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1da177e4 LT |
1 | # |
2 | # USB Core configuration | |
3 | # | |
4 | config USB_DEBUG | |
5 | bool "USB verbose debug messages" | |
6 | depends on USB | |
7 | help | |
8 | Say Y here if you want the USB core & hub drivers to produce a bunch | |
9 | of debug messages to the system log. Select this if you are having a | |
10 | problem with USB support and want to see more of what is going on. | |
11 | ||
12 | comment "Miscellaneous USB options" | |
13 | depends on USB | |
14 | ||
15 | config USB_DEVICEFS | |
16 | bool "USB device filesystem" | |
17 | depends on USB | |
18 | ---help--- | |
19 | If you say Y here (and to "/proc file system support" in the "File | |
20 | systems" section, above), you will get a file /proc/bus/usb/devices | |
21 | which lists the devices currently connected to your USB bus or | |
22 | busses, and for every connected device a file named | |
23 | "/proc/bus/usb/xxx/yyy", where xxx is the bus number and yyy the | |
24 | device number; the latter files can be used by user space programs | |
25 | to talk directly to the device. These files are "virtual", meaning | |
26 | they are generated on the fly and not stored on the hard drive. | |
27 | ||
28 | You may need to mount the usbfs file system to see the files, use | |
29 | mount -t usbfs none /proc/bus/usb | |
30 | ||
31 | For the format of the various /proc/bus/usb/ files, please read | |
32 | <file:Documentation/usb/proc_usb_info.txt>. | |
33 | ||
9f8b17e6 KS |
34 | Usbfs files can't handle Access Control Lists (ACL), which are the |
35 | default way to grant access to USB devices for untrusted users of a | |
36 | desktop system. The usbfs functionality is replaced by real | |
37 | device-nodes managed by udev. These nodes live in /dev/bus/usb and | |
38 | are used by libusb. | |
39 | ||
40 | config USB_DEVICE_CLASS | |
41 | bool "USB device class-devices (DEPRECATED)" | |
42 | depends on USB | |
dda034bc | 43 | default y |
9f8b17e6 KS |
44 | ---help--- |
45 | Userspace access to USB devices is granted by device-nodes exported | |
46 | directly from the usbdev in sysfs. Old versions of the driver | |
47 | core and udev needed additional class devices to export device nodes. | |
48 | ||
49 | These additional devices are difficult to handle in userspace, if | |
dda034bc KS |
50 | information about USB interfaces must be available. One device |
51 | contains the device node, the other device contains the interface | |
52 | data. Both devices are at the same level in sysfs (siblings) and one | |
53 | can't access the other. The device node created directly by the | |
54 | usb device is the parent device of the interface and therefore | |
55 | easily accessible from the interface event. | |
9f8b17e6 | 56 | |
dda034bc KS |
57 | This option provides backward compatibility for libusb device |
58 | nodes (lsusb) when usbfs is not used, and the following udev rule | |
59 | doesn't exist: | |
60 | SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \ | |
61 | NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644" | |
1da177e4 | 62 | |
1da177e4 LT |
63 | config USB_DYNAMIC_MINORS |
64 | bool "Dynamic USB minor allocation (EXPERIMENTAL)" | |
65 | depends on USB && EXPERIMENTAL | |
66 | help | |
67 | If you say Y here, the USB subsystem will use dynamic minor | |
68 | allocation for any device that uses the USB major number. | |
69 | This means that you can have more than 16 of a single type | |
70 | of device (like USB printers). | |
71 | ||
72 | If you are unsure about this, say N here. | |
73 | ||
74 | config USB_SUSPEND | |
f3f3253d | 75 | bool "USB selective suspend/resume and wakeup (EXPERIMENTAL)" |
1da177e4 LT |
76 | depends on USB && PM && EXPERIMENTAL |
77 | help | |
78 | If you say Y here, you can use driver calls or the sysfs | |
79 | "power/state" file to suspend or resume individual USB | |
f3f3253d DB |
80 | peripherals. |
81 | ||
82 | Also, USB "remote wakeup" signaling is supported, whereby some | |
83 | USB devices (like keyboards and network adapters) can wake up | |
84 | their parent hub. That wakeup cascades up the USB tree, and | |
85 | could wake the system from states like suspend-to-RAM. | |
1da177e4 LT |
86 | |
87 | If you are unsure about this, say N here. | |
88 | ||
0458d5b4 AS |
89 | config USB_PERSIST |
90 | bool "USB device persistence during system suspend (DANGEROUS)" | |
91 | depends on USB && PM && EXPERIMENTAL | |
92 | default n | |
93 | help | |
b41a60ec AS |
94 | |
95 | If you say Y here and enable the "power/persist" attribute | |
96 | for a USB device, the device's data structures will remain | |
0458d5b4 | 97 | persistent across system suspend, even if the USB bus loses |
b41a60ec AS |
98 | power. (This includes hibernation, also known as swsusp or |
99 | suspend-to-disk.) The devices will reappear as if by magic | |
100 | when the system wakes up, with no need to unmount USB | |
101 | filesystems, rmmod host-controller drivers, or do anything | |
102 | else. | |
0458d5b4 AS |
103 | |
104 | WARNING: This option can be dangerous! | |
105 | ||
106 | If a USB device is replaced by another of the same type while | |
107 | the system is asleep, there's a good chance the kernel won't | |
108 | detect the change. Likewise if the media in a USB storage | |
109 | device is replaced. When this happens it's almost certain to | |
110 | cause data corruption and maybe even crash your system. | |
111 | ||
112 | If you are unsure, say N here. | |
113 | ||
1da177e4 LT |
114 | config USB_OTG |
115 | bool | |
116 | depends on USB && EXPERIMENTAL | |
117 | select USB_SUSPEND | |
118 | default n | |
119 | ||
120 | ||
121 | config USB_OTG_WHITELIST | |
122 | bool "Rely on OTG Targeted Peripherals List" | |
123 | depends on USB_OTG | |
124 | default y | |
125 | help | |
126 | If you say Y here, the "otg_whitelist.h" file will be used as a | |
127 | product whitelist, so USB peripherals not listed there will be | |
128 | rejected during enumeration. This behavior is required by the | |
129 | USB OTG specification for all devices not on your product's | |
130 | "Targeted Peripherals List". | |
131 | ||
132 | Otherwise, peripherals not listed there will only generate a | |
133 | warning and enumeration will continue. That's more like what | |
134 | normal Linux-USB hosts do (other than the warning), and is | |
135 | convenient for many stages of product development. | |
136 | ||
89ccbdc9 DB |
137 | config USB_OTG_BLACKLIST_HUB |
138 | bool "Disable external hubs" | |
139 | depends on USB_OTG | |
140 | help | |
141 | If you say Y here, then Linux will refuse to enumerate | |
142 | external hubs. OTG hosts are allowed to reduce hardware | |
143 | and software costs by not supporting external hubs. | |
1da177e4 | 144 |