Re: [PATCH v2] ACPI: VIOT: Fix ACS setup

[Rafael J. Wysocki]

On Thu, Jun 30, 2022 at 11:59 AM Jean-Philippe Brucker
<jean-philippe@xxxxxxxxxx> wrote:
>
> On Thu, Jun 30, 2022 at 11:40:59AM +0200, Eric Auger wrote:
> > Currently acpi_viot_init() gets called after the pci
> > device has been scanned and pci_enable_acs() has been called.
> > So pci_request_acs() fails to be taken into account leading
> > to wrong single iommu group topologies when dealing with
> > multi-function root ports for instance.
> >
> > We cannot simply move the acpi_viot_init() earlier, similarly
> > as the IORT init because the VIOT parsing relies on the pci
> > scan. However we can detect VIOT is present earlier and in
> > such a case, request ACS. Introduce a new acpi_viot_early_init()
> > routine that allows to call pci_request_acs() before the scan.
> >
> > While at it, guard the call to pci_request_acs() with #ifdef
> > CONFIG_PCI.
> >
> > Fixes: 3cf485540e7b ("ACPI: Add driver for the VIOT table")
> > Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
> > Reported-by: Jin Liu <jinl@xxxxxxxxxx>
>
> Reviewed-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> Tested-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>

Applied as 5.20 material, thanks!