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>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/pci/hotplug/ibmphp_pci.c b/drivers/pci/hotplug/ibmphp_pci.c
index 814cea22a9fa..5824df538f72 100644
--- a/drivers/pci/hotplug/ibmphp_pci.c
+++ b/drivers/pci/hotplug/ibmphp_pci.c
@@ -1119,7 +1119,7 @@ static struct res_needed *scan_behind_bridge (struct pci_func *func, u8 busno)
                                 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;