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| author | Bjorn Helgaas <bhelgaas@google.com> | 2015-12-03 20:18:18 +0100 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2015-12-11 02:38:06 +0100 |
| commit | 93de6901766c6821538b74a092e47780a9120fac (patch) | |
| tree | 05431f12c64191c2b8784afe2001b5a0f99b1a01 /drivers/pci/hotplug | |
| parent | Linux 4.4-rc2 (diff) | |
| download | linux-93de6901766c6821538b74a092e47780a9120fac.tar.xz linux-93de6901766c6821538b74a092e47780a9120fac.zip | |
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>
Diffstat (limited to 'drivers/pci/hotplug')
| -rw-r--r-- | drivers/pci/hotplug/ibmphp_pci.c | 2 |
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; |