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Date:      Tue, 10 Mar 1998 07:43:19 +0100 (MET)
From:      Luigi Rizzo <luigi@labinfo.iet.unipi.it>
To:        garycorc@idt.net (Gary T. Corcoran)
Cc:        adhir@worldbank.org, multimedia@FreeBSD.ORG
Subject:   Re: sound in -current
Message-ID:  <199803100643.HAA08610@labinfo.iet.unipi.it>
In-Reply-To: <3504E04D.DCAF67ED@idt.net> from "Gary T. Corcoran" at Mar 10, 98 01:39:54 am

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> I never had time to write up a proper report on this, but when I was trying
> to get sound going on my notebook PC, I found that when (at first) I had
> the two DMA channels reversed in my config file (since I didn't know which
> was which in Luigi's driver) my machine locked solid when I tried to play
> a sound file.  Reversing the DMA's fixed the problem.  Did something change

what do you mean by "DMA chan reversed", and, especially, what hardware
caused the problem ?

> about a possible conig error, but not a lockup.  Could you perhaps detect
> this situation, Luigi?   When I get some more time I'll write up some

i'll do my best...

the thing is, two buffers are allocated in the driver, and the 8237 is
started on both channels. "Reversing" the channels as you claim should
have the effect that write dma request go to a 8237 channel
programmed for reads, so the request is not honored (probably) by the
8237. Then what could happen is that the soundcard is continuously
issuing request causing some kind of freeze on the ISA bus ?

detecting the problem is very card specific though...

	cheers
	luigi
-----------------------------+--------------------------------------
Luigi Rizzo                  |  Dip. di Ingegneria dell'Informazione
email: luigi@iet.unipi.it    |  Universita' di Pisa
tel: +39-50-568533           |  via Diotisalvi 2, 56126 PISA (Italy)
fax: +39-50-568522           |  http://www.iet.unipi.it/~luigi/
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