Re: DOOM sound bug workaround

Steve VanDevender (stevev@efn.org)
Mon, 6 Jan 1997 23:20:47 -0800


Hannu Savolainen writes:
> On Fri, 3 Jan 1997, Steve VanDevender wrote:
>
> > For quite a while, I've had a problem with DOOM where the sound stops
> > and the sound driver to emit messages like this after some random amount
> > of play:
> >
> > linux: Sound: DMA (output) timed out - IRQ/DRQ config error?
> >
> > This has been happening at least since 1.2.13. Everyone's tried to
> > convince me it's some kind of hardware problem, but I know that DMA
> > works with my SCSI card completely reliably.
> DMA by a SCSI card is a completely different thing than DMA with a
> soundcard. A soundcard requires every byte right in time or otherwise an
> underrun occurs. DMA with a SCSI card doesn't have this kind of requirements.
>
> It's very possible that some SCSI activity during sound playback causes your
> problem. This is the case at least if you use a PAS16 soundcard together
> with an AHA1542 SCSI controller.

My soundcard is a GUS classic (<Gravis UltraSound 3.7 (1024k)> at 0x220
irq 12 dma 6,7) and my SCSI card is a Buslogic 545C. I also had this
problem before I had a SCSI card and I was using IDE exclusively.

The question I still have is why would stracing the DOOM sndserver make
this problem go away, if DMA to the soundcard is so time-critical?