From alsa-devel-owner@alsa.jcu.cz  Fri Mar 12 16:08:15 1999
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Date: Fri, 12 Mar 1999 16:07:51 +0100
From: Thomas Sailer <sailer@ife.ee.ethz.ch>
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To: alsa-devel@alsa.jcu.cz
Subject: Re: Enlarging the dma buffer for audiopci
References: <48A7CB4095A7D11187EF00609748374C02F161AF@w1sxms01.mobilkom.at>
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T.Mertes@mobilkom.at wrote:

> I know that there are other ways to solve the problem.
> (sound demon/playing program which use threads and
> big buffers.) But I want first to investigate possibilitys to

No, the right solution is to mark the sound producing
app as RT, because sound is inherently RT.

>   - Is it possible to enlarge the buffer of the audiopci driver
>     to even several megabytes (configurabel like it is now).

That would be a serious waste of memory

>   - Is there a built in ALSA or PCI-DMA limit which
>     prohibits it? Can we lift this limit?

The buffer must be physically contiguous. It is already
difficult under the normal circumstances to allocate
128k phys. contiguous, and impossible with the current
kernel facilities to allocate more physically contiguous.

Tom

