get the interface object with a given interface number
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* @dev: the device whose current configuration is considered
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* @ifnum: the desired interface
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*
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* This walks the device descriptor for the currently active configuration
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* and returns a pointer to the interface with that particular interface
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* number, or null.
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*
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* Note that configuration descriptors are not required to assign interface
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* numbers sequentially, so that it would be incorrect to assume that
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* the first interface in that descriptor corresponds to interface zero.
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* This routine helps device drivers avoid such mistakes.
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* However, you should make sure that you do the right thing with any
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* alternate settings available for this interfaces.
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*
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* Don't call this function unless you are bound to one of the interfaces
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* on this device or you have locked the device!
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*/
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struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
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unsigned ifnum)
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{
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struct usb_host_config *config = dev->actconfig;
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int i;
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if (!config)
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return NULL;
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for (i = 0; i < config->desc.bNumInterfaces; i++)
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if (config->interface[i]->altsetting[0]
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.desc.bInterfaceNumber == ifnum)
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return config->interface[i];
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return NULL;
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}
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/**
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* usb_altnum_to_altsetting - get the altsetting structure with a given
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* alternate setting number.
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* @intf: the interface containing the altsetting in question
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* @altnum: the desired alternate setting number
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*
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* This searches the altsetting array of the specified interface for
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* an entry with the correct bAlternateSetting value and returns a pointer
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* to that entry, or null.
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*
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* Note that altsettings need not be stored sequentially by number, so
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* it would be incorrect to assume that the first altsetting entry in
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* the array corresponds to altsetting zero. This routine helps device
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* drivers avoid such mistakes.
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*
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* Don't call this function unless you are bound to the intf interface
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* or you have locked the device!
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*/
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struct usb_host_interface *usb_altnum_to_altsetting(const struct usb_interface *intf,
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unsigned int altnum)
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{
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int i;
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for (i = 0; i < intf->num_altsetting; i++) {
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if (intf->altsetting[i].desc.bAlternateSetting == altnum)
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return &intf->altsetting[i];
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}
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return NULL;
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}
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struct find_interface_arg {
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int minor;
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struct usb_interface *interface;
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};
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static int __find_interface(struct device * dev, void * data)
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{
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struct find_interface_arg *arg = data;
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struct usb_interface *intf;
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/* can't look at usb devices, only interfaces */
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if (is_usb_device(dev))
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return 0;
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intf = to_usb_interface(dev);
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if (intf->minor != -1 && intf->minor == arg->minor) {
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arg->interface = intf;
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return 1;
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}
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return 0;
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}
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/**
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* usb_find_interface - find usb_interface pointer for driver and device
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* @drv: the driver whose current configuration is considered
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* @minor: the minor number of the desired device
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*
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* This walks the driver device list and returns a pointer to the interface
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* with the matching minor. Note, this only works for devices that share the
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* USB major number.
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*/
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struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
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{
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struct find_interface_arg argb;
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int retval;
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argb.minor = minor;
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argb.interface = NULL;
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/* eat the error, it will be in argb.interface */
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retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb,
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__find_interface);
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return argb.interface;
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}
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/**
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* usb_release_dev - free a usb device structure when all users of it are finished.
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* @dev: device that's been disconnected
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*
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* Will be called only by the device core when all users of this usb device are
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* done.
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*/
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static void usb_release_dev(struct device *dev)
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{
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struct usb_device *udev;
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udev = to_usb_device(dev);
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usb_destroy_configuration(udev);
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usb_put_hcd(bus_to_hcd(udev->bus));
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kfree(udev->product);
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kfree(udev->manufacturer);
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kfree(udev->serial);
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kfree(udev);
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}
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struct device_type usb_device_type = {
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.name = "usb_device",
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.release = usb_release_dev,
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};
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#ifdef CONFIG_PM
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static int ksuspend_usb_init(void)
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{
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/* This workqueue is supposed to be both freezable and
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* singlethreaded. Its job doesn't justify running on more
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* than one CPU.
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*/
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ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd");
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if (!ksuspend_usb_wq)
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return -ENOMEM;
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return 0;
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}
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static void ksuspend_usb_cleanup(void)
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{
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destroy_workqueue(ksuspend_usb_wq);
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}
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#else
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#define ksuspend_usb_init() 0
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#define ksuspend_usb_cleanup() do {} while (0)
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#endif /* CONFIG_PM */
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/**
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* usb_alloc_dev - usb device constructor (usbcore-internal)
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* @parent: hub to which device is connected; null to allocate a root hub
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* @bus: bus used to access the device
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* @port1: one-based index of port; ignored for root hubs
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* Context: !in_interrupt()
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*
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* Only hub drivers (including virtual root hub drivers for host
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* controllers) should ever call this.
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*
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* This call may not be used in a non-sleeping context.
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*/
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struct usb_device *
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usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1)
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{
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struct usb_device *dev;
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dev = kzalloc(sizeof(*dev), GFP_KERNEL);
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if (!dev)
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return NULL;
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if (!usb_get_hcd(bus_to_hcd(bus))) {
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kfree(dev);
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return NULL;
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}
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device_initialize(&dev->dev);
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dev->dev.bus = &usb_bus_type;
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dev->dev.type = &usb_device_type;
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dev->dev.dma_mask = bus->controller->dma_mask;
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set_dev_node(&dev->dev, dev_to_node(bus->controller));
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dev->state = USB_STATE_ATTACHED;
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INIT_LIST_HEAD(&dev->ep0.urb_list);
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dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
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dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
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/* ep0 maxpacket comes later, from device descriptor */
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dev->ep_in[0] = dev->ep_out[0] = &dev->ep0;
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/* Save readable and stable topology id, distinguishing devices
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* by location for diagnostics, tools, driver model, etc. The
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* string is a path along hub ports, from the root. Each device's
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* dev->devpath will be stable until USB is re-cabled, and hubs
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* are often labeled with these port numbers. The bus_id isn't
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* as stable: bus->busnum changes easily from modprobe order,
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* cardbus or pci hotplugging, and so on.
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*/
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if (unlikely(!parent)) {
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dev->devpath[0] = '0';
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dev->dev.parent = bus->controller;
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sprintf(&dev->dev.bus_id[0], "usb%d", bus->busnum);
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} else {
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/* match any labeling on the hubs; it's one-based */
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if (parent->devpath[0] == '0')
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snprintf(dev->devpath, sizeof dev->devpath,
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"%d", port1);
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else
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snprintf(dev->devpath, sizeof dev->devpath,
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"%s.%d", parent->devpath, port1);
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dev->dev.parent = &parent->dev;
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sprintf(&dev->dev.bus_id[0], "%d-%s",
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bus->busnum, dev->devpath);
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/* hub driver sets up TT records */
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}
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dev->portnum = port1;
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dev->bus = bus;
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dev->parent = parent;
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INIT_LIST_HEAD(&dev->filelist);
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#ifdef CONFIG_PM
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mutex_init(&dev->pm_mutex);
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INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);
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dev->autosuspend_delay = usb_autosuspend_delay * HZ;
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#endif
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return dev;
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}
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/**
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* usb_get_dev - increments the reference count of the usb device structure
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* @dev: the device being referenced
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*
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* Each live reference to a device should be refcounted.
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*
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* Drivers for USB interfaces should normally record such references in
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* their probe() methods, when they bind to an interface, and release
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* them by calling usb_put_dev(), in their disconnect() methods.
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*
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* A pointer to the device with the incremented reference counter is returned.
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*/
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struct usb_device *usb_get_dev(struct usb_device *dev)
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{
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if (dev)
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get_device(&dev->dev);
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return dev;
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}
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/**
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* usb_put_dev - release a use of the usb device structure
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* @dev: device that's been disconnected
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*
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* Must be called when a user of a device is finished with it. When the last
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* user of the device calls this function, the memory of the device is freed.
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*/
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void usb_put_dev(struct usb_device *dev)
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{
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if (dev)
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put_device(&dev->dev);
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}
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/**
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* usb_get_intf - increments the reference count of the usb interface structure
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* @intf: the interface being referenced
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*
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* Each live reference to a interface must be refcounted.
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*
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* Drivers for USB interfaces should normally record such references in
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* their probe() methods, when they bind to an interface, and release
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* them by calling usb_put_intf(), in their disconnect() methods.
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*
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* A pointer to the interface with the incremented reference counter is
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* returned.
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*/
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struct usb_interface *usb_get_intf(struct usb_interface *intf)
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{
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if (intf)
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get_device(&intf->dev);
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return intf;
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}
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/**
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* usb_put_intf - release a use of the usb interface structure
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* @intf: interface that's been decremented
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*
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* Must be called when a user of an interface is finished with it. When the
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* last user of the interface calls this function, the memory of the interface
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* is freed.
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*/
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void usb_put_intf(struct usb_interface *intf)
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{
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if (intf)
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put_device(&intf->dev);
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}
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/* USB device locking
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*
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* USB devices and interfaces are locked using the semaphore in their
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* embedded struct device. The hub driver guarantees that whenever a
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* device is connected or disconnected, drivers are called with the
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* USB device locked as well as their particular interface.
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*
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* Complications arise when several devices are to be locked at the same
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* time. Only hub-aware drivers that are part of usbcore ever have to
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* do this; nobody else needs to worry about it. The rule for locking
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* is simple:
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*
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* When locking both a device and its parent, always lock the
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* the parent first.
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*/
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/**
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* usb_lock_device_for_reset - cautiously acquire the lock for a
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* usb device structure
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* @udev: device that's being locked
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* @iface: interface bound to the driver making the request (optional)
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*
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* Attempts to acquire the device lock, but fails if the device is
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* NOTATTACHED or SUSPENDED, or if iface is specified and the interface
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* is neither BINDING nor BOUND. Rather than sleeping to wait for the
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* lock, the routine polls repeatedly. This is to prevent deadlock with
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* disconnect; in some drivers (such as usb-storage) the disconnect()
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* or suspend() method will block waiting for a device reset to complete.
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*
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* Returns a negative error code for failure, otherwise 1 or 0 to indicate
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* that the device will or will not have to be unlocked. (0 can be
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* returned when an interface is given and is BINDING, because in that
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* case the driver already owns the device lock.)
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*/
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int usb_lock_device_for_reset(struct usb_device *udev,
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const struct usb_interface *iface)
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{
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unsigned long jiffies_expire = jiffies + HZ;
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if (udev->state == USB_STATE_NOTATTACHED)
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return -ENODEV;
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if (udev->state == USB_STATE_SUSPENDED)
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return -EHOSTUNREACH;
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if (iface) {
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switch (iface->condition) {
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case USB_INTERFACE_BINDING:
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return 0;
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case USB_INTERFACE_BOUND:
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break;
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default:
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return -EINTR;
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}
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}
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while (usb_trylock_device(udev) != 0) {
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|
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/* If we can't acquire the lock after waiting one second,
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* we're probably deadlocked */
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if (time_after(jiffies, jiffies_expire))
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return -EBUSY;
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msleep(15);
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if (udev->state == USB_STATE_NOTATTACHED)
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return -ENODEV;
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if (udev->state == USB_STATE_SUSPENDED)
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return -EHOSTUNREACH;
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if (iface && iface->condition != USB_INTERFACE_BOUND)
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return -EINTR;
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}
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return 1;
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}
|
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|
|
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static struct usb_device *match_device(struct usb_device *dev,
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u16 vendor_id, u16 product_id)
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{
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struct usb_device *ret_dev = NULL;
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int child;
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dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n",
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le16_to_cpu(dev->descriptor.idVendor),
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le16_to_cpu(dev->descriptor.idProduct));
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|
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/* see if this device matches */
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if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) &&
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(product_id == le16_to_cpu(dev->descriptor.idProduct))) {
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dev_dbg(&dev->dev, "matched this device!\n");
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ret_dev = usb_get_dev(dev);
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goto exit;
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}
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|
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/* look through all of the children of this device */
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for (child = 0; child < dev->maxchild; ++child) {
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if (dev->children[child]) {
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usb_lock_device(dev->children[child]);
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ret_dev = match_device(dev->children[child],
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vendor_id, product_id);
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usb_unlock_device(dev->children[child]);
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if (ret_dev)
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goto exit;
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}
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}
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exit:
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return ret_dev;
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}
|
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|
|
/**
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|
* usb_find_device - find a specific usb device in the system
|
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* @vendor_id: the vendor id of the device to find
|
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* @product_id: the product id of the device to find
|
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*
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* Returns a pointer to a struct usb_device if such a specified usb
|
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* device is present in the system currently. The usage count of the
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* device will be incremented if a device is found. Make sure to call
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* usb_put_dev() when the caller is finished with the device.
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*
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* If a device with the specified vendor and product id is not found,
|
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* NULL is returned.
|
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*/
|
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struct usb_device *usb_find_device(u16 vendor_id, u16 product_id)
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{
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struct list_head *buslist;
|
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struct usb_bus *bus;
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struct usb_device *dev = NULL;
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|
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mutex_lock(&usb_bus_list_lock);
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for (buslist = usb_bus_list.next;
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buslist != &usb_bus_list;
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buslist = buslist->next) {
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bus = container_of(buslist, struct usb_bus, bus_list);
|
|
if (!bus->root_hub)
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continue;
|
|
usb_lock_device(bus->root_hub);
|
|
dev = match_device(bus->root_hub, vendor_id, product_id);
|
|
usb_unlock_device(bus->root_hub);
|
|
if (dev)
|
|
goto exit;
|
|
}
|
|
exit:
|
|
mutex_unlock(&usb_bus_list_lock);
|
|
return dev;
|
|
}
|
|
|
|
/**
|
|
* usb_get_current_frame_number - return current bus frame number
|
|
* @dev: the device whose bus is being queried
|
|
*
|
|
* Returns the current frame number for the USB host controller
|
|
* used with the given USB device. This can be used when scheduling
|
|
* isochronous requests.
|
|
*
|
|
* Note that different kinds of host controller have different
|
|
* "scheduling horizons". While one type might support scheduling only
|
|
* 32 frames into the future, others could support scheduling up to
|
|
* 1024 frames into the future.
|
|
*/
|
|
int usb_get_current_frame_number(struct usb_device *dev)
|
|
{
|
|
return usb_hcd_get_frame_number(dev);
|
|
}
|
|
|
|
/*-------------------------------------------------------------------*/
|
|
/*
|
|
* __usb_get_extra_descriptor() finds a descriptor of specific type in the
|
|
* extra field of the interface and endpoint descriptor structs.
|
|
*/
|
|
|
|
int __usb_get_extra_descriptor(char *buffer, unsigned size,
|
|
unsigned char type, void **ptr)
|
|
{
|
|
struct usb_descriptor_header *header;
|
|
|
|
while (size >= sizeof(struct usb_descriptor_header)) {
|
|
header = (struct usb_descriptor_header *)buffer;
|
|
|
|
if (header->bLength < 2) {
|
|
printk(KERN_ERR
|
|
"%s: bogus descriptor, type %d length %d\n",
|
|
usbcore_name,
|
|
header->bDescriptorType,
|
|
header->bLength);
|
|
return -1;
|
|
}
|
|
|
|
if (header->bDescriptorType == type) {
|
|
*ptr = header;
|
|
return 0;
|
|
}
|
|
|
|
buffer += header->bLength;
|
|
size -= header->bLength;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
|
|
* @dev: device the buffer will be used with
|
|
* @size: requested buffer size
|
|
* @mem_flags: affect whether allocation may block
|
|
* @dma: used to return DMA address of buffer
|
|
*
|
|
* Return value is either null (indicating no buffer could be allocated), or
|
|
* the cpu-space pointer to a buffer that may be used to perform DMA to the
|
|
* specified device. Such cpu-space buffers are returned along with the DMA
|
|
* address (through the pointer provided).
|
|
*
|
|
* These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
|
|
* to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
|
|
* hardware during URB completion/resubmit. The implementation varies between
|
|
* platforms, depending on details of how DMA will work to this device.
|
|
* Using these buffers also eliminates cacheline sharing problems on
|
|
* architectures where CPU caches are not DMA-coherent. On systems without
|
|
* bus-snooping caches, these buffers are uncached.
|
|
*
|
|
* When the buffer is no longer used, free it with usb_buffer_free().
|
|
*/
|
|
void *usb_buffer_alloc(
|
|
struct usb_device *dev,
|
|
size_t size,
|
|
gfp_t mem_flags,
|
|
dma_addr_t *dma
|
|
)
|
|
{
|
|
if (!dev || !dev->bus)
|
|
return NULL;
|
|
return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
|
|
}
|
|
|
|
/**
|
|
* usb_buffer_free - free memory allocated with usb_buffer_alloc()
|
|
* @dev: device the buffer was used with
|
|
* @size: requested buffer size
|
|
* @addr: CPU address of buffer
|
|
* @dma: DMA address of buffer
|
|
*
|
|
* This reclaims an I/O buffer, letting it be reused. The memory must have
|
|
* been allocated using usb_buffer_alloc(), and the parameters must match
|
|
* those provided in that allocation request.
|
|
*/
|
|
void usb_buffer_free(
|
|
struct usb_device *dev,
|
|
size_t size,
|
|
void *addr,
|
|
dma_addr_t dma
|
|
)
|
|
{
|
|
if (!dev || !dev->bus)
|
|
return;
|
|
if (!addr)
|
|
return;
|
|
hcd_buffer_free(dev->bus, size, addr, dma);
|
|
}
|
|
|
|
/**
|
|
* usb_buffer_map - create DMA mapping(s) for an urb
|
|
* @urb: urb whose transfer_buffer/setup_packet will be mapped
|
|
*
|
|
* Return value is either null (indicating no buffer could be mapped), or
|
|
* the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
|
|
* added to urb->transfer_flags if the operation succeeds. If the device
|
|
* is connected to this system through a non-DMA controller, this operation
|
|
* always succeeds.
|
|
*
|
|
* This call would normally be used for an urb which is reused, perhaps
|
|
* as the target of a large periodic transfer, with usb_buffer_dmasync()
|
|
* calls to synchronize memory and dma state.
|
|
*
|
|
* Reverse the effect of this call with usb_buffer_unmap().
|
|
*/
|
|
#if 0
|
|
struct urb *usb_buffer_map(struct urb *urb)
|
|
{
|
|
struct usb_bus *bus;
|
|
struct device *controller;
|
|
|
|
if (!urb
|
|
|| !urb->dev
|
|
|| !(bus = urb->dev->bus)
|
|
|| !(controller = bus->controller))
|
|
return NULL;
|
|
|
|
if (controller->dma_mask) {
|
|
urb->transfer_dma = dma_map_single(controller,
|
|
urb->transfer_buffer, urb->transfer_buffer_length,
|
|
usb_pipein(urb->pipe)
|
|
? DMA_FROM_DEVICE : DMA_TO_DEVICE);
|
|
if (usb_pipecontrol(urb->pipe))
|
|
urb->setup_dma = dma_map_single(controller,
|
|
urb->setup_packet,
|
|
sizeof(struct usb_ctrlrequest),
|
|
DMA_TO_DEVICE);
|
|
// FIXME generic api broken like pci, can't report errors
|
|
// if (urb->transfer_dma == DMA_ADDR_INVALID) return 0;
|
|
} else
|
|
urb->transfer_dma = ~0;
|
|
urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP
|
|
| URB_NO_SETUP_DMA_MAP);
|
|
return urb;
|
|
}
|
|
#endif /* 0 */
|
|
|
|
/* XXX DISABLED, no users currently. If you wish to re-enable this
|
|
* XXX please determine whether the sync is to transfer ownership of
|
|
* XXX the buffer from device to cpu or vice verse, and thusly use the
|
|
* XXX appropriate _for_{cpu,device}() method. -DaveM
|
|
*/
|
|
#if 0
|
|
|
|
/**
|
|
* usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
|
|
* @urb: urb whose transfer_buffer/setup_packet will be synchronized
|
|
*/
|
|
void usb_buffer_dmasync(struct urb *urb)
|
|
{
|
|
struct usb_bus *bus;
|
|
struct device *controller;
|
|
|
|
if (!urb
|
|
|| !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
|
|
|| !urb->dev
|
|
|| !(bus = urb->dev->bus)
|
|
|| !(controller = bus->controller))
|
|
return;
|
|
|
|
if (controller->dma_mask) {
|
|
dma_sync_single(controller,
|
|
urb->transfer_dma, urb->transfer_buffer_length,
|
|
usb_pipein(urb->pipe)
|
|
? DMA_FROM_DEVICE : DMA_TO_DEVICE);
|
|
if (usb_pipecontrol(urb->pipe))
|
|
dma_sync_single(controller,
|
|
urb->setup_dma,
|
|
sizeof(struct usb_ctrlrequest),
|
|
DMA_TO_DEVICE);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* usb_buffer_unmap - free DMA mapping(s) for an urb
|
|
* @urb: urb whose transfer_buffer will be unmapped
|
|
*
|
|
* Reverses the effect of usb_buffer_map().
|
|
*/
|
|
#if 0
|
|
void usb_buffer_unmap(struct urb *urb)
|
|
{
|
|
struct usb_bus *bus;
|
|
struct device *controller;
|
|
|
|
if (!urb
|
|
|| !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
|
|
|| !urb->dev
|
|
|| !(bus = urb->dev->bus)
|
|
|| !(controller = bus->controller))
|
|
return;
|
|
|
|
if (controller->dma_mask) {
|
|
dma_unmap_single(controller,
|
|
urb->transfer_dma, urb->transfer_buffer_length,
|
|
usb_pipein(urb->pipe)
|
|
? DMA_FROM_DEVICE : DMA_TO_DEVICE);
|
|
if (usb_pipecontrol(urb->pipe))
|
|
dma_unmap_single(controller,
|
|
urb->setup_dma,
|
|
sizeof(struct usb_ctrlrequest),
|
|
DMA_TO_DEVICE);
|
|
}
|
|
urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP
|
|
| URB_NO_SETUP_DMA_MAP);
|
|
}
|
|
#endif /* 0 */
|
|
|
|
/**
|
|
* usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
|
|
* @dev: device to which the scatterlist will be mapped
|
|
* @pipe: endpoint defining the mapping direction
|
|
* @sg: the scatterlist to map
|
|
* @nents: the number of entries in the scatterlist
|
|
*
|
|
* Return value is either < 0 (indicating no buffers could be mapped), or
|
|
* the number of DMA mapping array entries in the scatterlist.
|
|
*
|
|
* The caller is responsible for placing the resulting DMA addresses from
|
|
* the scatterlist into URB transfer buffer pointers, and for setting the
|
|
* URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
|
|
*
|
|
* Top I/O rates come from queuing URBs, instead of waiting for each one
|
|
* to complete before starting the next I/O. This is particularly easy
|
|
* to do with scatterlists. Just allocate and submit one URB for each DMA
|
|
* mapping entry returned, stopping on the first error or when all succeed.
|
|
* Better yet, use the usb_sg_*() calls, which do that (and more) for you.
|
|
*
|
|
* This call would normally be used when translating scatterlist requests,
|
|
* rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
|
|
* may be able to coalesce mappings for improved I/O efficiency.
|
|
*
|
|
* Reverse the effect of this call with usb_buffer_unmap_sg().
|
|
*/
|
|
int usb_buffer_map_sg(const struct usb_device *dev, unsigned pipe,
|
|
struct scatterlist *sg, int nents)
|
|
{
|
|
struct usb_bus *bus;
|
|
struct device *controller;
|
|
|
|
if (!dev
|
|
|| usb_pipecontrol(pipe)
|
|
|| !(bus = dev->bus)
|
|
|| !(controller = bus->controller)
|
|
|| !controller->dma_mask)
|
|
return -1;
|
|
|
|
// FIXME generic api broken like pci, can't report errors
|
|
return dma_map_sg(controller, sg, nents,
|
|
usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
|
|
}
|
|
|
|
/* XXX DISABLED, no users currently. If you wish to re-enable this
|
|
* XXX please determine whether the sync is to transfer ownership of
|
|
* XXX the buffer from device to cpu or vice verse, and thusly use the
|
|
* XXX appropriate _for_{cpu,device}() method. -DaveM
|
|
*/
|
|
#if 0
|
|
|
|
/**
|
|
* usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
|
|
* @dev: device to which the scatterlist will be mapped
|
|
* @pipe: endpoint defining the mapping direction
|
|
* @sg: the scatterlist to synchronize
|
|
* @n_hw_ents: the positive return value from usb_buffer_map_sg
|
|
*
|
|
* Use this when you are re-using a scatterlist's data buffers for
|
|
* another USB request.
|
|
*/
|
|
void usb_buffer_dmasync_sg(const struct usb_device *dev, unsigned pipe,
|
|
struct scatterlist *sg, int n_hw_ents)
|
|
{
|
|
struct usb_bus *bus;
|
|
struct device *controller;
|
|
|
|
if (!dev
|
|
|| !(bus = dev->bus)
|
|
|| !(controller = bus->controller)
|
|
|| !controller->dma_mask)
|
|
return;
|
|
|
|
dma_sync_sg(controller, sg, n_hw_ents,
|
|
usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
|
|
* @dev: device to which the scatterlist will be mapped
|
|
* @pipe: endpoint defining the mapping direction
|
|
* @sg: the scatterlist to unmap
|
|
* @n_hw_ents: the positive return value from usb_buffer_map_sg
|
|
*
|
|
* Reverses the effect of usb_buffer_map_sg().
|
|
*/
|
|
void usb_buffer_unmap_sg(const struct usb_device *dev, unsigned pipe,
|
|
struct scatterlist *sg, int n_hw_ents)
|
|
{
|
|
struct usb_bus *bus;
|
|
struct device *controller;
|
|
|
|
if (!dev
|
|
|| !(bus = dev->bus)
|
|
|| !(controller = bus->controller)
|
|
|| !controller->dma_mask)
|
|
return;
|
|
|
|
dma_unmap_sg(controller, sg, n_hw_ents,
|
|
usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
|
|
}
|
|
|
|
/* format to disable USB on kernel command line is: nousb */
|
|
__module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444);
|
|
|
|
/*
|
|
* for external read access to <nousb>
|
|
*/
|
|
int usb_disabled(void)
|
|
{
|
|
return nousb;
|
|
}
|
|
|
|
/*
|
|
* Init
|
|
*/
|
|
static int __init usb_init(void)
|
|
{
|
|
int retval;
|
|
if (nousb) {
|
|
pr_info("%s: USB support disabled\n", usbcore_name);
|
|
return 0;
|
|
}
|
|
|
|
retval = ksuspend_usb_init();
|
|
if (retval)
|
|
goto out;
|
|
retval = bus_register(&usb_bus_type);
|
|
if (retval)
|
|
goto bus_register_failed;
|
|
retval = usb_host_init();
|
|
if (retval)
|
|
goto host_init_failed;
|
|
retval = usb_major_init();
|
|
if (retval)
|
|
goto major_init_failed;
|
|
retval = usb_register(&usbfs_driver);
|
|
if (retval)
|
|
goto driver_register_failed;
|
|
retval = usb_devio_init();
|
|
if (retval)
|
|
goto usb_devio_init_failed;
|
|
retval = usbfs_init();
|
|
if (retval)
|
|
goto fs_init_failed;
|
|
retval = usb_hub_init();
|
|
if (retval)
|
|
goto hub_init_failed;
|
|
retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
|
|
if (!retval)
|
|
goto out;
|
|
|
|
usb_hub_cleanup();
|
|
hub_init_failed:
|
|
usbfs_cleanup();
|
|
fs_init_failed:
|
|
usb_devio_cleanup();
|
|
usb_devio_init_failed:
|
|
usb_deregister(&usbfs_driver);
|
|
driver_register_failed:
|
|
usb_major_cleanup();
|
|
major_init_failed:
|
|
usb_host_cleanup();
|
|
host_init_failed:
|
|
bus_unregister(&usb_bus_type);
|
|
bus_register_failed:
|
|
ksuspend_usb_cleanup();
|
|
out:
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Cleanup
|
|
*/
|
|
static void __exit usb_exit(void)
|
|
{
|
|
/* This will matter if shutdown/reboot does exitcalls. */
|
|
if (nousb)
|
|
return;
|
|
|
|
usb_deregister_device_driver(&usb_generic_driver);
|
|
usb_major_cleanup();
|
|
usbfs_cleanup();
|
|
usb_deregister(&usbfs_driver);
|
|
usb_devio_cleanup();
|
|
usb_hub_cleanup();
|
|
usb_host_cleanup();
|
|
bus_unregister(&usb_bus_type);
|
|
ksuspend_usb_cleanup();
|
|
}
|
|
|
|
subsys_initcall(usb_init);
|
|
module_exit(usb_exit);
|
|
|
|
/*
|
|
* USB may be built into the kernel or be built as modules.
|
|
* These symbols are exported for device (or host controller)
|
|
* driver modules to use.
|
|
*/
|
|
|
|
EXPORT_SYMBOL(usb_disabled);
|
|
|
|
EXPORT_SYMBOL_GPL(usb_get_intf);
|
|
EXPORT_SYMBOL_GPL(usb_put_intf);
|
|
|
|
EXPORT_SYMBOL(usb_put_dev);
|
|
EXPORT_SYMBOL(usb_get_dev);
|
|
EXPORT_SYMBOL(usb_hub_tt_clear_buffer);
|
|
|
|
EXPORT_SYMBOL(usb_lock_device_for_reset);
|
|
|
|
EXPORT_SYMBOL(usb_find_interface);
|
|
EXPORT_SYMBOL(usb_ifnum_to_if);
|
|
EXPORT_SYMBOL(usb_altnum_to_altsetting);
|
|
|
|
EXPORT_SYMBOL(__usb_get_extra_descriptor);
|
|
|
|
EXPORT_SYMBOL(usb_find_device);
|
|
EXPORT_SYMBOL(usb_get_current_frame_number);
|
|
|
|
EXPORT_SYMBOL(usb_buffer_alloc);
|
|
EXPORT_SYMBOL(usb_buffer_free);
|
|
|
|
#if 0
|
|
EXPORT_SYMBOL(usb_buffer_map);
|
|
EXPORT_SYMBOL(usb_buffer_dmasync);
|
|
EXPORT_SYMBOL(usb_buffer_unmap);
|
|
#endif
|
|
|
|
EXPORT_SYMBOL(usb_buffer_map_sg);
|
|
#if 0
|
|
EXPORT_SYMBOL(usb_buffer_dmasync_sg);
|
|
#endif
|
|
EXPORT_SYMBOL(usb_buffer_unmap_sg);
|
|
|
|
MODULE_LICENSE("GPL");
|