TI中文支持网AM3352和4G模块通过USB接口连接，硬件设计时只连接USB的DP和DM管脚，4G模块直接有电源供电，芯片其他USB管脚全部悬空，请问这样有问题吗？
启动log如下
root@am335x:~# dmesg | grep "usb"[ 0.407190] usbcore: registered new interface driver usbfs[ 0.407285] usbcore: registered new interface driver hub[ 0.407639] usbcore: registered new device driver usb[ 1.547882] usbcore: registered new interface driver cdc_ether[ 1.553910] usbcore: registered new interface driver cdc_eem[ 1.559734] usbcore: registered new interface driver cdc_ncm[ 1.565534] usbcore: registered new interface driver huawei_cdc_ncm[ 1.571974] usbcore: registered new interface driver cdc_mbim[ 1.591129] usbcore: registered new interface driver cdc_acm[ 1.605010] usbcore: registered new interface driver cdc_wdm[ 1.610779] usbcore: registered new interface driver usb-storage[ 1.617025] usbcore: registered new interface driver usbserial[ 1.622971] usbcore: registered new interface driver usbserial_generic[ 1.629585] usbserial: USB Serial support registered for generic[ 1.635707] usbcore: registered new interface driver usb_debug[ 1.641615] usbserial: USB Serial support registered for debug[ 1.647550] usbcore: registered new interface driver io_edgeport[ 1.653658] usbserial: USB Serial support registered for Edgeport 2 port adap
ter[ 1.661135] usbserial: USB Serial support registered for Edgeport 4 port adap
ter[ 1.668645] usbserial: USB Serial support registered for Edgeport 8 port adap
ter[ 1.676147] usbserial: USB Serial support registered for EPiC device[ 1.682603] usbcore: registered new interface driver io_ti[ 1.688165] usbserial: USB Serial support registered for Edgeport TI 1 port a
dapter[ 1.695931] usbserial: USB Serial support registered for Edgeport TI 2 port a
dapter[ 1.703706] usbcore: registered new interface driver option[ 1.709362] usbserial: USB Serial support registered for GSM modem (1-port)[ 1.716431] usbcore: registered new interface driver qcaux[ 1.722016] usbserial: USB Serial support registered for qcaux[ 1.727928] usbcore: registered new interface driver qcserial[ 1.733777] usbserial: USB Serial support registered for Qualcomm USB modem[ 1.740819] usbcore: registered new interface driver safe_serial[ 1.746927] usbserial: USB Serial support registered for safe_serial[ 1.753387] usbcore: registered new interface driver usb_serial_simple[ 1.759993] usbserial: USB Serial support registered for zio[ 1.765751] usbserial: USB Serial support registered for funsoft[ 1.771859] usbserial: USB Serial support registered for flashloader[ 1.778299] usbserial: USB Serial support registered for vivopay[ 1.784408] usbserial: USB Serial support registered for moto_modem[ 1.790753] usbserial: USB Serial support registered for hp4x[ 1.796600] usbserial: USB Serial support registered for suunto[ 1.802622] usbserial: USB Serial support registered for siemens_mpi[ 1.809059] usbcore: registered new interface driver ti_usb_3410_5052[ 1.815607] usbserial: USB Serial support registered for TI USB 3410 1 port a
dapter[ 1.823374] usbserial: USB Serial support registered for TI USB 5052 2 port a
dapter[ 1.831154] usbcore: registered new interface driver cdc_xr_usb_serial[ 1.837736] xr_usb_serial_common: Exar USB UART (serial port) driver[ 1.846222] 47401300.usb-phy supply vcc not found, using dummy regulator[ 1.984264] musb-hdrc musb-hdrc.0.auto: Failed to request rx1.[ 1.990241] musb-hdrc musb-hdrc.0.auto: musb_init_controller failed with stat
us -517[ 1.998174] platform musb-hdrc.0.auto: Driver musb-hdrc requests probe deferr
al[ 2.006424] 47401b00.usb-phy supply vcc not found, using dummy regulator[ 2.104414] musb-hdrc musb-hdrc.1.auto: Failed to request rx1.[ 2.110370] musb-hdrc musb-hdrc.1.auto: musb_init_controller failed with stat
us -517[ 2.118305] platform musb-hdrc.1.auto: Driver musb-hdrc requests probe deferr
al[ 2.202751] usbcore: registered new interface driver usbhid[ 2.208360] usbhid: USB HID core driver[ 2.384880] musb-hdrc: ConfigData=0xde (UTMI-8, dyn FIFOs, bulk combine, bulk
split, HB-ISO Rx, HB-ISO Tx, SoftConn)[ 2.384902] musb-hdrc: MHDRC RTL version 2.0[ 2.384913] musb-hdrc: setup fifo_mode 4[ 2.384933] musb-hdrc: 28/31 max ep, 16384/16384 memory[ 2.385095] musb-hdrc musb-hdrc.0.auto: MUSB HDRC host driver[ 2.391341] musb-hdrc musb-hdrc.0.auto: new USB bus registered, assigned busnumber 1[ 2.399682] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002[ 2.406592] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=
1[ 2.413932] usb usb1: Product: MUSB HDRC host driver[ 2.418924] usb usb1: Manufacturer: Linux 3.14.46 musb-hcd[ 2.424467] usb usb1: SerialNumber: musb-hdrc.0.auto[ 2.485895] musb-hdrc: ConfigData=0xde (UTMI-8, dyn FIFOs, bulk combine, bulk
split, HB-ISO Rx, HB-ISO Tx, SoftConn)[ 2.485917] musb-hdrc: MHDRC RTL version 2.0[ 2.485929] musb-hdrc: setup fifo_mode 4[ 2.485947] musb-hdrc: 28/31 max ep, 16384/16384 memory[ 2.486102] musb-hdrc musb-hdrc.1.auto: MUSB HDRC host driver[ 2.492467] musb-hdrc musb-hdrc.1.auto: new USB bus registered, assigned busnumber 2[ 2.500640] usb usb2: New USB device found, idVendor=1d6b, idProduct=0002[ 2.507522] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=
1[ 2.514806] usb usb2: Product: MUSB HDRC host driver[ 2.519797] usb usb2: Manufacturer: Linux 3.14.46 musb-hcd[ 2.525329] usb usb2: SerialNumber: musb-hdrc.1.auto[ 2.591091] musb-hdrc musb-hdrc.0.auto: VBUS_ERROR in a_wait_vrise (81, <Sess
End), retry #1, port1 00000104[ 2.701305] musb-hdrc musb-hdrc.1.auto: VBUS_ERROR in a_wait_vrise (81, <Sess
End), retry #1, port1 00000104[ 2.743606] musb-hdrc musb-hdrc.0.auto: VBUS_ERROR in a_wait_vrise (81, <Sess
End), retry #2, port1 00000104[ 2.844656] musb-hdrc musb-hdrc.1.auto: VBUS_ERROR in a_wait_vrise (81, <Sess
End), retry #2, port1 00000104[ 2.896054] musb-hdrc musb-hdrc.0.auto: VBUS_ERROR in a_wait_vrise (81, <Sess
End), retry #3, port1 00000104[ 2.997102] musb-hdrc musb-hdrc.1.auto: VBUS_ERROR in a_wait_vrise (81, <Sess
End), retry #3, port1 00000104[ 3.048458] musb-hdrc musb-hdrc.0.auto: VBUS_ERROR in a_wait_vrise (80, <Sess
End), retry #3, port1 0008010c[ 3.149512] musb-hdrc musb-hdrc.1.auto: VBUS_ERROR in a_wait_vrise (80, <Sess
End), retry #3, port1 0008010c
Yaoming Qin：
usb 接鼠标，U盘可以正常工作吗？
usb部分的电路设计有截图吗？
ghostpipi：
回复 Yaoming Qin:
使用的是mini-pcie插座，没法试验鼠标和U盘
原来图见附件
Yaoming Qin：
回复 ghostpipi:
看了您的原理图，建议您参考ti的evm板进行usb部分设计，vbus和drv vbus都没有接，软件不支持，所以会报出上面的错误
leo chen：
回复 Yaoming Qin:
不接电源这种错误怎么也发生了
ghostpipi：
回复 Yaoming Qin:
Yaoming Qin
看了您的原理图，建议您参考ti的evm板进行usb部分设计，vbus和drv vbus都没有接，软件不支持，所以会报出上面的错误
在目前这种连接方法，能通过软件规避么？
ghostpipi：
回复 leo chen:
leo chen
不接电源这种错误怎么也发生了
问一下，如果AM只做host，VBUS也需要连接是吗？
Yaoming Qin：
回复 ghostpipi:
您用的是哪个版本的sdk？ AM335x测的vbus可以改为拉高到5v吗？
ghostpipi：
回复 Yaoming Qin:
Yaoming Qin
您用的是哪个版本的sdk？ AM335x测的vbus可以改为拉高到5v吗？
ti-processor-sdk-linux-am335x-evm-01.00.00.00-Linux-x86-Install.bin
今天问问硬件的同事看可以改不？如果可以的话，可以用软件规避是吗？
Yaoming Qin：
回复 ghostpipi:
软件方面，请您参考 linux-3.14.26-g2489c02/Documentation/devicetree/bindings/usb/am33xx-usb.txt ， 对linux-3.14.26-g2489c02/arch/arm/boot/dts/am33xx.dtsi 中的dr_mode 进行修改。
ghostpipi：
回复 Yaoming Qin:
现在把vbus拉倒5V了，dr_mode改成host了，但是也没识别，但是输出
[ 6.852136] musb-hdrc musb-hdrc.0.auto: otg: usb_otg_kick_fsm: invalid host/gadget device
