1# 2# USB Core configuration 3# 4config 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 12config USB_ANNOUNCE_NEW_DEVICES 13 bool "USB announce new devices" 14 depends on USB 15 default N 16 help 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 22 in what location. 23 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. 26 27comment "Miscellaneous USB options" 28 depends on USB 29 30config USB_DEVICEFS 31 bool "USB device filesystem" 32 depends on USB 33 ---help--- 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. 42 43 You may need to mount the usbfs file system to see the files, use 44 mount -t usbfs none /proc/bus/usb 45 46 For the format of the various /proc/bus/usb/ files, please read 47 <file:Documentation/usb/proc_usb_info.txt>. 48 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 53 are used by libusb. 54 55config USB_DEVICE_CLASS 56 bool "USB device class-devices (DEPRECATED)" 57 depends on USB 58 default y 59 ---help--- 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. 63 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. 71 72 This option provides backward compatibility for libusb device 73 nodes (lsusb) when usbfs is not used, and the following udev rule 74 doesn't exist: 75 SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \ 76 NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644" 77 78config USB_DYNAMIC_MINORS 79 bool "Dynamic USB minor allocation (EXPERIMENTAL)" 80 depends on USB && EXPERIMENTAL 81 help 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). 86 87 If you are unsure about this, say N here. 88 89config USB_SUSPEND 90 bool "USB selective suspend/resume and wakeup" 91 depends on USB && PM 92 help 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). 97 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. 102 103 If you are unsure about this, say N here. 104 105config USB_PERSIST 106 bool "USB device persistence during system suspend (DANGEROUS)" 107 depends on USB && PM && EXPERIMENTAL 108 default n 109 help 110 111 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 118 else. 119 120 WARNING: This option can be dangerous! 121 122 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. 127 128 If you are unsure, say N here. 129 130config USB_OTG 131 bool 132 depends on USB && EXPERIMENTAL 133 select USB_SUSPEND 134 default n 135 136 137config USB_OTG_WHITELIST 138 bool "Rely on OTG Targeted Peripherals List" 139 depends on USB_OTG 140 default y 141 help 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". 147 148 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. 152 153config USB_OTG_BLACKLIST_HUB 154 bool "Disable external hubs" 155 depends on USB_OTG 156 help 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. 160 161