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Release 4.11 drivers/usb/core/generic.c

Directory: drivers/usb/core
/*
 * drivers/usb/generic.c - generic driver for USB devices (not interfaces)
 *
 * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
 *
 * based on drivers/usb/usb.c which had the following copyrights:
 *      (C) Copyright Linus Torvalds 1999
 *      (C) Copyright Johannes Erdfelt 1999-2001
 *      (C) Copyright Andreas Gal 1999
 *      (C) Copyright Gregory P. Smith 1999
 *      (C) Copyright Deti Fliegl 1999 (new USB architecture)
 *      (C) Copyright Randy Dunlap 2000
 *      (C) Copyright David Brownell 2000-2004
 *      (C) Copyright Yggdrasil Computing, Inc. 2000
 *              (usb_device_id matching changes by Adam J. Richter)
 *      (C) Copyright Greg Kroah-Hartman 2002-2003
 *
 * Released under the GPLv2 only.
 * SPDX-License-Identifier: GPL-2.0
 */

#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include "usb.h"


static inline const char *plural(int n) { return (n == 1 ? "" : "s"); }

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PersonTokensPropCommitsCommitProp
Alan Stern23100.00%1100.00%
Total23100.00%1100.00%


static int is_rndis(struct usb_interface_descriptor *desc) { return desc->bInterfaceClass == USB_CLASS_COMM && desc->bInterfaceSubClass == 2 && desc->bInterfaceProtocol == 0xff; }

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Ole Andre Vadla Ravnas30100.00%1100.00%
Total30100.00%1100.00%


static int is_activesync(struct usb_interface_descriptor *desc) { return desc->bInterfaceClass == USB_CLASS_MISC && desc->bInterfaceSubClass == 1 && desc->bInterfaceProtocol == 1; }

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PersonTokensPropCommitsCommitProp
Ole Andre Vadla Ravnas30100.00%1100.00%
Total30100.00%1100.00%


int usb_choose_configuration(struct usb_device *udev) { int i; int num_configs; int insufficient_power = 0; struct usb_host_config *c, *best; if (usb_device_is_owned(udev)) return 0; best = NULL; c = udev->config; num_configs = udev->descriptor.bNumConfigurations; for (i = 0; i < num_configs; (i++, c++)) { struct usb_interface_descriptor *desc = NULL; /* It's possible that a config has no interfaces! */ if (c->desc.bNumInterfaces > 0) desc = &c->intf_cache[0]->altsetting->desc; /* * HP's USB bus-powered keyboard has only one configuration * and it claims to be self-powered; other devices may have * similar errors in their descriptors. If the next test * were allowed to execute, such configurations would always * be rejected and the devices would not work as expected. * In the meantime, we run the risk of selecting a config * that requires external power at a time when that power * isn't available. It seems to be the lesser of two evils. * * Bugzilla #6448 reports a device that appears to crash * when it receives a GET_DEVICE_STATUS request! We don't * have any other way to tell whether a device is self-powered, * but since we don't use that information anywhere but here, * the call has been removed. * * Maybe the GET_DEVICE_STATUS call and the test below can * be reinstated when device firmwares become more reliable. * Don't hold your breath. */ #if 0 /* Rule out self-powered configs for a bus-powered device */ if (bus_powered && (c->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)) continue; #endif /* * The next test may not be as effective as it should be. * Some hubs have errors in their descriptor, claiming * to be self-powered when they are really bus-powered. * We will overestimate the amount of current such hubs * make available for each port. * * This is a fairly benign sort of failure. It won't * cause us to reject configurations that we should have * accepted. */ /* Rule out configs that draw too much bus current */ if (usb_get_max_power(udev, c) > udev->bus_mA) { insufficient_power++; continue; } /* When the first config's first interface is one of Microsoft's * pet nonstandard Ethernet-over-USB protocols, ignore it unless * this kernel has enabled the necessary host side driver. * But: Don't ignore it if it's the only config. */ if (i == 0 && num_configs > 1 && desc && (is_rndis(desc) || is_activesync(desc))) { #if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE) continue; #else best = c; #endif } /* From the remaining configs, choose the first one whose * first interface is for a non-vendor-specific class. * Reason: Linux is more likely to have a class driver * than a vendor-specific driver. */ else if (udev->descriptor.bDeviceClass != USB_CLASS_VENDOR_SPEC && (desc && desc->bInterfaceClass != USB_CLASS_VENDOR_SPEC)) { best = c; break; } /* If all the remaining configs are vendor-specific, * choose the first one. */ else if (!best) best = c; } if (insufficient_power > 0) dev_info(&udev->dev, "rejected %d configuration%s " "due to insufficient available bus power\n", insufficient_power, plural(insufficient_power)); if (best) { i = best->desc.bConfigurationValue; dev_dbg(&udev->dev, "configuration #%d chosen from %d choice%s\n", i, num_configs, plural(num_configs)); } else { i = -1; dev_warn(&udev->dev, "no configuration chosen from %d choice%s\n", num_configs, plural(num_configs)); } return i; }

Contributors

PersonTokensPropCommitsCommitProp
Alan Stern27487.82%337.50%
Ole Andre Vadla Ravnas216.73%112.50%
Hindin Joseph103.21%112.50%
Sebastian Andrzej Siewior51.60%112.50%
Greg Kroah-Hartman10.32%112.50%
Matthew Wilcox10.32%112.50%
Total312100.00%8100.00%

EXPORT_SYMBOL_GPL(usb_choose_configuration);
static int generic_probe(struct usb_device *udev) { int err, c; /* Choose and set the configuration. This registers the interfaces * with the driver core and lets interface drivers bind to them. */ if (udev->authorized == 0) dev_err(&udev->dev, "Device is not authorized for usage\n"); else { c = usb_choose_configuration(udev); if (c >= 0) { err = usb_set_configuration(udev, c); if (err && err != -ENODEV) { dev_err(&udev->dev, "can't set config #%d, error %d\n", c, err); /* This need not be fatal. The user can try to * set other configurations. */ } } } /* USB device state == configured ... usable */ usb_notify_add_device(udev); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Alan Stern7476.29%466.67%
Iñaky Pérez-González2222.68%116.67%
Greg Kroah-Hartman11.03%116.67%
Total97100.00%6100.00%


static void generic_disconnect(struct usb_device *udev) { usb_notify_remove_device(udev); /* if this is only an unbind, not a physical disconnect, then * unconfigure the device */ if (udev->actconfig) usb_set_configuration(udev, -1); }

Contributors

PersonTokensPropCommitsCommitProp
Alan Stern31100.00%5100.00%
Total31100.00%5100.00%

#ifdef CONFIG_PM
static int generic_suspend(struct usb_device *udev, pm_message_t msg) { int rc; /* Normal USB devices suspend through their upstream port. * Root hubs don't have upstream ports to suspend, * so we have to shut down their downstream HC-to-USB * interfaces manually by doing a bus (or "global") suspend. */ if (!udev->parent) rc = hcd_bus_suspend(udev, msg); /* Non-root devices don't need to do anything for FREEZE or PRETHAW */ else if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW) rc = 0; else rc = usb_port_suspend(udev, msg); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Alan Stern67100.00%5100.00%
Total67100.00%5100.00%


static int generic_resume(struct usb_device *udev, pm_message_t msg) { int rc; /* Normal USB devices resume/reset through their upstream port. * Root hubs don't have upstream ports to resume or reset, * so we have to start up their downstream HC-to-USB * interfaces manually by doing a bus (or "global") resume. */ if (!udev->parent) rc = hcd_bus_resume(udev, msg); else rc = usb_port_resume(udev, msg); return rc; }

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PersonTokensPropCommitsCommitProp
Alan Stern47100.00%5100.00%
Total47100.00%5100.00%

#endif /* CONFIG_PM */ struct usb_device_driver usb_generic_driver = { .name = "usb", .probe = generic_probe, .disconnect = generic_disconnect, #ifdef CONFIG_PM .suspend = generic_suspend, .resume = generic_resume, #endif .supports_autosuspend = 1, };

Overall Contributors

PersonTokensPropCommitsCommitProp
Alan Stern57081.55%1359.09%
Ole Andre Vadla Ravnas8111.59%14.55%
Iñaky Pérez-González223.15%14.55%
Hindin Joseph101.43%14.55%
Sebastian Andrzej Siewior50.72%14.55%
Valentina Manea50.72%14.55%
Greg Kroah-Hartman30.43%29.09%
Eric Lescouet20.29%14.55%
Matthew Wilcox10.14%14.55%
Total699100.00%22100.00%
Directory: drivers/usb/core
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