PCI: Simplify disconnected marking (a50ac6bf) · Commits · 戴 / test

Commit ("PCI: Add device disconnected state") iterates over the devices on a parent bus, marks each as disconnected, then marks each device's children as disconnected using pci_walk_bus(). The same can be achieved more succinctly by calling pci_walk_bus() on the parent bus. Moreover, this does not need to wait until acquiring pci_lock_rescan_remove(), so move it out of that critical section. The critical section in err.c contains a pci_dev_get() / pci_dev_put() pair which was apparently copy-pasted from pciehp_pci.c. In the latter it serves the purpose of holding the struct pci_dev in place until the Command register is updated. err.c doesn't do anything like that, hence the pair is unnecessary. Remove it. Signed-off-by:

Lukas Wunner <lukas@wunner.de> Signed-off-by:

Bjorn Helgaas <bhelgaas@google.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Oza Pawandeep <poza@codeaurora.org> Cc: Sinan Kaya <okaya@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/pci/hotplug/pciehp_pci.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -74,6 +74,9 @@ void pciehp_unconfigure_device(struct slot *p_slot)
		__func__, pci_domain_nr(parent), parent->number);
		pciehp_get_adapter_status(p_slot, &presence);

		if (!presence)
		pci_walk_bus(parent, pci_dev_set_disconnected, NULL);

		pci_lock_rescan_remove();

		/*
		@@ -85,12 +88,6 @@ void pciehp_unconfigure_device(struct slot *p_slot)
		list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
		bus_list) {
		pci_dev_get(dev);
		if (!presence) {
		pci_dev_set_disconnected(dev, NULL);
		if (pci_has_subordinate(dev))
		pci_walk_bus(dev->subordinate,
		pci_dev_set_disconnected, NULL);
		}
		pci_stop_and_remove_bus_device(dev);
		/*
		* Ensure that no new Requests will be generated from

drivers/pci/pcie/err.c

+2 −6

Original line number	Diff line number	Diff line
		@@ -292,17 +292,13 @@ void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service)
		udev = dev->bus->self;

		parent = udev->subordinate;
		pci_walk_bus(parent, pci_dev_set_disconnected, NULL);

		pci_lock_rescan_remove();
		pci_dev_get(dev);
		list_for_each_entry_safe_reverse(pdev, temp, &parent->devices,
		bus_list) {
		pci_dev_get(pdev);
		pci_dev_set_disconnected(pdev, NULL);
		if (pci_has_subordinate(pdev))
		pci_walk_bus(pdev->subordinate,
		pci_dev_set_disconnected, NULL);
		pci_stop_and_remove_bus_device(pdev);
		pci_dev_put(pdev);
		}

		result = reset_link(udev, service);

Admin message