# # USB Core configuration # config USB_DEBUG bool "USB verbose debug messages" depends on USB help Say Y here if you want the USB core & hub drivers to produce a bunch of debug messages to the system log. Select this if you are having a problem with USB support and want to see more of what is going on. comment "Miscellaneous USB options" depends on USB config USB_DEVICEFS bool "USB device filesystem" depends on USB ---help--- If you say Y here (and to "/proc file system support" in the "File systems" section, above), you will get a file /proc/bus/usb/devices which lists the devices currently connected to your USB bus or busses, and for every connected device a file named "/proc/bus/usb/xxx/yyy", where xxx is the bus number and yyy the device number; the latter files can be used by user space programs to talk directly to the device. These files are "virtual", meaning they are generated on the fly and not stored on the hard drive. You may need to mount the usbfs file system to see the files, use mount -t usbfs none /proc/bus/usb For the format of the various /proc/bus/usb/ files, please read . Most users want to say Y here. config USB_BANDWIDTH bool "Enforce USB bandwidth allocation (EXPERIMENTAL)" depends on USB && EXPERIMENTAL help If you say Y here, the USB subsystem enforces USB bandwidth allocation and will prevent some device opens from succeeding if they would cause USB bandwidth usage to go above 90% of the bus bandwidth. If you say N here, these conditions will cause warning messages about USB bandwidth usage to be logged and some devices or drivers may not work correctly. config USB_DYNAMIC_MINORS bool "Dynamic USB minor allocation (EXPERIMENTAL)" depends on USB && EXPERIMENTAL help If you say Y here, the USB subsystem will use dynamic minor allocation for any device that uses the USB major number. This means that you can have more than 16 of a single type of device (like USB printers). If you are unsure about this, say N here. config USB_SUSPEND bool "USB selective suspend/resume and wakeup (EXPERIMENTAL)" depends on USB && PM && EXPERIMENTAL help If you say Y here, you can use driver calls or the sysfs "power/state" file to suspend or resume individual USB peripherals. Also, USB "remote wakeup" signaling is supported, whereby some USB devices (like keyboards and network adapters) can wake up their parent hub. That wakeup cascades up the USB tree, and could wake the system from states like suspend-to-RAM. If you are unsure about this, say N here. config USB_MULTITHREAD_PROBE bool "USB Multi-threaded probe (EXPERIMENTAL)" depends on USB && EXPERIMENTAL default n help Say Y here if you want the USB core to spawn a new thread for every USB device that is probed. This can cause a small speedup in boot times on systems with a lot of different USB devices. This option should be safe to enable, but if any odd probing problems are found, please disable it, or dynamically turn it off in the /sys/module/usbcore/parameters/multithread_probe file When in doubt, say N. config USB_OTG bool depends on USB && EXPERIMENTAL select USB_SUSPEND default n config USB_OTG_WHITELIST bool "Rely on OTG Targeted Peripherals List" depends on USB_OTG default y help If you say Y here, the "otg_whitelist.h" file will be used as a product whitelist, so USB peripherals not listed there will be rejected during enumeration. This behavior is required by the USB OTG specification for all devices not on your product's "Targeted Peripherals List". Otherwise, peripherals not listed there will only generate a warning and enumeration will continue. That's more like what normal Linux-USB hosts do (other than the warning), and is convenient for many stages of product development. config USB_OTG_BLACKLIST_HUB bool "Disable external hubs" depends on USB_OTG help If you say Y here, then Linux will refuse to enumerate external hubs. OTG hosts are allowed to reduce hardware and software costs by not supporting external hubs.