2006-09-21 13:33:34

by Holger Kiehl

Subject: Question regarding CONFIG_DMA_ENGINE

Hello

Is setting this option and CONFIG_NET_DMA usefull even when you do not have
the hardware?

And what hardware is required for this? Is this DMA engine located on
the network or raid card, or is this something in the chipset? Which
chipset or cards do have such an engine?

Thanks,
Holger
--

2006-09-25 22:57:11

by Brice Goglin

Subject: Re: Question regarding CONFIG_DMA_ENGINE

Holger Kiehl wrote:
> Hello
>
> Is setting this option and CONFIG_NET_DMA usefull even when you do not
> have
> the hardware?
>
> And what hardware is required for this? Is this DMA engine located on
> the network or raid card, or is this something in the chipset? Which
> chipset or cards do have such an engine?
>
> Thanks,
> Holger

I guess the option is completely useless without such hardware.

For now, you need a Intel E5000 chipset (Blackford and co.). It exports
a special PCI device (id 8086:1a38) for DMA. No other device is
supported so far, but some Raid stuff have been proposed recently IIRC.

Brice