diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 0e33754..b6ceeee 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -600,7 +600,7 @@ char *resource_string(char *buf, char *end, struct resource *res,
 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
-#define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
+#define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window unset disabled]")
 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
@@ -642,6 +642,8 @@ char *resource_string(char *buf, char *end, struct resource *res,
 			p = string(p, pend, " pref", str_spec);
 		if (res->flags & IORESOURCE_WINDOW)
 			p = string(p, pend, " window", str_spec);
+		if (res->flags & IORESOURCE_UNSET)
+			p = string(p, pend, " unset", str_spec);
 		if (res->flags & IORESOURCE_DISABLED)
 			p = string(p, pend, " disabled", str_spec);
 	} else {

commit f4795a79dc370b6f4106768b16a4a9edba4df933
Author: Bjorn Helgaas <bhelgaas@google.com>
Date:   Mon Sep 24 17:15:30 2012 -0600

    PCI: Ignore BAR contents when firmware left decoding disabled

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 2396111..6926dcb 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -175,9 +175,10 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 
 	mask = type ? PCI_ROM_ADDRESS_MASK : ~0;
 
+	pci_read_config_word(dev, PCI_COMMAND, &orig_cmd);
+
 	/* No printks while decoding is disabled! */
 	if (!dev->mmio_always_on) {
-		pci_read_config_word(dev, PCI_COMMAND, &orig_cmd);
 		pci_write_config_word(dev, PCI_COMMAND,
 			orig_cmd & ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO));
 	}
@@ -211,9 +212,13 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 		if (res->flags & IORESOURCE_IO) {
 			l &= PCI_BASE_ADDRESS_IO_MASK;
 			mask = PCI_BASE_ADDRESS_IO_MASK & (u32) IO_SPACE_LIMIT;
+			if (!(orig_cmd & PCI_COMMAND_IO))
+				res->flags |= IORESOURCE_UNSET;
 		} else {
 			l &= PCI_BASE_ADDRESS_MEM_MASK;
 			mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
+			if (!(orig_cmd & PCI_COMMAND_MEM))
+				res->flags |= IORESOURCE_UNSET;
 		}
 	} else {
 		res->flags |= (l & IORESOURCE_ROM_ENABLE);
@@ -248,6 +253,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 			/* Address above 32-bit boundary; disable the BAR */
 			pci_write_config_dword(dev, pos, 0);
 			pci_write_config_dword(dev, pos + 4, 0);
+			res->flags |= IORESOURCE_UNSET;
 			region.start = 0;
 			region.end = sz64;
 			pcibios_bus_to_resource(dev, res, &region);

commit f90b82ab54efa462681d5dd99fd926f2563f7a93
Author: Bjorn Helgaas <bhelgaas@google.com>
Date:   Mon Sep 24 17:28:21 2012 -0600

    PCI: Don't claim BARs that haven't been assigned

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 81b88bd..9f9e31a 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -113,6 +113,9 @@ int pci_claim_resource(struct pci_dev *dev, int resource)
 	struct resource *res = &dev->resource[resource];
 	struct resource *root, *conflict;
 
+	if (res->flags & IORESOURCE_UNSET)
+		return 0;
+
 	root = pci_find_parent_resource(dev, res);
 	if (!root) {
 		dev_info(&dev->dev, "no compatible bridge window for %pR\n",
@@ -334,6 +337,8 @@ int pci_enable_resources(struct pci_dev *dev, int mask)
 
 		if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
 			continue;
+		if (r->flags & IORESOURCE_UNSET)
+			continue;
 		if ((i == PCI_ROM_RESOURCE) &&
 				(!(r->flags & IORESOURCE_ROM_ENABLE)))
 			continue;