usb 拔出插入android log：
Line 568: 06-16 01:09:42.075 3270 3463 D UsbHostManager: Removed device at /dev/bus/usb/001/003: TransMemory Line 1699: 06-16 01:09:43.099 3270 3463 D UsbHostManager: USB device attached: vidpid 0930:6544 mfg/product/ver/serial TOSHIBA /TransMemory /1.00/C412F52D6C79C1C06002BDF2 hasAudio/HID/Storage: false/false/true Line 1707: 06-16 01:09:43.104 3270 3463 D UsbHostManager: Added device UsbDevice[mName=/dev/bus/usb/001/004,mVendorId=2352,mProductId=25924,mClass=0,mSubclass=0,mProtocol=0,mManufacturerName=TOSHIBA ,mProductName=TransMemory ,mVersion=1.00,mSerialNumberReader=com.android.server.usb.UsbSerialReader@f1e5805,mConfigurations=[ Line 1708: 06-16 01:09:43.104 3270 3463 D UsbHostManager: UsbConfiguration[mId=1,mName=null,mAttributes=128,mMaxPower=100,mInterfaces=[ Line 1709: 06-16 01:09:43.104 3270 3463 D UsbHostManager: UsbInterface[mId=0,mAlternateSetting=0,mName=null,mClass=8,mSubclass=6,mProtocol=80,mEndpoints=[ Line 1710: 06-16 01:09:43.104 3270 3463 D UsbHostManager: UsbEndpoint[mAddress=129,mAttributes=2,mMaxPacketSize=512,mInterval=255] Line 1711: 06-16 01:09:43.104 3270 3463 D UsbHostManager: UsbEndpoint[mAddress=2,mAttributes=2,mMaxPacketSize=512,mInterval=255]]]]