Re: [regression, bisected, pci/iommu] Bug 216865 - Black screen when amdgpu started during 6.2-rc1 boot with AMD IOMMU enabled

[Jason Gunthorpe]

On Wed, Jan 11, 2023 at 11:16:32AM +0800, Baolu Lu wrote:
> On 2023/1/10 21:25, Jason Gunthorpe wrote:
> > > +       } else {
> > > +               if (!pdev->bus->self ||
> > > +                   !pci_acs_path_enabled(pdev->bus->self, NULL,
> > > +                                         PCI_ACS_RR | PCI_ACS_UF))
> > > +                       return -EINVAL;
> > > +       }
> > Why would these be exclusive? Both the path and endpoint needs to be
> > checked
> 
> If the device is not an MFD, do we still need to check the ACS on it?
> Perhaps I didn't get your point correctly.

It always needs to check the path

Jason