I use a Lenovo P1 mobile. I was able to connect the mobile to the PC through the USB charging cable which came with the box. As soon as I connect the USB to the PC, a notification would show in my mobile "USB Setting(not exactly sure)". I used to click on the notification and I was able to change the setting from "Charge only" to "MTP (Media Transfer". Thus, I was able to add my file to the Mobiles(songs, lectures etc).
Recently, after updating my Phone to Android 6.0.1; I am unable to do so. I have tried searching for the USB settings manually, but to no avail.
I would appreciate if you would help me.