Commit b6f6d56c authored Aug 17, 2017 by Thierry Reding Committed by David S. Miller Aug 18, 2017

PCI: Allow PCI express root ports to find themselves



If the pci_find_pcie_root_port() function is called on a root port
itself, return the root port rather than NULL.

This effectively reverts commit 0e405232 ("PCI: fix oops when
try to find Root Port for a PCI device") which added an extra check
that would now be redundant.

Fixes: a99b646a ("PCI: Disable PCIe Relaxed Ordering if unsupported")
Fixes: c56d4450 ("PCI: Turn off Request Attributes to avoid Chelsio T5 Completion erratum")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent cdbeb633

drivers/pci/pci.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -514,7 +514,7 @@ EXPORT_SYMBOL(pci_find_resource);
		*/
		struct pci_dev pci_find_pcie_root_port(struct pci_dev dev)
		{
		struct pci_dev bridge, highest_pcie_bridge = NULL;
		struct pci_dev bridge, highest_pcie_bridge = dev;

		bridge = pci_upstream_bridge(dev);
		while (bridge && pci_is_pcie(bridge)) {
		@@ -522,11 +522,10 @@ struct pci_dev pci_find_pcie_root_port(struct pci_dev dev)
		bridge = pci_upstream_bridge(bridge);
		}

		if (highest_pcie_bridge &&
		pci_pcie_type(highest_pcie_bridge) == PCI_EXP_TYPE_ROOT_PORT)
		return highest_pcie_bridge;

		if (pci_pcie_type(highest_pcie_bridge) != PCI_EXP_TYPE_ROOT_PORT)
		return NULL;

		return highest_pcie_bridge;
		}
		EXPORT_SYMBOL(pci_find_pcie_root_port);

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