diff --git a/arch/arm/mach-ixp2000/pci.c b/arch/arm/mach-ixp2000/pci.c
index 5ff2f27..0788fb2 100644
--- a/arch/arm/mach-ixp2000/pci.c
+++ b/arch/arm/mach-ixp2000/pci.c
@@ -198,6 +198,19 @@
 void __init
 ixp2000_pci_preinit(void)
 {
+#ifndef CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO
+	/*
+	 * Configure the PCI unit to properly byteswap I/O transactions,
+	 * and verify that it worked.
+	 */
+	ixp2000_reg_write(IXP2000_PCI_CONTROL,
+			  (*IXP2000_PCI_CONTROL | PCI_CONTROL_IEE));
+
+	if ((*IXP2000_PCI_CONTROL & PCI_CONTROL_IEE) == 0)
+		panic("IXP2000: PCI I/O is broken on this ixp model, and "
+			"the needed workaround has not been configured in");
+#endif
+
 	hook_fault_code(16+6, ixp2000_pci_abort_handler, SIGBUS,
 				"PCI config cycle to non-existent device");
 }