For the format of the various /proc/bus/usb/ files, please read
<file:Documentation/usb/proc_usb_info.txt>.
- 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.
+ Usbfs files 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. The usbfs functionality is replaced by real
+ device-nodes managed by udev. These nodes live in /dev/bus/usb and
+ are used by libusb.
+
+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)"