de-dma uaudio
Mathew Kanner
mat at cnd.mcgill.ca
Thu Apr 14 10:11:51 PDT 2005
On Apr 14, Alexander Leidinger wrote:
> Mathew Kanner <mat at 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
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