5.4-PRERELEASE usb audio problem

Doug White dwhite at gumbysoft.com
Fri Apr 8 22:48:35 PDT 2005

On Sat, 2 Apr 2005, Christian Laursen wrote:

> When I plug in my Logitech USB headset I get the following:
> uaudio0: Logitech Logitech USB Headset, rev 1.10/1.13, addr 2
> uaudio_add_selector: NOT IMPLEMENTED
> uaudio0: audio rev 1.00
> pcm1: <USB Audio> on uaudio0
> pcm1: chn_init(pcm1:play:0) failed: err = 19
> pcm1: pcm_chn_create(ua_chan, 1, 0xc1974780) failed
> uhid0: Logitech Logitech USB Headset, rev 1.10/1.13, addr 2, iclass 1/1
> With 5.3 and earlier it used to at least work for playback but now
> it seems to be completely broken.
> I saw a lot of commits to uaudio, including recording support. Does
> something need to be merged from -CURRENT for it to work properly?

My analysis of the -CURRENT code indicates that there is missing
functionality to implement this USB audio device.  It requires
synchronization to be run over a separate endpoint and the code to do that
does not exist.

The checks protected by #ifndef UAUDIO_MULTIPLE_ENDPOINTS is where you
need to implement the functionality.  The USB specs are completely open,
but I don't know if sufficient support functions exist yet for performing
the scheduling necessary to manage these types of endpoints.

It may have worked before since input AudioStreaming interfaces were
simply ignored, but now there is code to deal with input from stand-alone
synchronous pipes and it rejects other configs due to the unimplemented

Doug White                    |  FreeBSD: The Power to Serve
dwhite at gumbysoft.com          |  www.FreeBSD.org

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