uaudio patch for accepts only fixed sampling rate

[takawata at jp.freebsd.org]

In message <20040531172057.GD92188 at cnd.mcgill.ca>, Mathew Kanner wrote:
>On May 30, takawata at jp.freebsd.org wrote:
>> Hi, I bought a USB speaker that accepts 
>> 48khz audio bitrate only. And current uaudio code 
>> try to set if device cannot accept bitrate change request.
>> 
>> So I wrote a patch
>> 
>> http://www.init-main.com/uaudio.diff
>> 
>> This code is partly copy-n-paste from NetBSD specific
>> part now. With this code, upper layer can see it is 
>> not acceptable and invoke format converter.
>
>	Hey,
>	I'm also working on USB audio.  It just doesn't work for me
>and I'm getting a ton locking issues.  At the moment, I've merged most
>of the netbsd uaudio stuff.  My question to you is, does uaudio work
>in fbsd 5+ for you?

Yes, it works for me. 
And I found a bug that will break unit management for pcm layer.
It is already committed.