Re: 2.1.111: IDE DMA disabled?

Linus Torvalds (
Tue, 28 Jul 1998 10:32:37 -0700 (PDT)

On Mon, 27 Jul 1998, Daniel Egger wrote:

> On Sun, 26 Jul 1998, Linus Torvalds wrote:
> >completely bogus to me. If you're running Win3.11, the BIOS will have done
> >the same thing, and I know win3.11 doesn't use DMA in its native driver.
> >And I bet they tested that configuration.
> I bet they hadn't the chance to do so.... DMA respective PIO 4 has been
> introduced quite a while after Win 3.11 was released......

Umm.. Do you _really_ think that people would release a new BIOS or a new
harddisk without testing that it works with Win-3.11?

The point being that Win-3.11 doesn't use (U)DMA (exactly because it was
released long before (U)DMA was), but the manufacturer is bound to have
tested their hardware with it.

Ergo, we can pretty much depend on the fact that no (U)DMA setup can ever
_require_ us to use DMA - whatever the BIOS has done.

In short, people arguing that we have to use DMA because the BIOS says it
support it are making up a completely bogus argument that doesn't hold an
ounce of water.

Can we stop this now, and make sure that the Linux defaults are sane?


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