Device disconnection occurred when like the below exception happened in an Android device. It was a temporary disconnection, probably, so the device got back to normal immediately. But that was not “USB disconnected” situation…
E UsbDeviceManager: Could not read kernel function list
E UsbDeviceManager: java.io.FileNotFoundException: /sys/class/android_usb/android0/functions: open failed: ENOENT (No such file or directory)
E UsbDeviceManager: at libcore.io.IoBridge.open(IoBridge.java:496)
E UsbDeviceManager: at java.io.FileInputStream.<init>(FileInputStream.java:159)
E UsbDeviceManager: at android.os.FileUtils.readTextFile(FileUtils.java:614)
E UsbDeviceManager: at com.android.server.usb.UsbDeviceManager$UsbHandler.dump(UsbDeviceManager.java:1312)
E UsbDeviceManager: at com.android.server.usb.UsbDeviceManager.dump(UsbDeviceManager.java:2065)
E UsbDeviceManager: at com.android.server.usb.UsbService.dump(UsbService.java:612)
E UsbDeviceManager: at android.os.Binder.doDump(Binder.java:818)
E UsbDeviceManager: at android.os.Binder.dump(Binder.java:808)
E UsbDeviceManager: at android.os.Binder.onTransact(Binder.java:744)
E UsbDeviceManager: at android.hardware.usb.IUsbManager$Stub.onTransact(IUsbManager.java:682)
E UsbDeviceManager: at android.os.Binder.execTransactInternal(Binder.java:1021)
E UsbDeviceManager: at android.os.Binder.execTransact(Binder.java:994)
E UsbDeviceManager: Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory)
E UsbDeviceManager: at libcore.io.Linux.open(Native Method)
E UsbDeviceManager: at libcore.io.ForwardingOs.open(ForwardingOs.java:167)
E UsbDeviceManager: at libcore.io.BlockGuardOs.open(BlockGuardOs.java:252)
E UsbDeviceManager: at libcore.io.IoBridge.open(IoBridge.java:482)
E UsbDeviceManager: ... 11 more
W BatteryExternalStatsWorker: modem info is invalid: ModemActivityInfo{ mTimestamp=0 mSleepTimeMs=0 mIdleTimeMs=0 mTxTimeMs[]=[0, 0, 0, 0, 0] mRxTimeMs=0 mEnergyUsed=0}
~ my tech diary ~ 