c1976a4248
[ Upstream commit f3380cac0c0b3a6f49ab161e2a057c363962f48d ] If protocol tunnels are already up when the driver is loaded, for instance if the boot firmware implements connection manager of its own, runtime PM reference count of the consumer devices behind the tunnel might have been increased already before the device link is created but the supplier device runtime PM reference count is not. This leads to a situation where the supplier (the Thunderbolt driver) can runtime suspend even if it should not because the corresponding protocol tunnel needs to be up causing the devices to be removed from the corresponding native bus. Prevent this from happening by making both sides of the link runtime PM active briefly. The pm_runtime_put() for the consumer (PCIe root/downstream port, xHCI) then allows it to runtime suspend again but keeps the supplier runtime resumed the whole time it is runtime active. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
131 lines
3.4 KiB
C
131 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ACPI support
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*
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* Copyright (C) 2020, Intel Corporation
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* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
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*/
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#include <linux/acpi.h>
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#include <linux/pm_runtime.h>
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#include "tb.h"
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static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
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void **return_value)
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{
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struct fwnode_reference_args args;
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struct fwnode_handle *fwnode;
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struct tb_nhi *nhi = data;
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struct acpi_device *adev;
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struct pci_dev *pdev;
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struct device *dev;
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int ret;
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if (acpi_bus_get_device(handle, &adev))
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return AE_OK;
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fwnode = acpi_fwnode_handle(adev);
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ret = fwnode_property_get_reference_args(fwnode, "usb4-host-interface",
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NULL, 0, 0, &args);
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if (ret)
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return AE_OK;
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/* It needs to reference this NHI */
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if (nhi->pdev->dev.fwnode != args.fwnode)
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goto out_put;
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/*
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* Try to find physical device walking upwards to the hierarcy.
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* We need to do this because the xHCI driver might not yet be
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* bound so the USB3 SuperSpeed ports are not yet created.
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*/
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dev = acpi_get_first_physical_node(adev);
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while (!dev) {
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adev = adev->parent;
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if (!adev)
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break;
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dev = acpi_get_first_physical_node(adev);
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}
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if (!dev)
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goto out_put;
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/*
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* Check that the device is PCIe. This is because USB3
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* SuperSpeed ports have this property and they are not power
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* managed with the xHCI and the SuperSpeed hub so we create the
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* link from xHCI instead.
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*/
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while (dev && !dev_is_pci(dev))
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dev = dev->parent;
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if (!dev)
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goto out_put;
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/*
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* Check that this actually matches the type of device we
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* expect. It should either be xHCI or PCIe root/downstream
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* port.
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*/
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pdev = to_pci_dev(dev);
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if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI ||
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(pci_is_pcie(pdev) &&
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(pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
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pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM))) {
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const struct device_link *link;
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/*
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* Make them both active first to make sure the NHI does
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* not runtime suspend before the consumer. The
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* pm_runtime_put() below then allows the consumer to
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* runtime suspend again (which then allows NHI runtime
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* suspend too now that the device link is established).
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*/
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pm_runtime_get_sync(&pdev->dev);
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link = device_link_add(&pdev->dev, &nhi->pdev->dev,
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DL_FLAG_AUTOREMOVE_SUPPLIER |
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DL_FLAG_RPM_ACTIVE |
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DL_FLAG_PM_RUNTIME);
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if (link) {
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dev_dbg(&nhi->pdev->dev, "created link from %s\n",
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dev_name(&pdev->dev));
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} else {
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dev_warn(&nhi->pdev->dev, "device link creation from %s failed\n",
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dev_name(&pdev->dev));
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}
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pm_runtime_put(&pdev->dev);
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}
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out_put:
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fwnode_handle_put(args.fwnode);
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return AE_OK;
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}
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/**
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* tb_acpi_add_links() - Add device links based on ACPI description
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* @nhi: Pointer to NHI
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*
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* Goes over ACPI namespace finding tunneled ports that reference to
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* @nhi ACPI node. For each reference a device link is added. The link
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* is automatically removed by the driver core.
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*/
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void tb_acpi_add_links(struct tb_nhi *nhi)
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{
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acpi_status status;
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if (!has_acpi_companion(&nhi->pdev->dev))
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return;
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/*
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* Find all devices that have usb4-host-controller interface
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* property that references to this NHI.
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*/
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status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 32,
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tb_acpi_add_link, NULL, nhi, NULL);
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if (ACPI_FAILURE(status))
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dev_warn(&nhi->pdev->dev, "failed to enumerate tunneled ports\n");
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}
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