1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
|
/*
* 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
*
*/
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include "usb.h"
static inline const char *plural(int n)
{
return (n == 1 ? "" : "s");
}
static int is_rndis(struct usb_interface_descriptor *desc)
{
return desc->bInterfaceClass == USB_CLASS_COMM
&& desc->bInterfaceSubClass == 2
&& desc->bInterfaceProtocol == 0xff;
}
static int is_activesync(struct usb_interface_descriptor *desc)
{
return desc->bInterfaceClass == USB_CLASS_MISC
&& desc->bInterfaceSubClass == 1
&& desc->bInterfaceProtocol == 1;
}
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;
}
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;
}
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);
}
#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;
}
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;
}
#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,
};
|
