diff --git a/src/devices/pci_device.c b/src/devices/pci_device.c
index 4a9fa1466e..16e8d3f203 100644
--- a/src/devices/pci_device.c
+++ b/src/devices/pci_device.c
@@ -1019,6 +1019,14 @@ unsigned int pci_scan_bus(struct bus *bus,
 	printk(BIOS_DEBUG, "PCI: pci_scan_bus for bus %02x\n", bus->secondary);
 #endif
 
+	// Maximum sane devfn is 0xFF
+	if (max_devfn > 0xff) {
+		printk(BIOS_ERR, "PCI: pci_scan_bus limits devfn %x - devfn %x\n",
+			   min_devfn, max_devfn );
+		printk(BIOS_ERR, "PCI: pci_scan_bus upper limit too big. Using 0xff.\n");
+		max_devfn=0xff;
+	}
+
 	old_devices = bus->children;
 	bus->children = NULL;
 
diff --git a/src/southbridge/amd/sb700/Kconfig b/src/southbridge/amd/sb700/Kconfig
index db43e5e51d..e7592897e1 100644
--- a/src/southbridge/amd/sb700/Kconfig
+++ b/src/southbridge/amd/sb700/Kconfig
@@ -20,3 +20,9 @@
 config SOUTHBRIDGE_AMD_SB700
 	bool
 	select IOAPIC
+
+config SOUTHBRIDGE_AMD_SB700_SKIP_ISA_DMA_INIT
+	bool
+	default n
+	depends on SOUTHBRIDGE_AMD_SB700
+
diff --git a/src/southbridge/amd/sb700/sb700_lpc.c b/src/southbridge/amd/sb700/sb700_lpc.c
index 3a75512260..14ed1b5418 100644
--- a/src/southbridge/amd/sb700/sb700_lpc.c
+++ b/src/southbridge/amd/sb700/sb700_lpc.c
@@ -42,7 +42,11 @@ static void lpc_init(device_t dev)
 	pci_write_config32(sm_dev, 0x64, dword);
 
 	/* Initialize isa dma */
+#if CONFIG_SOUTHBRIDGE_AMD_SB700_SKIP_ISA_DMA_INIT
+	printk(BIOS_DEBUG, "Skipping isa_dma_init() to avoid getting stuck.\n");
+#else
 	isa_dma_init();
+#endif
 
 	/* Enable DMA transaction on the LPC bus */
 	byte = pci_read_config8(dev, 0x40);