[alsa-devel] [Fwd: Filling "Struct snd_dma_buffer" manually]
ghjeold_i_mwee at cox.net
Thu Jul 24 18:45:51 CEST 2008
> I am stuck with a problem please help me.
> I have allocated a buffer in ram and i want that if i playback something
> from user end then alsa library exchanges data with this buffer using
> memory mapping but for this i have to fill a
> structure "snd_dma_buffer" in driver code but as i have told i dont
> want to use dma so i have to fill it manually with address of ram
> Please tell me if it is possible if yes then help me.
> Thanks in advance..
> Dinesh Dua
I don't know the part of alsa you are working with so I
can't answer your question. But I have some advice.
The list you are posting to is called alsa-devel. The
devel stands for development, but it really isn't meant
for development using alsa, but development of alsa.
If the developers choose to they might answer your
question. Or not. The other list for alsa is
alsa-user, and this is for users of the api as well as
end users of alsa. Again, you might have luck there
with your query, or not.
However, your question is very ill formed. To you your
problem is immediate and obvious, you understand the
context, you know all the details. No one on this list
does. You are more likely to get help if you explain
the context of your question at a higher level. What
are you trying to accomplish? How are you trying to
accomplish it? Also put in snippets of code
illustrating your approach where appropriate. This
gives the information someone needs to answer your
question. Someone might even be able to give you a
better way to accomplish what you want to do. But no
guarantees, this is a mailing list, no one is required
Your other alternative is to 'use the source'. All of
the source for alsa is available, so you can look at
that source to see if what you want to do is possible,
and how it would have to be done. You could probably
start with a grep of snd_dma_buffer in the library and
driver source trees. This will likely bring up many
hits, but you can then search for other context in
those hits to find the area of interest. Then read the
code to see how it works.
Slightly slower than getting a ready made answer, but
surer. The code doesn't lie.
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