lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[PATCH] USB: real nodes instead of usbfs

Browse Source 
This patch introduces a /sys/class/usb_device/ class
where every connected usb-device will show up:

  tree /sys/class/usb_device/
  /sys/class/usb_device/
  |-- usb1.1
  |   |-- dev
  |   `-- device -> ../../../devices/pci0000:00/0000:00:1d.0/usb1
  |-- usb2.1
  |   |-- dev
  |   `-- device -> ../../../devices/pci0000:00/0000:00:1d.1/usb2
  ...

The presence of the "dev" file lets udev create real device nodes.
  kay@pim:~/src/linux-2.6> tree /dev/bus/usb/
  /dev/bus/usb/
  |-- 1
  |   `-- 1
  |-- 2
  |   `-- 1
  ...

udev rule:
  SUBSYSTEM="usb_device", PROGRAM="/sbin/usb_device %k", NAME="%c"
  (echo $1 | /bin/sed 's/usb\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/')

This makes libusb pick up the real nodes instead of the mounted usbfs:
  export USB_DEVFS_PATH=/dev/bus/usb

Background:
  All this makes it possible to manage usb devices with udev instead of
  the devfs solution. We are currently working on a pam_console/resmgr
  replacement driven by udev and a pam-helper. It applies ACL's to device
  nodes, which is required for modern desktop functionalty like
  "Fast User Switching" or multiple local login support.

New patch with its own major. I've succesfully disabled usbfs and use real
nodes only on my box. With: "export USB_DEVFS_PATH=/dev/bus/usb" libusb picks
up the udev managed nodes instead of reading usbfs files.

This makes udev to provide symlinks for libusb to pick up:
  SUBSYSTEM="usb_device", PROGRAM="/sbin/usbdevice %k", SYMLINK="%c"

/sbin/usbdevice:
  #!/bin/sh
  echo $1 | /bin/sed 's/usbdev\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/'

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Kay Sievers
2005-07-31 01:05:53 +02:00
committed by Greg Kroah-Hartman
parent 22af8878d2
commit fbf82fd2e1
7 changed files with 114 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/usb.h
View File

@ -5,6 +5,7 @@
#include <linux/usb_ch9.h>
#define USB_MAJOR 180
#define USB_DEVICE_MAJOR 189
#ifdef __KERNEL__
@ -349,6 +350,7 @@ struct usb_device {
char *manufacturer;
char *serial; /* static strings from the device */
struct list_head filelist;
struct class_device *class_dev;
struct dentry *usbfs_dentry; /* usbfs dentry entry for the device */
/*