Re: [PATCH v2] PCI: Disable ATS via quirk before notifying IOMMU drivers

[Bjorn Helgaas]

On Tue, Mar 31, 2026 at 09:01:53AM -0700, David Matlack wrote:
> On Fri, Mar 27, 2026 at 2:17 PM David Matlack <dmatlack@xxxxxxxxxx> wrote:
> 
> >  /* AMD Raven platform iGPU */
> > -DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x15d8, quirk_amd_harvest_no_ats);
> > +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ATI, 0x15d8, quirk_amd_harvest_no_ats);
> 
> Sashiko found a bug here that would leave ATS enabled on this device:
> 
>   https://sashiko.dev/#/patchset/20260327211649.3816010-1-dmatlack%40google.com?patch=12646

Do you want to update the patch to use DECLARE_PCI_FIXUP_HEADER
instead of DECLARE_PCI_FIXUP_EARLY, as Sashiko suggested?

I don't know the IOMMU init ordering with respect to PCI enumeration,
but header fixups are run in pci_device_add() before it calls
device_add().