TI中文支持网我们制作了一个新的电路板，使用了am5728芯片，使用tusb4041i来扩展usb2.0接口。
我没有对内核进行任何关于usb配置方面的修改。
下面是板子启动的打印信息：
[ 76.654585] usbcore: regstered new interface driver usbfs
[ 76.660739] usbcore: registered new interface driver hub
[ OK ] Reached target Sound Card.[ 76.660824] usbcore: registered new device driver usb
[ 76.685752] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller
[ 76.691820] xhci-hcd xhci-hcd.1.auto: new USB bus registered, assigned bus number 1
[ 76.700028] xhci-hcd xhci-hcd.1.auto: hcc params 0x0220f04c hci version 0x100 quirks 0x00210010
[ 76.708843] xhci-hcd xhci-hcd.1.auto: irq 438, io mem 0x48890000
[ 76.715539] hub 1-0:1.0: USB hub found
[ 76.719324] hub 1-0:1.0: 1 port detected
[ 76.724294] omap_hsmmc 480b4000.mmc: could not find pctldev for node /ocp/padconf@4844a000/mmc2_iodelay_ddr_3_3v_conf, deferring probe
[ 76.736927] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller
[ 76.743361] xhci-hcd xhci-hcd.1.auto: new USB bus registered, assigned bus number 2
Starting rc.pvr.service…[ 76.751285] usb usb2: We don't know the algorithms for LPM for this host, disabling LPM.
[ 76.752459] omap_hsmmc 480b4000.mmc: could not find pctldev for node /ocp/padconf@4844a000/mmc2_iodelay_ddr_3_3v_conf, deferring probe
[ 76.774478] hub 2-0:1.0: USB hub found
[ 76.778322] hub 2-0:1.0: 1 port detected
请问上面的信息是不是讲usb2.0和usb3.0总线都已经正常工作了？
root@am57xx-evm:~# lsusb -t
/: Bus 02.Port 1: Dev 1, class="root_hub", Driver=xhci-hcd/1p, 5000M
/: Bus 01.Port 1: Dev 1, class="root_hub", Driver=xhci-hcd/1p, 480M
但是这里还是没有检测到tusb4041i这个设备，请问这是由什么原因导致的呢？
求解答
Kailyn Chen：
这个问题可能只能帮分析下TUSB4041I部分。 软件部分我建议去SItara论坛，sitara做主控的话，那边应该会有关于USB的程序参考一下呢。
