Commit 5396956c authored Jun 22, 2020 by Mika Westerberg Committed by Bjorn Helgaas Jun 30, 2020

PCI: Make pcie_find_root_port() work for Root Ports

Commit 6ae72bfa ("PCI: Unify pcie_find_root_port() and
pci_find_pcie_root_port()") broke acpi_pci_bridge_d3() because calling
pcie_find_root_port() on a Root Port returned NULL when it should return
the Root Port, which in turn broke power management of PCIe hierarchies.

Rework pcie_find_root_port() so it returns its argument when it is already
a Root Port.

[bhelgaas: test device only once, test for PCIe]
Fixes: 6ae72bfa ("PCI: Unify pcie_find_root_port() and pci_find_pcie_root_port()")
Link: https://lore.kernel.org/r/20200622161248.51099-1-mika.westerberg@linux.intel.com


Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

parent b3a9e3b9

include/linux/pci.h

+5 −6

Original line number	Diff line number	Diff line
		@@ -2169,12 +2169,11 @@ static inline int pci_pcie_type(const struct pci_dev *dev)
		*/
		static inline struct pci_dev pcie_find_root_port(struct pci_dev dev)
		{
		struct pci_dev *bridge = pci_upstream_bridge(dev);

		while (bridge) {
		if (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT)
		return bridge;
		bridge = pci_upstream_bridge(bridge);
		while (dev) {
		if (pci_is_pcie(dev) &&
		pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
		return dev;
		dev = pci_upstream_bridge(dev);
		}

		return NULL;

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