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

From: Bjorn Helgaas
Date: Tue Aug 29 2017 - 16:50:07 EST


On Tue, Aug 29, 2017 at 01:02:41PM -0700, Samuel Sieb wrote:
> On 07/12/2017 07:56 PM, Bjorn Helgaas wrote:
> >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>
> >
> >Applied with Alex's ack to pci/virtualization for v4.14, thanks!
>
> Is there any chance of getting this into an earlier kernel? This is
> a pretty devastating bug for users! I'm currently providing patched
> kernels, but if they run upgrades and get a new kernel without
> noticing it, any filesystem they access will get completely mangled.

I assume you're looking to get this into stable kernels or distro
update kernels. I don't personally deal with either of those, but for
stable kernels, see
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/stable-kernel-rules.rst

For distro update kernels, you'd have to talk to the distro folks, and
I don't have contacts for those.

Bjorn