RE: [PATCH 06/15] PCI/ACPI: Link host bridge to its ACPI fw node

From: Dan Williams
Date: Thu Sep 08 2022 - 02:05:37 EST


Robert Richter wrote:
> A lookup of a host bridge's corresponding acpi device (struct
> acpi_device) is not possible, for example:
>
> adev = ACPI_COMPANION(&host_bridge->dev);
>
> This could be useful to find a host bridge's fwnode handle and to
> determine and call additional host bridge ACPI parameters and methods
> such as HID/CID or _UID.

When is this explicitly needed. "Could be useful" is interesting, but it
needs to have a practical need.

>
> Make this work by linking the host bridge to its ACPI fw node.
>
> Signed-off-by: Robert Richter <rrichter@xxxxxxx>
> ---
> drivers/acpi/pci_root.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index d57cf8454b93..846c979e4c29 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -1083,6 +1083,7 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
> goto out_release_info;
>
> host_bridge = to_pci_host_bridge(bus->bridge);
> + host_bridge->dev.fwnode = acpi_fwnode_handle(device);
> if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
> host_bridge->native_pcie_hotplug = 0;
> if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
> --
> 2.30.2
>