svgalib and dma problem

svgalib and dma problem

Post by Andrew Kieschni » Fri, 04 Oct 1996 04:00:00



Further probing of my problem with svgalib and dma led me to try accessing
a floppy while running zgv.
So I did "cat /dev/fd0 > /dev/null" and ran zgv at the same time.
Interestingly, it doesn't crash the system like everything else that uses
dma, but instead just corrupts the screen - it looks like the data being
read from the floppy ends up on the screen.

So, so far I have:
(1) ide busmastering + svgalib = crash
(2) sound + svgalib = crash
(3) floppy + svgalib = corrupted graphics

This is with a pci trio64V+ 2mb. Most video cards don't have any problems
like this, and X works fine, so I think its a problem with svgalib's
trio64V+ support, or lack thereof.
Anyone have any clues on how to fix it? I looked at the svgalib code, but
it was somewhat confusing.

later,
Andrew

 
 
 

1. svgalib + sound = hda:bad DMA status ??

Whenever I attempt to run a program that uses makes use of svgalib in
modes 640x480 or greater AND plays sound, my system crashes to a halt.
kernel.log shows this right before the crash:

Apr  7 22:50:45 moistmaster kernel: hda: bad DMA status: 0x65
Apr  7 22:50:45 moistmaster kernel: hda: dma_intr: status=0x50 {
DriveReady Seek Complete }
Apr  7 22:50:45 moistmaster kernel: hda: bad DMA status: 0x65
Apr  7 22:50:45 moistmaster kernel: hda: dma_intr: status=0x50 {
DriveReady Seek Complete }
Apr  7 22:50:45 moistmaster kernel: hda: bad DMA status: 0x65
Apr  7 22:50:45 moistmaster kernel: hda: dma_intr: status=0x50 {
DriveReady Seek Complete }
Apr  7 22:50:45 moistmaster kernel: hda: bad DMA status: 0x65
Apr  7 22:50:45 moistmaster kernel: hda: dma_intr: status=0x50 {
DriveReady Seek Complete }
Apr  7 22:50:45 moistmaster kernel: hda: disabled DMA
Apr  7 22:50:45 moistmaster kernel: ide0: reset: success        

 I'm running version 2.0.29 on a P90 with 48 megs RAM, an STB Powergraph
64v (Trio 64v+) vid card, and an SB AWE 64.  svgalib is version 1.2.10.
I've had (and ignored) this problem for some months now, and it occurred
with my old SB16 too.

I have tried recompiling svgalib with only the drivers I need, but that
didn't change anything.

Can someone supply me with a clue about what's going on?  It sure smells
like a hardware conflict of some kind, but I don't see this problem in
X, msdog or windoze.  

Thanks,

--
Bob Zimbinski


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