I am using the SABRE Board for Smart Devices evaluation kit, which is based on the i.MX 6 processor. I have attached a micro USB to standard USB converter cable and a 4 port USB hub to the USB OTG connector of the card. When I just connect the mouse, it works. When I just connect the keyboard, that works, too. But when I connect both of them, neither the mouse nor the keyboard works.
There is nothing special about the mouse or the keyboard, both are generic devices (no fancy multimedia stuff on the keyboard and a standard wheel mouse). What could be the problem? The combined current draw of the keyboard/mouse might be exceeding the USB OTG port capacity, but I find this very unlikely. I know many people that connect more than two devices (keyboard, mouse, card reader) to smart phones like the Galaxy S4 and it works fine.
Currently, I have Android r13.4 running on this card and I am planning to switch over to Linux soon. Could this be related to Android?