[PATCH 3.19.y-ckt 074/210] PCI: Fix minimum allocation address overwrite

From: Kamal Mostafa
Date: Thu Jan 28 2016 - 21:03:33 EST


3.19.8-ckt14 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Christoph Biedl <linux-kernel.bfrz@xxxxxxxxxxxxxxxxxx>

commit 3460baa620685c20f5ee19afb6d99d26150c382c upstream.

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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/pci/bus.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index f4367a7..9021340 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -146,6 +146,8 @@ 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;

@@ -169,12 +171,12 @@ 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;
--
1.9.1