[alsa-devel] [RFC PATCH 0/2] Add support for audio cards with multiple endpoints on the one interface

Eduard Gilmutdinov edgilmutdinov at gmail.com
Tue May 13 06:08:49 CEST 2014

Devices of company Focusrite (Novation) contain multiple endpoints on a single interface. In particular (1235:0010) "Novation Saffire 6 USB" on one interface have endpoints for playback and capture. Functions "set_format" and "pcm_close" are generated when new stream is creating and when it is closing respectively. They contain a function call "usb_set_interface" which resets interface and endpoints on it. Thus it is imposible to capture and playback a sound at the same time. To avoid this, suggest to monitor the status of the interface and endpoint on it. Status of endpoints can be monitored by the field "enabled" of the structure "usb_host_endpoint". This approach should not affect for the audio cards with one endpoint on the interface.

Please correct me if I'm wrong.

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