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To: "David E. Cross" <dec@phoenix.its.rpi.edu>
cc: Luigi Rizzo <luigi@labinfo.iet.unipi.it>, hackers@FreeBSD.ORG,
        multimedia@FreeBSD.ORG
Subject: Re: IRQ problem (was Re: IRQ timing) 
In-reply-to: Your message of "Sat, 30 Aug 1997 20:57:04 EDT."
             <Pine.BSF.3.96.970830203904.15813B-100000@phoenix.its.rpi.edu> 
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Date: Sat, 30 Aug 1997 19:58:40 -0700
From: Amancio Hasty <hasty@rah.star-gate.com>
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We need a little bit more of information:
o OS version
o is the card using auto dma?
o dma channels being used for the sound card
o name of the app
o buffer size used in in the application
o complete dmesg output  -- i want to know cpu model, etc..
o sound card brand/model

	Tnks,
	Amancio

>From The Desk Of "David E. Cross" :
> On Sat, 30 Aug 1997, Luigi Rizzo wrote:
> 
> > > I just sent a message to the OSS people, and they mentioned that some of
> > > the problem I am experiencing is a result of some tight IRQ timing that
> > > the FreeBSD kernel has (ie, it takes too long to transfer the data).  I
> > 
> > 
> > would you care to mention what problem are you experiencing ?
> > 
> > Curiously I have a related question, so hope people would excluse the
> > crosspost..
> > 
> 
> The exact problem is that at the highest sampling rate
> (44.1KHz/16Bit/Stereo) I get skips in the music, even in an unloaded
> system.  I emailed 4front-tech about this and said that it was a known
> problem due to FreeBSD's tightness in the IRQ code.  I was hoping that
> this was something that could be fairly easily changed (ie. a #define
> somewhere).  (They did mention that they had spoken to some of the kernel
> team about this).
> 
> Are there any beta patches, or pointers where to start digging.  I have
> already started poking arround in /usr/src/sys/i386/isa.
> 
> --
> David Cross
> ACS Consultant
>