The root port used for PCIe tunneling is the root of the hierarchy used for all PCIe devices that are connected downstream. Tunnels are created and destroyed by the USB4 SW CM. So this port should be marked as external meaning all devices connected to it are appropriately marked as removable for downstream drivers to detect. This can be done by looking for the device property specified in the ACPI tables `usb4-host-interface`. Suggested-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> Link: https://docs.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports#mapping-native-protocols-pcie-displayport-tunneled-through-usb4-to-usb4-host-routers Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> --- drivers/pci/pci-acpi.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index a42dbf448860..695dbd88b8b7 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -1335,12 +1335,21 @@ static void pci_acpi_optimize_delay(struct pci_dev *pdev, static void pci_acpi_set_external_facing(struct pci_dev *dev) { - u8 val; + u8 val = 0; if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) return; - if (device_property_read_u8(&dev->dev, "ExternalFacingPort", &val)) - return; + device_property_read_u8(&dev->dev, "ExternalFacingPort", &val); + + /* check for root port for PCIe tunnels on integrated controllers */ + if (!val) { + struct acpi_device *adev = ACPI_COMPANION(&dev->dev); + + if (!adev) + return; + val = fwnode_property_present(acpi_fwnode_handle(adev), + "usb4-host-interface"); + } /* * These root ports expose PCIe (including DMA) outside of the -- 2.34.1
