我用我手上的Linux image(20140117版本)测试了一下,开机后是有/dev/bus/usb目录的,而且里面也有对应USB Host Controller以及连接在其之上的DM9621网卡网卡的信息
[root@FriendlyARM /]# ls -lR /dev/bus/usb
/dev/bus/usb:
drwxr-xr-x 2 root root 0 Jan 1 2013 1
drwxr-xr-x 2 root root 0 Jan 1 2013 2
/dev/bus/usb/1:
crw-r--r-- 1 root root 189, 0 Jan 1 2013 1
crw-r--r-- 1 root root 189, 1 Jan 1 2013 2
crw-r--r-- 1 root root 189, 2 Jan 1 2013 3
crw-r--r-- 1 root root 189, 3 Jan 1 2013 4
/dev/bus/usb/2:
crw-r--r-- 1 root root 189, 128 Jan 1 2013 1
[root@FriendlyARM /]#
[root@FriendlyARM /]#
[root@FriendlyARM /]# lsusb
Bus 2 Device 1: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 1 Device 1: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 1 Device 2: ID 0424:2640 Standard Microsystems Corp.
Bus 1 Device 4: ID 0a46:9621 Davicom Semiconductor, Inc.
Bus 1 Device 3: ID 0424:4040 Standard Microsystems Corp.