ADB is not detecting the device I am running an Ubuntu 14 host machine on my PC and recently I got an Eragon 820 Development kit which is running on Android Marshmallow, everything was working fine until I click the factory reset option in the Android settings.

After that the adb / fastboot neither working and In the Dmesg am getting like this 

[  308.326141] usb 2-1.3: new high-speed USB device number 18 using ehci-pci
[  308.420065] usb 2-1.3: New USB device found, idVendor=18d1, idProduct=d001
[  308.420072] usb 2-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  308.420076] usb 2-1.3: Product: MSM8996 for arm64
[  308.420079] usb 2-1.3: Manufacturer: unknown
[  308.420083] usb 2-1.3: SerialNumber: 77a941ec
[  310.055562] usb 2-1.3: usbfs: USBDEVFS_CONTROL failed cmd adb rqt 128 rq 6 len 256 ret -110
[  311.971228] usb 2-1.3: USB disconnect, device number 18


these same 8 lines keep on repeating (i.e. the device connects, is recognized, some adb rqt… fails, device is disconnected again).

Anyone know how to fix this issue?
Did you enable the developer options again after doing a factory reset?If not follow the below steps to enable it.

Go to Settings, About phone and tap on build number 7 times to unlock/enable Developer options again (factory reset would've put it back to the default of locked/disabled).

Enable USB debugging from the developer options after the above step for adb/fastboot to work.