Oh ! I just realized my mistake. Actually it is not the kernel that is faulty but my configuration (since I migrated from debian wheezy to jessie). I had connection/disconnection issues because of conflicts between gammu and ModemManager. It is also ModemManager which took the control of my phone and switched to 3G network. Now that I disabled NetworkManager for my phone, I don't have such issues any more with kernel 3.16 or 4.0 (backlight still extincts, but that's by design for my phone) Sorry for that. Kind regards Fab -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in