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authorLinus Torvalds <torvalds@linux-foundation.org>2015-05-29 17:09:39 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-05-29 17:09:39 -0700
commitaaa20fc23341be3df7b17810e330f12244abcf29 (patch)
tree2c637d9ef87a6595beacc8ff556705db7bf071b7 /arch
parent1be44e234b672eadbf1d96eb172ef21f5ff6a2c9 (diff)
parentdc4fdaf0e4839109169d8261814813816951c75f (diff)
Merge tag 'acpi-pci-4.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull PCI / ACPI fix from Rafael Wysocki: "This fixes a bug uncovered by a recent driver core change that modified the implementation of the ACPI_COMPANION_SET() macro to strictly rely on its second argument to be either NULL or a valid pointer to struct acpi_device. As it turns out, pcibios_root_bridge_prepare() on x86 and ia64 works with the assumption that the only code path calling pci_create_root_bus() is pci_acpi_scan_root() and therefore the sysdata argument passed to it will always match the expectations of pcibios_root_bridge_prepare(). That need not be the case, however, and in particular it is not the case for the Xen pcifront driver that passes a pointer to its own private data strcture as sysdata to pci_scan_bus_parented() which then passes it to pci_create_root_bus() and it ends up being used incorrectly by pcibios_root_bridge_prepare()" * tag 'acpi-pci-4.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PCI / ACPI: Do not set ACPI companions for host bridges with parents
Diffstat (limited to 'arch')
-rw-r--r--arch/ia64/pci/pci.c13
-rw-r--r--arch/x86/pci/acpi.c13
2 files changed, 20 insertions, 6 deletions
diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index d4e162d35b34..7cc3be9fa7c6 100644
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -478,9 +478,16 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
{
- struct pci_controller *controller = bridge->bus->sysdata;
-
- ACPI_COMPANION_SET(&bridge->dev, controller->companion);
+ /*
+ * We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
+ * here, pci_create_root_bus() has been called by someone else and
+ * sysdata is likely to be different from what we expect. Let it go in
+ * that case.
+ */
+ if (!bridge->dev.parent) {
+ struct pci_controller *controller = bridge->bus->sysdata;
+ ACPI_COMPANION_SET(&bridge->dev, controller->companion);
+ }
return 0;
}
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index d93963340c3c..14a63ed6fe09 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -482,9 +482,16 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
{
- struct pci_sysdata *sd = bridge->bus->sysdata;
-
- ACPI_COMPANION_SET(&bridge->dev, sd->companion);
+ /*
+ * We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
+ * here, pci_create_root_bus() has been called by someone else and
+ * sysdata is likely to be different from what we expect. Let it go in
+ * that case.
+ */
+ if (!bridge->dev.parent) {
+ struct pci_sysdata *sd = bridge->bus->sysdata;
+ ACPI_COMPANION_SET(&bridge->dev, sd->companion);
+ }
return 0;
}