[bugzilla-daemon at bugzilla.kernel.org: [Bug 209149] New: "iommu/vt-d: Enable PCI ACS for platform opt in hint" makes NVMe config space not accessible after S3]

[Raj, Ashok]

On Wed, Sep 23, 2020 at 12:45:11PM -0700, Rajat Jain wrote:
> On Wed, Sep 23, 2020 at 9:19 AM Raj, Ashok <ashok.raj at intel.com> wrote:
> >
> > Hi Bjorn
> >
> >
> > On Wed, Sep 23, 2020 at 11:03:27AM -0500, Bjorn Helgaas wrote:
> > > [+cc IOMMU and NVMe folks]
> > >
> > > Sorry, I forgot to forward this to linux-pci when it was first
> > > reported.
> > >
> > > Apparently this happens with v5.9-rc3, and may be related to
> > > 50310600ebda ("iommu/vt-d: Enable PCI ACS for platform opt in hint"),
> > > which appeared in v5.8-rc3.
> > >
> > > There are several dmesg logs and proposed patches in the bugzilla, but
> > > no analysis yet of what the problem is.  From the first dmesg
> > > attachment (https://bugzilla.kernel.org/attachment.cgi?id=292327):
> >
> > We have been investigating this internally as well. It appears maybe the
> > specupdate for Cometlake is missing the errata documention. The offsets
> > were wrong in some of them, and if its the same issue its likely cause.
> 
> Can you please also confirm if errata applies to Tigerlake ?
> 

We confirmed ICL/TGL isn't affected.