[alsa-devel] [PATCH 0/5] PCM mmap (temporary) fixes for non-coherent architectures

Andreas Mohr andi at lisas.de
Wed Jan 13 10:28:25 CET 2010


On Tue, Jan 12, 2010 at 08:02:36AM +0100, Takashi Iwai wrote:
> At Fri, 1 Jan 2010 20:31:30 +0100,
> Andreas Mohr wrote:
> > 
> > Hi,
> > 
> > I've tried this patch set (with the typo-corrected part 4) on my ASUS
> > WL-500gP v2 MIPSEL via a backport to, but all I get is a
> > small blip of the sound I wanted to play, and then the system is fubar
> > (I believe just the same thing as what happened without having this patch
> > applied).

Crap, you already managed to beat me to my own reply! ;)
(I'll try your patch in the other mail _ASAP_)

> As I mentioned in the previous followup, if your device is a
> USB-audio, the patch doesn't help because it's for devices with
> buffers using dma_alloc_coherent().  For USB-audio, it uses vmalloc
> for an intermediate buffer.  Maybe this should be changed to dma_*()
> stuff for such architectures.

I've been searching the mailing list postings up and down,
but I couldn't deduce anything to that effect from that content
(but I'm mailing list-externally - maybe I just really didn't find the
correct posting or there was a threading split)

> Nevertheless, I don't know whether the crash is related with the
> audio part...

Yes, I wasn't fully pointing at the crash being caused by insufficient
patches in that area either...
(but I haven't fully investigated these OOPSes yet)

Thanks a lot for your new test patch,

Andreas Mohr

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