2 # USB Core configuration
5 bool "USB verbose debug messages"
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.
12 config USB_ANNOUNCE_NEW_DEVICES
13 bool "USB announce new devices"
17 Say Y here if you want the USB core to always announce the
18 idVendor, idProduct, Manufacturer, Product, and SerialNumber
19 strings for every new USB device to the syslog. This option is
20 usually used by distro vendors to help with debugging and to
21 let users know what specific device was added to the machine
24 If you do not want this kind of information sent to the system
25 log, or have any doubts about this, say N here.
27 comment "Miscellaneous USB options"
31 bool "USB device filesystem"
34 If you say Y here (and to "/proc file system support" in the "File
35 systems" section, above), you will get a file /proc/bus/usb/devices
36 which lists the devices currently connected to your USB bus or
37 busses, and for every connected device a file named
38 "/proc/bus/usb/xxx/yyy", where xxx is the bus number and yyy the
39 device number; the latter files can be used by user space programs
40 to talk directly to the device. These files are "virtual", meaning
41 they are generated on the fly and not stored on the hard drive.
43 You may need to mount the usbfs file system to see the files, use
44 mount -t usbfs none /proc/bus/usb
46 For the format of the various /proc/bus/usb/ files, please read
47 <file:Documentation/usb/proc_usb_info.txt>.
49 Usbfs files can't handle Access Control Lists (ACL), which are the
50 default way to grant access to USB devices for untrusted users of a
51 desktop system. The usbfs functionality is replaced by real
52 device-nodes managed by udev. These nodes live in /dev/bus/usb and
55 config USB_DEVICE_CLASS
56 bool "USB device class-devices (DEPRECATED)"
60 Userspace access to USB devices is granted by device-nodes exported
61 directly from the usbdev in sysfs. Old versions of the driver
62 core and udev needed additional class devices to export device nodes.
64 These additional devices are difficult to handle in userspace, if
65 information about USB interfaces must be available. One device
66 contains the device node, the other device contains the interface
67 data. Both devices are at the same level in sysfs (siblings) and one
68 can't access the other. The device node created directly by the
69 usb device is the parent device of the interface and therefore
70 easily accessible from the interface event.
72 This option provides backward compatibility for libusb device
73 nodes (lsusb) when usbfs is not used, and the following udev rule
75 SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \
76 NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644"
78 config USB_DYNAMIC_MINORS
79 bool "Dynamic USB minor allocation (EXPERIMENTAL)"
80 depends on USB && EXPERIMENTAL
82 If you say Y here, the USB subsystem will use dynamic minor
83 allocation for any device that uses the USB major number.
84 This means that you can have more than 16 of a single type
85 of device (like USB printers).
87 If you are unsure about this, say N here.
90 bool "USB selective suspend/resume and wakeup"
93 If you say Y here, you can use driver calls or the sysfs
94 "power/level" file to suspend or resume individual USB
95 peripherals and to enable or disable autosuspend (see
96 Documentation/usb/power-management.txt for more details).
98 Also, USB "remote wakeup" signaling is supported, whereby some
99 USB devices (like keyboards and network adapters) can wake up
100 their parent hub. That wakeup cascades up the USB tree, and
101 could wake the system from states like suspend-to-RAM.
103 If you are unsure about this, say N here.
106 bool "USB device persistence during system suspend (DANGEROUS)"
107 depends on USB && PM && EXPERIMENTAL
111 If you say Y here and enable the "power/persist" attribute
112 for a USB device, the device's data structures will remain
113 persistent across system suspend, even if the USB bus loses
114 power. (This includes hibernation, also known as swsusp or
115 suspend-to-disk.) The devices will reappear as if by magic
116 when the system wakes up, with no need to unmount USB
117 filesystems, rmmod host-controller drivers, or do anything
120 WARNING: This option can be dangerous!
122 If a USB device is replaced by another of the same type while
123 the system is asleep, there's a good chance the kernel won't
124 detect the change. Likewise if the media in a USB storage
125 device is replaced. When this happens it's almost certain to
126 cause data corruption and maybe even crash your system.
128 If you are unsure, say N here.
132 depends on USB && EXPERIMENTAL
137 config USB_OTG_WHITELIST
138 bool "Rely on OTG Targeted Peripherals List"
142 If you say Y here, the "otg_whitelist.h" file will be used as a
143 product whitelist, so USB peripherals not listed there will be
144 rejected during enumeration. This behavior is required by the
145 USB OTG specification for all devices not on your product's
146 "Targeted Peripherals List".
148 Otherwise, peripherals not listed there will only generate a
149 warning and enumeration will continue. That's more like what
150 normal Linux-USB hosts do (other than the warning), and is
151 convenient for many stages of product development.
153 config USB_OTG_BLACKLIST_HUB
154 bool "Disable external hubs"
157 If you say Y here, then Linux will refuse to enumerate
158 external hubs. OTG hosts are allowed to reduce hardware
159 and software costs by not supporting external hubs.