USB: set default y for CONFIG_USB_DEVICE_CLASS

[linux-2.6-omap-h63xx.git] / drivers / usb / core / Kconfig

diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
index 2fc0f88a3d860818947002ed91d8213a51d22f8f..346fc030c929ae172b6658df8f1a2b54113e1ac3 100644 (file)
--- a/drivers/usb/core/Kconfig
+++ b/drivers/usb/core/Kconfig
@@ -31,7 +31,34 @@ config USB_DEVICEFS
          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.
+         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)"