PCI: remove transparent bridge sizing

Remove transparent bridge sizing.

Due to code in pci_read_bridge_bases() [drivers/pci/probe.c] the child
bus of a transparent bridge already has access to the parent bus
resources so transparent bridge sizing appears unnecessary.  The bridge
sizing includes alignment and granularity adjustments that can cause
significantly more memory to be reserved from the parant bus than
required by devices on the child bus and allotted by _CRS.

Signed-off-by: Gary Hade <gary.hade@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 5e5191ec8de..401e03c920b 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -472,7 +472,12 @@ void pci_bus_size_bridges(struct pci_bus *bus)
                 break;
 
         case PCI_CLASS_BRIDGE_PCI:
+                /* don't size subtractive decoding (transparent)
+                 * PCI-to-PCI bridges */
+                if (bus->self->transparent)
+                        break;
                 pci_bridge_check_ranges(bus);
+                /* fall through */
         default:
                 pbus_size_io(bus);
                 /* If the bridge supports prefetchable range, size it