[alsa-devel] [PATCH 2/3] ASoC: Blackfin: add multi-channel supporting in Blackfin ASoC driver and AD1980 codec driver
tiwai at suse.de
Tue Oct 21 12:08:19 CEST 2008
At Tue, 21 Oct 2008 10:49:16 +0100,
Mark Brown wrote:
> On Tue, Oct 21, 2008 at 05:48:56PM +0800, Cai, Cliff wrote:
> > >From: Takashi Iwai [mailto:tiwai at suse.de]
> > >But, CONFIG_SND_MULTICHAN_SUPPORT would change any buffer
> > >allocation behavior? I don't find it...
> > It will change the ac97 frame size defined in bf5xx-ac97.h,the frame
> > size the basic unit of the DMA buffer
> So this is purely a restriction in the driver, rather than a property of
> the hardware - is there any reason why you can't change the size of
> buffer that you allocate at runtime?
It'd be possible, as far as I understand. It's rather a design
bf5xx driver preallocates the max size buffer. Otherwise you may get
no large buffer at later fragmentation. And that size is different
between with and without multi-channel support.
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