Re: Using preallocate pci, isa or nothing?

[Takashi Iwai <tiwai@suse.de>]

At Wed, 11 Feb 2004 14:39:47 -0600,
Mathieu Rondonneau wrote:
> 
> 
> 
> > At Sun, 8 Feb 2004 18:29:10 -0600,
> > Mathieu Rondonneau wrote:
> > >
> > > Hi,
> > > I'm sorry for the html format, these are some questions according to my
> > > problems.
> > >
> > > I'm writing an ALSA driver for a CSB337 board (AT91RM9200). There is no
> PCI
> > > or ISA on this board. Should I preallocate memory with:
> > > snd_pcm_lib_preallocate_pages_for_all,
> > > snd_pcm_lib_preallocate_isa_pages_for_all() or
> > > snd_pcm_lib_preallocate_pci_pages_for_all()?
> > >
> > > There is a specific DMA (PDC) on the AT91RM9200, so i'm trying to use
> > > snd_pcm_lib_preallocate_pages_for_all() but seems complicated to
> understand
> > > what is needed by the ALSA pcm and what i have to write.
> > > What does the function snd_..._pointer() mean? should i need it if i
> don't
> > > use ISA or PCI mecanism?
> > > What does the function snd_pcm_period_elapsed() mean? Should i need it
> if i
> > > don't use ISA or PCI mecanism?
> >
> > did you take a look at my document?
> >
> > http://www.alsa-project.org/~iwai/writing-an-alsa-driver/
> >
> >
> > Takashi
> >
> 
> Yes I did, and i thank you for your work, your document is very helpfull.
> But, i'm not familiar with ALSA driver development.
> Could I use PCI or ISA mecanism (memory allocation and dma) even if there
> are no PCI or ISA bus in my board?

then, no.

but note that the functions you asked above have basically nothing to
do with PCI or ISA.  the whole preallocation meachanism is provided
for the abstraction regardless of BUS type.
also, pcm and control callbacks are also irrelevant to BUS type.


Takashi


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