11da177e4SLinus Torvalds# 21da177e4SLinus Torvalds# USB Core configuration 31da177e4SLinus Torvalds# 41da177e4SLinus Torvaldsconfig USB_DEBUG 51da177e4SLinus Torvalds bool "USB verbose debug messages" 61da177e4SLinus Torvalds depends on USB 71da177e4SLinus Torvalds help 81da177e4SLinus Torvalds Say Y here if you want the USB core & hub drivers to produce a bunch 91da177e4SLinus Torvalds of debug messages to the system log. Select this if you are having a 101da177e4SLinus Torvalds problem with USB support and want to see more of what is going on. 111da177e4SLinus Torvalds 121da177e4SLinus Torvaldscomment "Miscellaneous USB options" 131da177e4SLinus Torvalds depends on USB 141da177e4SLinus Torvalds 151da177e4SLinus Torvaldsconfig USB_DEVICEFS 161da177e4SLinus Torvalds bool "USB device filesystem" 171da177e4SLinus Torvalds depends on USB 181da177e4SLinus Torvalds ---help--- 191da177e4SLinus Torvalds If you say Y here (and to "/proc file system support" in the "File 201da177e4SLinus Torvalds systems" section, above), you will get a file /proc/bus/usb/devices 211da177e4SLinus Torvalds which lists the devices currently connected to your USB bus or 221da177e4SLinus Torvalds busses, and for every connected device a file named 231da177e4SLinus Torvalds "/proc/bus/usb/xxx/yyy", where xxx is the bus number and yyy the 241da177e4SLinus Torvalds device number; the latter files can be used by user space programs 251da177e4SLinus Torvalds to talk directly to the device. These files are "virtual", meaning 261da177e4SLinus Torvalds they are generated on the fly and not stored on the hard drive. 271da177e4SLinus Torvalds 281da177e4SLinus Torvalds You may need to mount the usbfs file system to see the files, use 291da177e4SLinus Torvalds mount -t usbfs none /proc/bus/usb 301da177e4SLinus Torvalds 311da177e4SLinus Torvalds For the format of the various /proc/bus/usb/ files, please read 321da177e4SLinus Torvalds <file:Documentation/usb/proc_usb_info.txt>. 331da177e4SLinus Torvalds 341da177e4SLinus Torvalds Please note that this code is completely unrelated to devfs, the 351da177e4SLinus Torvalds "/dev file system support". 361da177e4SLinus Torvalds 371da177e4SLinus Torvalds Most users want to say Y here. 381da177e4SLinus Torvalds 391da177e4SLinus Torvaldsconfig USB_BANDWIDTH 401da177e4SLinus Torvalds bool "Enforce USB bandwidth allocation (EXPERIMENTAL)" 411da177e4SLinus Torvalds depends on USB && EXPERIMENTAL 421da177e4SLinus Torvalds help 431da177e4SLinus Torvalds If you say Y here, the USB subsystem enforces USB bandwidth 441da177e4SLinus Torvalds allocation and will prevent some device opens from succeeding 451da177e4SLinus Torvalds if they would cause USB bandwidth usage to go above 90% of 461da177e4SLinus Torvalds the bus bandwidth. 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds If you say N here, these conditions will cause warning messages 491da177e4SLinus Torvalds about USB bandwidth usage to be logged and some devices or 501da177e4SLinus Torvalds drivers may not work correctly. 511da177e4SLinus Torvalds 521da177e4SLinus Torvaldsconfig USB_DYNAMIC_MINORS 531da177e4SLinus Torvalds bool "Dynamic USB minor allocation (EXPERIMENTAL)" 541da177e4SLinus Torvalds depends on USB && EXPERIMENTAL 551da177e4SLinus Torvalds help 561da177e4SLinus Torvalds If you say Y here, the USB subsystem will use dynamic minor 571da177e4SLinus Torvalds allocation for any device that uses the USB major number. 581da177e4SLinus Torvalds This means that you can have more than 16 of a single type 591da177e4SLinus Torvalds of device (like USB printers). 601da177e4SLinus Torvalds 611da177e4SLinus Torvalds If you are unsure about this, say N here. 621da177e4SLinus Torvalds 631da177e4SLinus Torvaldsconfig USB_SUSPEND 64f3f3253dSDavid Brownell bool "USB selective suspend/resume and wakeup (EXPERIMENTAL)" 651da177e4SLinus Torvalds depends on USB && PM && EXPERIMENTAL 661da177e4SLinus Torvalds help 671da177e4SLinus Torvalds If you say Y here, you can use driver calls or the sysfs 681da177e4SLinus Torvalds "power/state" file to suspend or resume individual USB 69f3f3253dSDavid Brownell peripherals. 70f3f3253dSDavid Brownell 71f3f3253dSDavid Brownell Also, USB "remote wakeup" signaling is supported, whereby some 72f3f3253dSDavid Brownell USB devices (like keyboards and network adapters) can wake up 73f3f3253dSDavid Brownell their parent hub. That wakeup cascades up the USB tree, and 74f3f3253dSDavid Brownell could wake the system from states like suspend-to-RAM. 751da177e4SLinus Torvalds 761da177e4SLinus Torvalds If you are unsure about this, say N here. 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds 791da177e4SLinus Torvaldsconfig USB_OTG 801da177e4SLinus Torvalds bool 811da177e4SLinus Torvalds depends on USB && EXPERIMENTAL 821da177e4SLinus Torvalds select USB_SUSPEND 831da177e4SLinus Torvalds default n 841da177e4SLinus Torvalds 851da177e4SLinus Torvalds 861da177e4SLinus Torvaldsconfig USB_OTG_WHITELIST 871da177e4SLinus Torvalds bool "Rely on OTG Targeted Peripherals List" 881da177e4SLinus Torvalds depends on USB_OTG 891da177e4SLinus Torvalds default y 901da177e4SLinus Torvalds help 911da177e4SLinus Torvalds If you say Y here, the "otg_whitelist.h" file will be used as a 921da177e4SLinus Torvalds product whitelist, so USB peripherals not listed there will be 931da177e4SLinus Torvalds rejected during enumeration. This behavior is required by the 941da177e4SLinus Torvalds USB OTG specification for all devices not on your product's 951da177e4SLinus Torvalds "Targeted Peripherals List". 961da177e4SLinus Torvalds 971da177e4SLinus Torvalds Otherwise, peripherals not listed there will only generate a 981da177e4SLinus Torvalds warning and enumeration will continue. That's more like what 991da177e4SLinus Torvalds normal Linux-USB hosts do (other than the warning), and is 1001da177e4SLinus Torvalds convenient for many stages of product development. 1011da177e4SLinus Torvalds 102*89ccbdc9SDavid Brownellconfig USB_OTG_BLACKLIST_HUB 103*89ccbdc9SDavid Brownell bool "Disable external hubs" 104*89ccbdc9SDavid Brownell depends on USB_OTG 105*89ccbdc9SDavid Brownell help 106*89ccbdc9SDavid Brownell If you say Y here, then Linux will refuse to enumerate 107*89ccbdc9SDavid Brownell external hubs. OTG hosts are allowed to reduce hardware 108*89ccbdc9SDavid Brownell and software costs by not supporting external hubs. 1091da177e4SLinus Torvalds 110