USB I/O from libusb/NDK longer working in Anrdroid N?

[Rocky Zhang]

Hello,

I just upgraded my Nexus 5X to Android N and found couple of Applications based on libusb cannot work.

These applications are all using libusb native shared object to interact with USB devices that is connected to the Android phone. 

Seems the USB transaction cannot be established successfully, program even having problem polling the device descriptors.  

I understand ADK seems to be the android standard interacting with USB peripherals, but ADK hasn't been updated since 2012 and still doesn't support isochronous transfer. While libusb can fill this gap and supporting a lot of USB devices. For instance, CameraFI App is built on top of libuvc, which relies on libusb, and can provide access to USB Video Camera devices on Android phone. I also tried to lookup Android N changes on USB, and seems the latest API document didn't mentioned this either.

So, my questions is, has USB access been disabled in the Android framework layer?  And is there any new suggested way of working with USB peripherals? 

Thanks,

Rocky

[Glenn Kasten]

This is likely issue https://code.google.com/p/android/issues/detail?id=205565

If there is a specific feature you need added to the supported SDK API,

please file an issue for that feature request.   For example this is a feature request for isochronous:

https://code.google.com/p/android/issues/detail?id=219327

[Rocky Zhang]

Hi Glenn,

Thanks for the links. Looks like it is a Selinux issue. Hmm, I wonder is this a bug or it is kind of enhanced security feature of N? 

Thanks,

Rocky

[Glenn Kasten]

Sorry, I don't have anything more at this time beyond my previous reply above.