x86/ioapic: Ignore root bridges without a companion ACPI device
Some PCI root bridges don't have a corresponding ACPI device.
This can be the case on some old platforms. Don't call acpi_ioapic_add()
on these bridges because they can't support ioapic hotplug.
Reported-and-tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bhelgaas@google.com
Cc: helgaas@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1473522046-31329-1-git-send-email-rui.y.wang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index ec538d3..f30ca75 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1855,7 +1855,10 @@
list_for_each_entry(root_bus, &pci_root_buses, node) {
pci_assign_unassigned_root_bus_resources(root_bus);
- acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));
+
+ /* Make sure the root bridge has a companion ACPI device: */
+ if (ACPI_HANDLE(root_bus->bridge))
+ acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));
}
}