Booting daily snapshot 2CSNAP-20040114-2345

Jeroen koffieyahoo at
Wed Jan 21 00:07:27 PST 2004

"Jeroen" <koffieyahoo at xxxxxxxxxxx> wrote:
> > DMA is not working in the ata driver for the 645dx chipset.
> If the issue still persists at the end of this week. I might take a
> look at what is going on by comparing the code with the
> FreeBSD code.

Last night I looked into it, and the problem seems to be as follows:

1. Some of the SiS chipsets don't have an integrated south bridge, and work
with a number of different south bridges. One of these chipsets is the

2. The 645dx chipset is not recognised by the code and it therefore assumes
I have an udma33 controller.

3. Unfortunately, I have a udma133 controller (note the "1") which must be
initialised in a different way than all the other SiS dma controllers, doing
the initialisation wrong the system hangs.

This same problem also occurs in the complete FreeBSD 4 branch (4.8, 4.9,
etc). It resolved in the FreeBSD 5 branch, but of course the ata code there
is quite different.

Considering the above, I think the question I should ask is: what is the
status of ATAng, as reported in the "DragonFly Year-End summary for 2003"?

Jeroen Ketema

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