Subject: Re: [PATCH] Sam440ep support

From: "Gerhard Pircher" <[email-masked]>
Date: Tue, 06 May 2008 11:16:22 +0200

-------- Original-Nachricht --------
> Datum: Tue, 06 May 2008 18:48:39 +1000
> Von: Benjamin Herrenschmidt <[email-masked]>
> An: Gerhard Pircher <[email-masked]>
> CC: [email-masked], Takashi Iwai <[email-masked]>, [email-masked], [email-masked]
> Betreff: Re: [PATCH] Sam440ep support

> 
> On Tue, 2008-05-06 at 09:51 +0200, Gerhard Pircher wrote:
> > Takashi Iwai posted a preliminary patch a long time ago. I tested it
> > on my machine and it failed with non coherent scatter-gather DMA
> > allocations (I guess almost all ALSA PCI drivers use SG DMA?).
> 
> How does Alsa allocate such SG ?
I can't answer this question. *ducked* :-) Takashi?

FYI: I posted the results of the test with Takashi's dma_mmap_coherent
patch here:
http://ozlabs.org/pipermail/linuxppc-dev/2006-June/024078.html

On the other side it looks like this problem does not only affect ALSA.
As far as I can tell also some V4L(2) drivers have a problem with mmaping
non coherent DMA allocations, but I'm not sure (it's a long time since I
did some tests with video cards on my AmigaOne).

Naturally I can do some tests, if you or Takashi come up with a new
patch.

Thanks!

Gerhard

-- 
GMX startet ShortView.de. Hier findest Du Leute mit Deinen Interessen!
Jetzt dabei sein: http://www.shortview.de/?mc=sv_ext_mf@gmx