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From: Luigi Rizzo <luigi@labinfo.iet.unipi.it>
Message-Id: <199708310424.GAA03702@labinfo.iet.unipi.it>
Subject: Re: IRQ problem (was Re: IRQ timing)
To: hasty@rah.star-gate.com (Amancio Hasty)
Date: Sun, 31 Aug 1997 06:24:16 +0200 (MET DST)
Cc: dec@phoenix.its.rpi.edu, hackers@FreeBSD.ORG, multimedia@FreeBSD.ORG
In-Reply-To: <199708310523.WAA00779@rah.star-gate.com> from "Amancio Hasty" at Aug 30, 97 10:22:44 pm
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> > > o buffer size used in in the application
> > 
> > i guess you also need the blocksize -- the size of each DMA transfers
> > -- and not only the total amount of buffers.
> 
> True but bear in mind that the system has plenty of memory:
...
> I would hope that the OSS driver has the heuristics to allocate 
> sufficient memory for the buffers.

I think the default is 64K (seen in some include file). What I am not
sure about is if the blocksize for DMA transfer is determined
adaptively if the user does not call some SETFRAGMENT or SUBDIVIDE
ioctl. In my code I wrote some code to use 0.25s of audio for each DMA
transfer unless the user specifies elsewhere (using the above calls or
the new one that I introduced, AIOSSIZE).

What about guspnpXX ?

	Luigi