connect the device to ubuntu, use command $sudo lsusb will display like:
mean: Spreadtrum device idVendor 1782 idProduct 5d24
1, touch the file:
~/.android/adb_usb.ini
add 0x1782 to adb_usb.ini --- this num is your device‘s idVender
====no this file will occur:
adb devices display none
2, touch /etc/udev/rules.d/88-android.rules
add below to this file: the num 1782 is your device‘s idVender
SUBSYSTEM=="usb", ATTRS{idVendor}=="1782", MODE="0666"
after this exec command: sudo service udev restart
==no this file will occur:
adb devices display like below
Then exec:
adb kill-server
adb start-server
now your adb setup is ok;
$adb shell
----------mian_G