[+cc Rob]
On Mon, Sep 13, 2021 at 06:23:59PM +0100, Jean-Philippe Brucker wrote:
> Commit 375553a93201 ("PCI: Setup ACPI fwnode early and at the same time
> with OF") added a call to pci_set_acpi_fwnode() in pci_setup_device(),
> which unconditionally clears any fwnode previously set by
> pci_set_of_node().
>
> pci_set_acpi_fwnode() looks for ACPI_COMPANION(), which only returns the
> existing fwnode if it was set by ACPI_COMPANION_SET(). If it was set by
> OF instead, ACPI_COMPANION() returns NULL and pci_set_acpi_fwnode()
> accidentally clears the fwnode. To fix this, look for any fwnode instead
> of just ACPI companions.
>
> Fixes: 375553a93201 ("PCI: Setup ACPI fwnode early and at the same time with OF")
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> ---
> This fixes boot of virtio-iommu under OF on v5.15-rc1
> ---
> drivers/pci/pci-acpi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index a1b1e2a01632..483a9e50f6ca 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -937,7 +937,7 @@ static struct acpi_device *acpi_pci_find_companion(struct device *dev);
>
> void pci_set_acpi_fwnode(struct pci_dev *dev)
> {
> - if (!ACPI_COMPANION(&dev->dev) && !pci_dev_is_added(dev))
> + if (!dev->dev.fwnode && !pci_dev_is_added(dev))
I don't doubt that this is correct, but it seems excessively subtle,
like we're violating some layering or something.
Rafael, Rob, is there anything better we can do here?
> ACPI_COMPANION_SET(&dev->dev,
> acpi_pci_find_companion(&dev->dev));
> }
> --
> 2.33.0
>
