Re: 2.6.13-rc6-git10 test report [x86_64]

[Andi Kleen <ak@suse.de>]

On Thu, Aug 18, 2005 at 03:52:13PM -0700, Sean Bruno wrote:
> With earlier kernels(2.6.11) I was able to boot my machine with ACPI
> enabled, but most devices(sound, onboard ethernet, SATA controllers,
> USB) were unusuable but they were detected.  I was able to work around
> this issue by disabling ACPI in my system BIOS.  

Keeping it on and using pci=noacpi might be better.

> available.  Since 2.6.12, when I re-activate ACPI in my system BIOS, I
> can't boot my machine as it gives me an error about no IOMMU and having
> 6GB of RAM.  This error was not listed in the dmesg posted before as I
> can't boot my machine past this error.
> 
> Here is the exact output when booting 2.6.13 with ACPI enabled:
> 
> Decompressing Linux ... Done
> Booting the kernel
> PCI-DMA:  More that 4GB of RAM and no IOMMU
> PCI-DMA:  32bit PCI IO may malfunction.<6>PCI-DMA:  Disabling IOMMU

This has nothing to do with ACPI. The problem here is that you 
didn't enable the IOMMU code in the kernel .config

-Andi