Hello everybody
I am trying to implement an android dock on linux, and there is some cases where alsa seems to not properly recognise the Android phone as a USB sound device...
First a little bit of context
since Android 4.1 it is possible to put an android phone (connected to a PC via USB) in "dock mode" Basically you send a couple of special USB packet to the phone and the phone will disconnect from the USB bus then reconnect as a USB sound device. You can then use any tool to handle it as an audio source and redirct the sound to your speaker.
For those intereset the details can be found at
http://source.android.com/tech/accessories/aoap/aoa2.html
This works really well, no problem with that...
However Android also has something called "accessory mode" which is used to create custom apps that communicate in "raw" mode with the host
my problems arrive when both the dock mode and the accessory mode are enabled. in that case Alsa will not recognise the usb sound device exposed by android. It will create an entry for it in /proc/asound but there are no mixer or input stream
I attach the output of lsusb -v in both cases and a small C program that I use to put the phone in the proper modes
(there is a small section of code to (un)comment to en/disable accessory mode, it uses libusb for usb access and should be trivial to compile with it)
At this point I am not sure how to proceed, is this a real bug or something not implemented ? what extra info do I need to provide ? any help would be welcome
Regards
Jérémy Rosen
fight key loggers : write some perl using vim