Commit e412d63d authored May 24, 2018 by Mika Westerberg Committed by Bjorn Helgaas Jun 04, 2018

PCI: Improve "partially hidden behind bridge" log message



pci_scan_child_bus_extend() complains when we assign an unreachable
secondary bus number to a bridge.  For example, given the topology below:

  +-1b.0-[01-39]----00.0-[02-3a]--+-00.0-[03]----00.0
                                  +-01.0-[04-39]--
                                  \-02.0-[3a]----00.0

it logs the following messages:

  pci_bus 0000:3a: [bus 3a] partially hidden behind bridge 0000:02 [bus 02-39]
  pci_bus 0000:3a: [bus 3a] partially hidden behind bridge 0000:01 [bus 01-39]

These messages are incorrect (0000:02 is a bus, not a bridge) and
confusing.  Make the message more understandable:

  pci 0000:02:02.0: devices behind bridge are unusable because [bus 3a] cannot be assigned for them

Also, remove the reference to CardBus, because this issue affects all
varieties of PCI, not just CardBus.

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

parent 70f7880d

drivers/pci/probe.c

+4 −9

Original line number	Diff line number	Diff line
		@@ -1191,20 +1191,15 @@ static int pci_scan_bridge_extend(struct pci_bus bus, struct pci_dev dev,
		(is_cardbus ? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"),
		pci_domain_nr(bus), child->number);

		/* Has only triggered on CardBus, fixup is in yenta_socket */
		/* Check that all devices are accessible */
		while (bus->parent) {
		if ((child->busn_res.end > bus->busn_res.end) \|\|
		(child->number > bus->busn_res.end) \|\|
		(child->number < bus->number) \|\|
		(child->busn_res.end < bus->number)) {
		dev_info(&child->dev, "%pR %s hidden behind%s bridge %s %pR\n",
		&child->busn_res,
		(bus->number > child->busn_res.end &&
		bus->busn_res.end < child->number) ?
		"wholly" : "partially",
		bus->self->transparent ? " transparent" : "",
		dev_name(&bus->dev),
		&bus->busn_res);
		dev_info(&dev->dev, "devices behind bridge are unusable because %pR cannot be assigned for them\n",
		&child->busn_res);
		break;
		}
		bus = bus->parent;
		}

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