tree 05431f12c64191c2b8784afe2001b5a0f99b1a01
parent 1ec218373b8ebda821aec00bb156a9c94fad9cd4
author Bjorn Helgaas <bhelgaas@google.com> 1449170298 -0600
committer Bjorn Helgaas <bhelgaas@google.com> 1449797886 -0600

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>