[alsa-devel] [PATCH 2/3] ASoC: Blackfin: add multi-channel supporting in Blackfin ASoC driver and AD1980 codec driver

[Mark Brown]

On Tue, Oct 21, 2008 at 05:55:23PM +0800, Bryan Wu wrote:

> But you know, it is very difficult for us to allocate big buffer in an
> NOMMU machine (such as Blackfin) on the fly, So we prefer to allocate
> them at the beginning. And in the embedded world, when the user want
> to use multi-channel function, they will enable this option. If they
> don't, they won't do that. It is very simple for both us and our
> users, although it is less elegant than Mark's idea.

So the issue is that you want to force a static allocation at startup
due to hardware limitations?  That makes a bit more sense.  I guess
that's OK but I'd suggest changing the code to also allow the user to
select four channels - not all multi-channel systems use six channels.
Another option would be to select it at driver startup time.

I'm still not sure that this is something that should be selected via
the kernel configuration rather than by the machine driver - I would
expect the use of six channels to be a property of the system rather
than of the particular kernel build.