Re: Sound error: Couldn't allocate DMA buffer

Holger Thon (Holger.Thon@uni-duisburg.de)
Sun, 11 Apr 1999 10:45:33 +0200


jumeaux lists wrote:
>
> Hi there. I keep getting this sort of thing in my syslog when
> something's trying to play through /dev/dsp:
>
> Apr 9 13:11:29 odin kernel: Sound error: Couldn't allocate DMA buffer
> Apr 9 13:12:00 odin last message repeated 48 times
> Apr 9 13:13:01 odin last message repeated 121 times
>
> ...and yet, when it happens (just now, for instance), free tells me:
>
> total used free shared buffers cached
> Mem: 95816 91756 4060 76060 4856 29388
> -/+ buffers/cache: 57512 38304
> Swap: 78864 564 78300
>
> shouldn't that be enough memory? even if the free memory isn't enough,

Due to restrictions of the ISA-Bus (where DMA actually came from), only
the first
16 MB can be allocated. In linux, dma transfers can be max. 64k at once.
However some application/other DMA device leaches this memory area, so
allocation
isn't possible.

> i'm using kernel 2.0.36 on a pentium 133; memory stats above. :) sound

When you have around 96M RAM you should upgrade to linux 2.2.x (last
stable 2.2.5).
Memory management is more efficient here. You don't need to apply the
awedrv patch,
for AWE-support is included in 2.2.5. Maybe you don't need portfw-ftp,
too, because
2.2.5 supports IP-Port-forwarding.

Maybe someone can say about the other patches?
> card is, um, i'm pretty sure it's a pci awe32 pnp soundblaster (not sure
> about the pci part offhand.) i'm using several kernel patches:
>
> subs-patch-1.37
> loose-udp-2.0.36.patch

Regards,
Holger

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