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.
+config USB_ANNOUNCE_NEW_DEVICES
+ bool "USB announce new devices"
+ depends on USB
+ default N
+ help
+ Say Y here if you want the USB core to always announce the
+ idVendor, idProduct, Manufacturer, Product, and SerialNumber
+ strings for every new USB device to the syslog. This option is
+ usually used by distro vendors to help with debugging and to
+ let users know what specific device was added to the machine
+ in what location.
+
+ If you do not want this kind of information sent to the system
+ log, or have any doubts about this, say N here.
+
comment "Miscellaneous USB options"
depends on USB
config USB_DEVICEFS
- bool "USB device filesystem"
+ bool "USB device filesystem (DEPRECATED)"
depends on USB
---help---
If you say Y here (and to "/proc file system support" in the "File
For the format of the various /proc/bus/usb/ files, please read
<file:Documentation/usb/proc_usb_info.txt>.
- Please note that this code is completely unrelated to devfs, the
- "/dev file system support".
+ Modern Linux systems do not use this.
- Most users want to say Y here.
+ Usbfs entries are files and not character devices; usbfs can't
+ handle Access Control Lists (ACL) which are the default way to
+ grant access to USB devices for untrusted users of a desktop
+ system.
-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.
+ The usbfs functionality is replaced by real device-nodes managed by
+ udev. These nodes lived in /dev/bus/usb and are used by libusb.
- 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_DEVICE_CLASS
+ bool "USB device class-devices (DEPRECATED)"
+ depends on USB
+ default y
+ ---help---
+ Userspace access to USB devices is granted by device-nodes exported
+ directly from the usbdev in sysfs. Old versions of the driver
+ core and udev needed additional class devices to export device nodes.
+
+ These additional devices are difficult to handle in userspace, if
+ information about USB interfaces must be available. One device
+ contains the device node, the other device contains the interface
+ data. Both devices are at the same level in sysfs (siblings) and one
+ can't access the other. The device node created directly by the
+ usb device is the parent device of the interface and therefore
+ easily accessible from the interface event.
+
+ This option provides backward compatibility for libusb device
+ nodes (lsusb) when usbfs is not used, and the following udev rule
+ doesn't exist:
+ SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \
+ NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644"
config USB_DYNAMIC_MINORS
- bool "Dynamic USB minor allocation (EXPERIMENTAL)"
- depends on USB && EXPERIMENTAL
+ bool "Dynamic USB minor allocation"
+ depends on USB
help
If you say Y here, the USB subsystem will use dynamic minor
allocation for any device that uses the USB major number.
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
+ bool "USB runtime power management (suspend/resume and wakeup)"
+ depends on USB && PM_RUNTIME
help
If you say Y here, you can use driver calls or the sysfs
- "power/state" file to suspend or resume individual USB
- peripherals.
+ "power/level" file to suspend or resume individual USB
+ peripherals and to enable or disable autosuspend (see
+ Documentation/usb/power-management.txt for more details).
Also, USB "remote wakeup" signaling is supported, whereby some
USB devices (like keyboards and network adapters) can wake up
If you are unsure about this, say N here.
-
config USB_OTG
bool
depends on USB && EXPERIMENTAL
- select USB_SUSPEND
+ depends on USB_SUSPEND
default n
config USB_OTG_WHITELIST
bool "Rely on OTG Targeted Peripherals List"
- depends on USB_OTG
- default y
+ depends on USB_OTG || EMBEDDED
+ default y if USB_OTG
+ default n if EMBEDDED
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".
+ "Targeted Peripherals List". "Embedded Hosts" are likewise
+ allowed to support only a limited number of peripherals.
Otherwise, peripherals not listed there will only generate a
warning and enumeration will continue. That's more like what
config USB_OTG_BLACKLIST_HUB
bool "Disable external hubs"
- depends on USB_OTG
+ depends on USB_OTG || EMBEDDED
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.
+ and software costs by not supporting external hubs. So
+ are "Embedded Hosts" that don't offer OTG support.