1 files changed, 37 insertions, 5 deletions

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 17bed18d24ad..2aaa13150de3 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -97,16 +97,16 @@ int pci_claim_resource(struct pci_dev *dev, int resource)
 
 	root = pci_find_parent_resource(dev, res);
 	if (!root) {
-		dev_err(&dev->dev, "no compatible bridge window for %pR\n",
-			res);
+		dev_info(&dev->dev, "no compatible bridge window for %pR\n",
+			 res);
 		return -EINVAL;
 	}
 
 	conflict = request_resource_conflict(root, res);
 	if (conflict) {
-		dev_err(&dev->dev,
-			"address space collision: %pR conflicts with %s %pR\n",
-			res, conflict->name, conflict);
+		dev_info(&dev->dev,
+			 "address space collision: %pR conflicts with %s %pR\n",
+			 res, conflict->name, conflict);
 		return -EBUSY;
 	}
 
@@ -156,6 +156,38 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
 					     pcibios_align_resource, dev);
 	}
 
+	if (ret < 0 && dev->fw_addr[resno]) {
+		struct resource *root, *conflict;
+		resource_size_t start, end;
+
+		/*
+		 * If we failed to assign anything, let's try the address
+		 * where firmware left it.  That at least has a chance of
+		 * working, which is better than just leaving it disabled.
+		 */
+
+		if (res->flags & IORESOURCE_IO)
+			root = &ioport_resource;
+		else
+			root = &iomem_resource;
+
+		start = res->start;
+		end = res->end;
+		res->start = dev->fw_addr[resno];
+		res->end = res->start + size - 1;
+		dev_info(&dev->dev, "BAR %d: trying firmware assignment %pR\n",
+			 resno, res);
+		conflict = request_resource_conflict(root, res);
+		if (conflict) {
+			dev_info(&dev->dev,
+				 "BAR %d: %pR conflicts with %s %pR\n", resno,
+				 res, conflict->name, conflict);
+			res->start = start;
+			res->end = end;
+		} else
+			ret = 0;
+	}
+
 	if (!ret) {
 		res->flags &= ~IORESOURCE_STARTALIGN;
 		dev_info(&dev->dev, "BAR %d: assigned %pR\n", resno, res);