[PATCH] Fix restore of 64-bit PCI BAR's

For 64-bit BAR[i] only pci_dev->resource[i] is valid, ->resource[i+1]
slot is unused and contains zeroes in all fields.

So when we update a PCI BAR, all we need is just to check that we're
going to update a _valid_ resource.

Also make sure to write high bits - use "x >> 16 >> 16" (rather than the
simpler ">> 32") to avoid warnings on 32-bit architectures where we're
not going to have any high bits.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 878fd0a65c02..589486704ce3 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -33,6 +33,11 @@ pci_update_resource(struct pci_dev *dev, struct resource *res, int resno)
         u32 new, check, mask;
         int reg;
 
+        /* Ignore resources for unimplemented BARs and unused resource slots
+           for 64 bit BARs. */
+        if (!res->flags)
+                return;
+
         pcibios_resource_to_bus(dev, &region, res);
 
         pr_debug("  got res [%lx:%lx] bus [%lx:%lx] flags %lx for "
@@ -67,7 +72,7 @@ pci_update_resource(struct pci_dev *dev, struct resource *res, int resno)
 
         if ((new & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
             (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64)) {
-                new = 0; /* currently everyone zeros the high address */
+                new = region.start >> 16 >> 16;
                 pci_write_config_dword(dev, reg + 4, new);
                 pci_read_config_dword(dev, reg + 4, &check);
                 if (check != new) {