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Date: Thu, 14 Apr 2005 13:11:02 -0400
From: Mathew Kanner <mat@cnd.mcgill.ca>
To: Alexander Leidinger <Alexander@Leidinger.net>
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cc: freebsd-multimedia@freebsd.org
cc: Mathew Kanner <mat@cnd.mcgill.ca>
cc: julian@elischer.org
Subject: Re: de-dma uaudio
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On Apr 14, Alexander Leidinger wrote:
> Mathew Kanner <mat@cnd.mcgill.ca> wrote:
> 
> >>Do I understand this patch right: it changes from DMA access to non-DMA
> >>access?
> >>
> >>If yes: can someone please explain me why this is a good thing?
> >
> >	Upper layer does not use DMA.  It just isn't use so why
> >allocate special memeory for it.
> 
> And our USB stack ([eou]hci) can't ever grow the feature of doing DMA?

	That's a lower layer.  I'm removing the DMA mem allocation in
the PCM layer.  The uaudio driver does it's own buffer allocation
(though I don't think it's dma capable at that layer, but when it
is...)  It's bad that we have to do so many copies but we can't just
easily rewrite the uaudio driver.
	--Mat
--