diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index aaaf0a1..6f1e51d 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -480,19 +480,27 @@
 	int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
 	u32 buses, i, j = 0;
 	u16 bctl;
+	int broken = 0;
 
 	pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
 
 	dev_dbg(&dev->dev, "scanning behind bridge, config %06x, pass %d\n",
 		buses & 0xffffff, pass);
 
+	/* Check if setup is sensible at all */
+	if (!pass &&
+	    ((buses & 0xff) != bus->number || ((buses >> 8) & 0xff) <= bus->number)) {
+		dev_dbg(&dev->dev, "bus configuration invalid, reconfiguring\n");
+		broken = 1;
+	}
+
 	/* Disable MasterAbortMode during probing to avoid reporting
 	   of bus errors (in some architectures) */ 
 	pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl);
 	pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
 			      bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);
 
-	if ((buses & 0xffff00) && !pcibios_assign_all_busses() && !is_cardbus) {
+	if ((buses & 0xffff00) && !pcibios_assign_all_busses() && !is_cardbus && !broken) {
 		unsigned int cmax, busnr;
 		/*
 		 * Bus already configured by firmware, process it in the first
@@ -530,7 +538,7 @@
 		 * do in the second pass.
 		 */
 		if (!pass) {
-			if (pcibios_assign_all_busses())
+			if (pcibios_assign_all_busses() || broken)
 				/* Temporarily disable forwarding of the
 				   configuration cycles on all bridges in
 				   this bus segment to avoid possible