[alsa-devel] [Q] playing / recording mono on a stereo-only hardware

Guennadi Liakhovetski g.liakhovetski at gmx.de
Thu Feb 4 21:24:18 CET 2010

On Thu, 4 Feb 2010, Raymond Yau wrote:

I would see your reply sooner, if you used reply-to-all.

> if LIBASOUND_DEBUG = 1 cannot tell you which parameter fail in hw_params() ,
> you will need to define RULES_DEBUG in alsa-kernel/core/pcm_native.c and
> compile driver with debug=verbose
> -#undef RULES_DEBUG
> +#define RULES DEBUG 1

That's already on too. Not sure what you mean by "compile driver with 
debug=verbose," supposedly, some kernel ALSA debug parameter. Since this 
is my driver, I can certainly add any debugging there, but it seems 
obvious to me, that the kernel is still getting a mono configuration, 
which shouldn't be the cae.

> you can find out how ALSA refine the hw parameters by examing the system log

If you mean "dmesg" output, then, as I said, there isn't much to look for 
there - the kernel is configured for mono...

Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer

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