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

Takashi Iwai tiwai at suse.de
Thu Jan 14 08:54:08 CET 2010


At Thu, 14 Jan 2010 08:46:38 +0100,
Andreas Mohr wrote:
> 
> On Wed, Jan 13, 2010 at 10:07:32AM +0100, Takashi Iwai wrote:
> > > 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.
> > 
> > A quick patch below (totally untested!) might do that.
> > It's passing the device struct blindly, so not sure whether this would
> > actually work for all dma_alloc_coherent().
> 
> Thanks a lot, tested, but AFAICS there isn't much of a change unfortunately
> (log below).

Of course, not for the crash.  The patch was for improving the sound
quality (if any).


Takashi


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