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

[Pharaoh .]

okay, I am on ARM..so better I do not use preallocation scheme with
CONTINUOUS flag in case I want to mmap my dma buffer. In fact, I tried
mmaping it, but it didn't work as expected.

On 7/12/07, Takashi Iwai <tiwai at suse.de> wrote:
> 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
>