Index: uspace/drv/bus/pci/pciintel/pci.c
===================================================================
--- uspace/drv/bus/pci/pciintel/pci.c	(revision c67dbd622a32b92e827b239c60b0a0e72d711a01)
+++ uspace/drv/bus/pci/pciintel/pci.c	(revision e8d6ce2f88c815fa1db7bc2cfaa982ab53208b5a)
@@ -454,5 +454,8 @@
 {
 	/* Value of the BAR */
-	uint32_t val, mask;
+	uint32_t val;
+	uint32_t bar;
+	uint32_t mask;
+
 	/* IO space address */
 	bool io;
@@ -492,6 +495,14 @@
 	/* Get the address mask. */
 	pci_conf_write_32(fun, addr, 0xffffffff);
-	mask &= pci_conf_read_32(fun, addr);
-	
+	bar = pci_conf_read_32(fun, addr);
+
+	/*
+ 	 * Unimplemented BARs read back as all 0's.
+ 	 */
+	if (!bar)
+		return addr + (addrw64 ? 8 : 4);
+
+	mask &= bar;	
+
 	/* Restore the original value. */
 	pci_conf_write_32(fun, addr, val);