On Wed, Aug 31, 2022 at 10:15:54AM +0200, 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. > > Make this work by linking the host bridge to its ACPI fw node. s/acpi device/ACPI device/ to match other "ACPI" usage s/fw node/fwnode/ (if it should match "fwnode handle" above) I guess this patch makes ACPI_COMPANION() work where it didn't before, right? E.g., the two ACPI_COMPANION() uses added by this series (cxl_find_next_rch() and cxl_restricted_host_probe()). I'm not really clear on the strategy of when we should use acpi_device vs acpi_handle, but does this mean there's code in places like pci_root.c that should be reworked to take advantage of this? That code evaluates _DSM and _OSC, but I think it currently uses acpi_handle for that. Bjorn