Opening this new thread is a call to all ubuntu users her: maybe you can help out. I cannot connect to my mi2s using adb. When I unplug the mi2s and connect my old HTC Desire S (with miuiandroid latest build), "adb devices" shows me my device. That's why I guess that adb itself is not the problem. There is another thread where someone posted a solution for ubuntu. This solution doesn't work for me (and someone else commenting). So I would be glad if you could post here how you got your device seen by the adb. I would love to install wiui ROM or custom recovery, but I would prefer having some sort of access to the system. Just to complete it: I neither have access to my mi2s in fastboot: "no permissions". (htc shows up as it should, and YES, on both phones "developer options -> usb debugging" is turned on.) I am pretty sure I had to modify udev-rules in order to see my old phone.