Commit 1a4b1a41 authored Sep 13, 2011 by Benjamin Herrenschmidt Committed by Linus Torvalds Sep 13, 2011

pci: Don't crash when reading mpss from root complex



In pcie_find_smpss(), we have the following statement:

 	if (dev->is_hotplug_bridge && (!list_is_singular(&dev->bus->devices) ||
	    dev->bus->self->pcie_type != PCI_EXP_TYPE_ROOT_PORT))

The problem is that at least on my machine, this gets called for the
root complex (virtual P2P bridge), and dev->bus->self is NULL since
the parent bus for this is not itself anchor to a PCI device.

This adds the necessary NULL check.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Jon Mason <mason@myri.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 2f4d3218

drivers/pci/probe.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1351,7 +1351,8 @@ static int pcie_find_smpss(struct pci_dev dev, void data)
		* will occur as normal.
		*/
		if (dev->is_hotplug_bridge && (!list_is_singular(&dev->bus->devices) \|\|
		dev->bus->self->pcie_type != PCI_EXP_TYPE_ROOT_PORT))
		(dev->bus->self &&
		dev->bus->self->pcie_type != PCI_EXP_TYPE_ROOT_PORT)))
		*smpss = 0;

		if (*smpss > dev->pcie_mpss)

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