Re: 2.6.22-rc6-mm1 Intel DMAR crash on AMD x86_64

[Zan Lynx <zlynx@acm.org>]

On Thu, 2007-06-28 at 03:43 -0700, Andrew Morton wrote:
> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.22-rc6/2.6.22-rc6-mm1/

> +intel-iommu-dmar-detection-and-parsing-logic.patch
> +intel-iommu-pci-generic-helper-function.patch
> +intel-iommu-pci-generic-helper-function-fix.patch
> +intel-iommu-clflush_cache_range-now-takes-size-param.patch
> +intel-iommu-iova-allocation-and-management-routines.patch
> +intel-iommu-iova-allocation-and-management-routines-fix.patch
> +intel-iommu-iova-allocation-and-management-routines-fix-2.patch
> +intel-iommu-intel-iommu-driver.patch
> +intel-iommu-intel-iommu-driver-fix.patch
> +intel-iommu-intel-iommu-driver-fix-2.patch
> +intel-iommu-avoid-memory-allocation-failures-in-dma-map-api-calls.patch
> +intel-iommu-intel-iommu-cmdline-option-forcedac.patch
> +intel-iommu-dmar-fault-handling-support.patch
> +intel-iommu-iommu-gfx-workaround.patch
> +intel-iommu-iommu-floppy-workaround.patch
> +intel-iommu-iommu-floppy-workaround-fix.patch
> +intel-iommu-iommu-floppy-workaround-fix-fix.patch
> 
>  Intel IOMMU support

I believe the above patch set is causing the problem.  On my first try
with rc6-mm1 I said Yes to the CONFIG_DMAR options. (I'm nearly as good
as random option selection :-)

The system panicked during boot, I believe it was trying to detect an
Intel IOMMU.  Later when I have a camera, I will try to post a
screenshot of the backtrace. (I can't seem to get netconsole to work on
boot, only in a module).

When I recompiled without DMAR set, things seem to be working great.  I
seem to be getting better disk read throughput than rc3-mm1, by the way.

This laptop is an AMD Athlon64 on a NForce3 running a 64-bit Gentoo
build.

I'll provide more details on request, and when I get the chance.  This
is a heads-up on the BUG in case someone has an "ah ha!" moment.
-- 
Zan Lynx <zlynx@acm.org>

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