When running lsusb (not as root) with an OTG adapter plugged in without anything plugged into it I get :
u0_a83@flounder:/ $ lsusb
Bus 001 Device 001: ID 1d6b:0002
Bus 002 Device 001: ID 1d6b:0002
Bus 003 Device 001: ID 1d6b:0002
Is this normal with USB OTG adapters.
Also a USB hub is recognized as another device in lsusb when plugged using OTG
Yes, that is absolutely normal. The host controller can detect the presence of the cable since pins 4 & 5 are bridged.
On my device I ran lsusb with a USB key connected via OTG, then with only the OTG cable connected, then with nothing:
$ lsusb
Bus 001 Device 002: ID 1221:3234
Bus 001 Device 001: ID 1d6b:0002
Bus 002 Device 001: ID 1d6b:0003
$ lsusb
Bus 001 Device 001: ID 1d6b:0002
Bus 002 Device 001: ID 1d6b:0003
$ lsusb
Exactly as expected. Your device appears to have one more bus compared to mine.
Q & A