DMA

[Jeff Waugh]

<quote who="Sean Hammond">

> >If DMA is disabled by default, then you're running the risk of crashing
> >or damaging your machine by enabling it.
> 
> So I've heard. Does this mean that Windows enables DMA by default on many
> such systems and runs the risk, whereas Ubuntu/Debian/(Linux?) are more
> cautious?

Here are two reasons why DMA might be disabled:

 1) The hardware does not function correctly, or causes errors when DMA is
 enabled

 2) The drivers do not function correctly, or cause errors when DMA is
 enabled

In the case of (2), then yes, Windows may enable DMA by default on the same
device. But it would not be a good idea for us to enable it, or let a user
think that he/she should enable it. After all, how many users know what DMA
really means, beyond "DMA go faster!"?

Scott isn't talking about fixing problems like lack of X configuration tools
though - he's talking about the appropriateness and dangers of exposing the
underlying machinery of the computer to users who don't understand it... and
don't care to understand it.

DMA really is a more/less magic setting. Why burden the user with that
choice?

- Jeff

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GUADEC 2006: Vilanova i la Geltrú, Spain            http://2006.guadec.org/
 
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