From 93de6901766c6821538b74a092e47780a9120fac Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 3 Dec 2015 13:18:18 -0600 Subject: 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 --- drivers/pci/hotplug/ibmphp_pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/pci/hotplug/ibmphp_pci.c') 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; -- cgit v1.2.3