DM8168不支持usb hub设备，是硬件限制还是软件的呢？

我手头有一个kinect摄像头，插入DM8168的usb口后，串口得到输出：

usb 1-1: new high speed USB device using musb-hdrc and address 2

usb 1-1: New USB device found, idVendor=0409, idProduct=005a

usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0

hub 1-1:1.0: USB hub found

hub 1-1:1.0: 3 ports detected

usb 1-1.2: new full speed USB device using musb-hdrc and address 3

usb 1-1.2: device descriptor read/64, error -71

usb 1-1.2: device descriptor read/64, error -71

usb 1-1.2: new full speed USB device using musb-hdrc and address 4

usb 1-1.2: device descriptor read/64, error -71

usb 1-1.2: device descriptor read/64, error -71

usb 1-1.2: new full speed USB device using musb-hdrc and address 5

usb 1-1.2: device not accepting address 5, error -71

usb 1-1.2: new full speed USB device using musb-hdrc and address 6

usb 1-1.2: device not accepting address 6, error -71

hub 1-1:1.0: unable to enumerate USB device on port 2

usb 1-1: reset high speed USB device using musb-hdrc and address 2

usb 1-1.2: new full speed USB device using musb-hdrc and address 7

usb 1-1.2: device descriptor read/64, error -71

usb 1-1.2: device descriptor read/64, error -71

usb 1-1.2: new full speed USB device using musb-hdrc and address 8

usb 1-1.2: device descriptor read/64, error -71

usb 1-1.2: device descriptor read/64, error -71

usb 1-1.2: new full speed USB device using musb-hdrc and address 9

usb 1-1.2: device not accepting address 9, error -71

usb 1-1.2: new full speed USB device using musb-hdrc and address 10

我想确认下，这是什么原因引起的呢？

急，请知道原因的回复一下呢，非常感谢！

Feng Dong：

-71是protocol error,应该和驱动相关,你用的是什么驱动

Eric Mao：

回复 Feng Dong:

恩，-71是protocol error, 产生的原因应该是发送给hub的请求，都会被忽略。在TI的文档上有这么一句话

multipoint/hub support (applicable for PG1.X) : The multipoint support in musb controller IP is disabled. Due

to this limitation only one usb device can be connected to one usb port and HUB cannot be supported.

Feng Dong：

回复 Eric Mao:

具体见errata,其中有详细描述

xing lixing：

回复 Eric Mao:

不错