From alsa-user-owner@alsa.jcu.cz  Wed Oct  7 08:37:59 1998
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	Wed, 7 Oct 1998 08:33:21 +0200
Date: Wed, 7 Oct 1998 08:33:11 +0200 (CEST)
From: Jaroslav Kysela <perex@jcu.cz>
To: Forrest Cahoon <forrest@pconline.com>
cc: alsa-user@jcu.cz
Subject: Re: snd-gusclassic.o: init_module: Device or resource busy
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On Tue, 6 Oct 1998, Forrest Cahoon wrote:

> On Tue, Oct 06, 1998 at 10:58:25AM +0200, Jaroslav Kysela wrote:
> > On Tue, 6 Oct 1998, Forrest Cahoon wrote:
> > 
> > > I've got a GUS Classic in my Zeos Pentium 90, and I can't seem to get
> > > the ALSA drivers to work.  I've got OSS/Lite to work, both compiled
> > > into the kernel (2.0.35) and as a module, so I know the settings are
> > > right: IRQ 11, io address 0x220, both DMA's set to 1.  [ ... ]
> 
> > > options snd-gusclassic snd_port=0x220 snd_irq=11 snd_dma1=1 snd_dma2=1
> > 
> > If you want disable second DMA channel use:
> > 
> > options snd-gusclassic snd_port=0x220 snd_irq=11 snd_dma1=1 snd_dma2=-1
> > 
> > 							Jaroslav
> 
> I did this, and I've got my card to work!  At least playback, that is.
> 
> I'd like to get recording working, too, but I am confused about what
> dma1 and dma2 actually are now, and I want to understand clearly.
> 
> I've been looking thru the manuals I got with this card, and this is
> what it looks like: dma1 is for playback and dma2 is for record.
> Having them *both* set to 1 is the factory default, and it would work
> that way under DOS/Windows, with the following caveat:
> 
> _Gravis Ultrasound User's Guide_, p. 10:
> 
> "If you wish to record and play simultaneously, be sure to set
> different DMA channels for Playback and Recording.  (The frequency
> must be the same for both.)"
> 
> I'm not sure what "frequency" is being referred to in that passage.
> 
> 
> I also noticed this advice on p. 5 of the _User's Guide_, in a section
> called "For Best Digital Recording - Read This":
> 
> "Try a 16-bit DMA channel.  Because some motherboards do not have
> working 16-bit DMA channels, UltraSound's default DMA is an 8-bit
> channel.  (The 8-bit channels are 0-3; the 16-bit channels are 4-7.)
> If the 16-bit DMA channels work on your computer, use one --
> performance, especially stereo recording, will be better.  If strange
> things happen with the 16-bit channel, switch back to a free 8-bit
> channel."
> 
> 
> >From these passages I guess I should set dma1 and dma2 to seperate
> channels in the 4-7 range.  I'm not running Windows anywhere so I
> can't run the config software that came with the card -- is there any
> way for me to change them in Linux?

Simply set snd_dma1 & snd_dma2 to different values except DMA 0 and DMA 4.
ALSA driver does all necessary setup for GF1 chip.

> I'm also worried about conflicts.  I found /proc/dma and it looks like
> this:
> 
>  1: GF1 record
>  4: cascade
> 
> I thought dma1 was playback!  I did successfully play an audio file;
> did it maybe not use DMA?  And what is cascade?  Is that also

If you use shared DMA mode (if you disable second DMA, ALSA driver enable
this shared mode), both directions (playback and record) are routed over
one DMA channel. This mean - if you use playback, playback is using
snd_dma1 and if you use record - it is using snd_dma1, too. Due to this
reason, you cannot use playback and record at same time (duplex).

cascade - it's limitation by PC architecture. DMA 4 is blocked with first
8-bit DMA controller and cannot be used.

> soundcard related, or something completely different?  I also have a
> 3c509 network card which is not currently installed, but which I will
> want to re-install.  Will it want a DMA channel, and if so, how do I
> avoid a conflict?

3c509 doesn't use any DMA channel.

						Jaroslav

-----
Jaroslav Kysela <perex@jcu.cz>
Academic Computer Centre, University of South Bohemia
Branisovska 31, C. Budejovice, CZ-370 05 Czech Republic


