PCI: Fix minimum allocation address overwrite

[ Upstream commit 3460baa620685c20f5ee19afb6d99d26150c382c ]

Commit 36e097a8a297 ("PCI: Split out bridge window override of minimum
allocation address") claimed to do no functional changes but unfortunately
did: The "min" variable is altered.  At least the AVM A1 PCMCIA adapter was
no longer detected, breaking ISDN operation.

Use a local copy of "min" to restore the previous behaviour.

[bhelgaas: avoid gcc "?:" extension for portability and readability]
Fixes: 36e097a8a297 ("PCI: Split out bridge window override of minimum allocation address")
Signed-off-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org      # v3.14+
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index d3346d2..89b3bef 100644 (file)
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -140,6 +140,8 @@ static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
        type_mask |= IORESOURCE_TYPE_BITS;
 
        pci_bus_for_each_resource(bus, r, i) {
+               resource_size_t min_used = min;
+
                if (!r)
                        continue;
 
@@ -163,12 +165,12 @@ static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
                 * overrides "min".
                 */
                if (avail.start)
-                       min = avail.start;
+                       min_used = avail.start;
 
                max = avail.end;
 
                /* Ok, try it out.. */
-               ret = allocate_resource(r, res, size, min, max,
+               ret = allocate_resource(r, res, size, min_used, max,
                                        align, alignf, alignf_data);
                if (ret == 0)
                        return 0;