[alsa-devel] Can I mmap buffer allocated using SNDRV_DMA_TYPE_CONTINUOUS?

[Takashi Iwai]

At Wed, 11 Jul 2007 18:17:49 +0530,
Pharaoh . wrote:
> 
> On 7/11/07, Pharaoh . <pharaoh137 at gmail.com> wrote:
> >
> > Hi,
> > I have allocated the DMA buffer using snd_pcm_lib_malloc_pages() and
> > it was preallocated as:
> >
> > snd_pcm_lib_preallocate_pages_for_all(pcm,
> >                                              SNDRV_DMA_TYPE_CONTINUOUS,
> >                                              snd_dma_continuous_data
> >                                              (GFP_KERNEL),
> >                                              128 * 1024, 128 * 1024);
> >
> > Can I mmap such a dma buffer? I think yes...
> >
> > -pharaoh.
> >
> 
> 
> I dont think it can be mmapped.

It can be basically, but not on all architectures.
For example, ARM has a problem with coherency.


Takashi