Let me preface this by saying, I am no expert, I just did some googling,
and I am most likely getting the info wrong.

BUT, from what I found, it looks like the kernel thinks that the IOMMU
is setup wrong in the BIOS so it makes some changes at startup. I think
that is what the "Using GART IOMMU" and "Reserving 64MB of IOMMU area in
the AGP aperture" are saying. The problem comes in when we supsend.
During resume this 'fixing' doesn't occur again for some reason and
there is a mismatch between the computer state before suspend and after
suspend. Thus, "RUINS FILESYSTEM".

I wonder if the "iommu=soft" is a case of throwing the baby out with the
bath water? I don't know what the hardware IOMMU does exactly, but we
probably want to keep it around since AMD took the time to implement on
their chips.

Now, I THINK, this aperture is fixing things for AGP cards, which most
of us probably don't have. So long story short, I looked through the
iommu settings and there is "iommu=noagp". I have also seen
recomendations of "iommu=noaperture" and "iommu=memaper=3" (or
"iommu=memaper=1" or "iommu=memaper=2")

I can't go through losing my data again, so is there someone willing to
try these out as alternatives to "iommu=soft"? I give no guarantees.

-- 
Hardy -- Suspend RUINS FILESYSTEM
https://bugs.launchpad.net/bugs/203537
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