PCI: checking busn_res in pci_scan_root_bus() (4d99f524) · Commits · 戴 / test

Some callers do not supply the bus number aperture, usually because they do not know the end. In this case, we assume the aperture extends from the root bus number to bus 255, scan the bus, and shrink the bus number resource so it ends at the largest bus number we found. This is obviously not correct because the actual end of the aperture may well be larger than the largest bus number we found. But I guess it's all we have for now. Also print out one info about that, so we could find out which path does not have busn_res in resources list. [bhelgaas: changelog, _safe iterator unnecessary, use %pR format for bus] Signed-off-by:

Yinghai Lu <yinghai@kernel.org>

drivers/pci/probe.c

+21 −1

Original line number	Diff line number	Diff line
		@@ -1788,13 +1788,33 @@ void pci_bus_release_busn_res(struct pci_bus *b)
		struct pci_bus * __devinit pci_scan_root_bus(struct device *parent, int bus,
		struct pci_ops ops, void sysdata, struct list_head *resources)
		{
		struct pci_host_bridge_window *window;
		bool found = false;
		struct pci_bus *b;
		int max;

		list_for_each_entry(window, resources, list)
		if (window->res->flags & IORESOURCE_BUS) {
		found = true;
		break;
		}

		b = pci_create_root_bus(parent, bus, ops, sysdata, resources);
		if (!b)
		return NULL;

		b->busn_res.end = pci_scan_child_bus(b);
		if (!found) {
		dev_info(&b->dev,
		"No busn resource found for root bus, will use [bus %02x-ff]\n",
		bus);
		pci_bus_insert_busn_res(b, bus, 255);
		}

		max = pci_scan_child_bus(b);

		if (!found)
		pci_bus_update_busn_res_end(b, max);

		pci_bus_add_devices(b);
		return b;
		}

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