Re: [PATCH v2] PCI: Add ATS-disable quirk for AMD Stoney GPUs

From: Bjorn Helgaas
Date: Thu Jun 15 2017 - 15:16:03 EST


On Thu, Jun 15, 2017 at 04:04:21PM +0200, Joerg Roedel wrote:
> Hi Bjorn,
>
> On Fri, Apr 07, 2017 at 04:32:18PM +0200, Joerg Roedel wrote:
> > From: Joerg Roedel <jroedel@xxxxxxx>
> >
> > ATS is broken on this hardware and causes IOMMU stalls and
> > system failure. Disable ATS on these devices to make them
> > usable again with IOMMU enabled.
> >
> > Note that the commit in the Fixes-tag is not buggy, it
> > just uncovers the problem in the hardware by increasing
> > the ATS-flush rate.
> >
> > Fixes: b1516a14657a ('iommu/amd: Implement flush queue')
> > Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
> > ---
> > drivers/pci/quirks.c | 19 +++++++++++++++++++
> > 1 file changed, 19 insertions(+)
>
> Any more objections on this patch? Please let me know if you want to
> have something changed.

It was marked "superseded" in patchwork and thus off my radar. I
don't remember if I did that or why. I changed it back to "New" so I
won't forget about it.

You mention (May 24) the original bug report. Can you include the URL
for that?

I admit I just don't have warm fuzzies that the problem is well
understood.

Bjorn