Subject: Re: [PATCH] Sam440ep support

From: Benjamin Herrenschmidt <[email-masked]>
Date: Tue, 06 May 2008 09:44:18 +1000

On Mon, 2008-05-05 at 21:50 +0200, Gerhard Pircher wrote:
> This is a (bad) hack that I also use on the AmigaOne to get the ALSA
> sound
> drivers working with DMA, because ALSA doesn't work with
> dma-noncoherent.c.
> The problem is the "nopage" mechanism, which fails with non coherent
> DMA
> allocations due to their own virtual address space (correct me, if I'm
> wrong).
> 
> See this thread for more info:
> http://readlist.com/lists/vger.kernel.org/linux-kernel/45/226541.html
> 
> This is a general problem that affects all powerpc boards that use
> dma-noncoherent.c with ALSA PCI drivers.

The link above doesn't provide any useful information on the problem and
it contains itself a non working link...

Can somebody explains exactly what's going on ? That shouldn't be hard
to fix. I can't believe the problem has been around for 2 years and
nobody actually bothered fixing it properly.

Send me a sound card that needs that hack and I can take care of it
myself.

Ben.