PCI: Check for PCI_HEADER_TYPE_BRIDGE equality, not bitmask
Bit 7 of the "Header Type" register indicates a multi-function device when
set. Bits 0-6 contain encoded values, where 0x1 indicates a PCI-PCI
bridge. It is incorrect to test this as though it were a mask.
For example, while the PCI 3.0 spec only defines values 0x0, 0x1, and 0x2,
it's conceivable that a future spec could define 0x3 to mean something
else; then tests for "(hdr_type & 0x7f) & PCI_HEADER_TYPE_BRIDGE" would
incorrectly succeed for this new 0x3 header type.
Test bits 0-6 of the Header Type for equality with PCI_HEADER_TYPE_BRIDGE.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/hotplug/ibmphp_pci.c b/drivers/pci/hotplug/ibmphp_pci.c
index 814cea2..5824df5 100644
--- a/drivers/pci/hotplug/ibmphp_pci.c
+++ b/drivers/pci/hotplug/ibmphp_pci.c
@@ -1119,7 +1119,7 @@
pci_bus_read_config_dword (ibmphp_pci_bus, devfn, PCI_CLASS_REVISION, &class);
debug ("hdr_type behind the bridge is %x\n", hdr_type);
- if (hdr_type & PCI_HEADER_TYPE_BRIDGE) {
+ if ((hdr_type & 0x7f) == PCI_HEADER_TYPE_BRIDGE) {
err ("embedded bridges not supported for hot-plugging.\n");
amount->not_correct = 1;
return amount;