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 12comment "Miscellaneous USB options" 13 depends on USB 14 15config 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 34 Most users want to say Y here. 35 36config USB_BANDWIDTH 37 bool "Enforce USB bandwidth allocation (EXPERIMENTAL)" 38 depends on USB && EXPERIMENTAL 39 help 40 If you say Y here, the USB subsystem enforces USB bandwidth 41 allocation and will prevent some device opens from succeeding 42 if they would cause USB bandwidth usage to go above 90% of 43 the bus bandwidth. 44 45 If you say N here, these conditions will cause warning messages 46 about USB bandwidth usage to be logged and some devices or 47 drivers may not work correctly. 48 49config USB_DYNAMIC_MINORS 50 bool "Dynamic USB minor allocation (EXPERIMENTAL)" 51 depends on USB && EXPERIMENTAL 52 help 53 If you say Y here, the USB subsystem will use dynamic minor 54 allocation for any device that uses the USB major number. 55 This means that you can have more than 16 of a single type 56 of device (like USB printers). 57 58 If you are unsure about this, say N here. 59 60config USB_SUSPEND 61 bool "USB selective suspend/resume and wakeup (EXPERIMENTAL)" 62 depends on USB && PM && EXPERIMENTAL 63 help 64 If you say Y here, you can use driver calls or the sysfs 65 "power/state" file to suspend or resume individual USB 66 peripherals. 67 68 Also, USB "remote wakeup" signaling is supported, whereby some 69 USB devices (like keyboards and network adapters) can wake up 70 their parent hub. That wakeup cascades up the USB tree, and 71 could wake the system from states like suspend-to-RAM. 72 73 If you are unsure about this, say N here. 74 75config USB_MULTITHREAD_PROBE 76 bool "USB Multi-threaded probe (EXPERIMENTAL)" 77 depends on USB && EXPERIMENTAL 78 default n 79 help 80 Say Y here if you want the USB core to spawn a new thread for 81 every USB device that is probed. This can cause a small speedup 82 in boot times on systems with a lot of different USB devices. 83 84 This option should be safe to enable, but if any odd probing 85 problems are found, please disable it, or dynamically turn it 86 off in the /sys/module/usbcore/parameters/multithread_probe 87 file 88 89 When in doubt, say N. 90 91config USB_OTG 92 bool 93 depends on USB && EXPERIMENTAL 94 select USB_SUSPEND 95 default n 96 97 98config USB_OTG_WHITELIST 99 bool "Rely on OTG Targeted Peripherals List" 100 depends on USB_OTG 101 default y 102 help 103 If you say Y here, the "otg_whitelist.h" file will be used as a 104 product whitelist, so USB peripherals not listed there will be 105 rejected during enumeration. This behavior is required by the 106 USB OTG specification for all devices not on your product's 107 "Targeted Peripherals List". 108 109 Otherwise, peripherals not listed there will only generate a 110 warning and enumeration will continue. That's more like what 111 normal Linux-USB hosts do (other than the warning), and is 112 convenient for many stages of product development. 113 114config USB_OTG_BLACKLIST_HUB 115 bool "Disable external hubs" 116 depends on USB_OTG 117 help 118 If you say Y here, then Linux will refuse to enumerate 119 external hubs. OTG hosts are allowed to reduce hardware 120 and software costs by not supporting external hubs. 121 122