diff -urNp bus-ref/arch/i386/kernel/mpparse.c bus/arch/i386/kernel/mpparse.c
--- bus-ref/arch/i386/kernel/mpparse.c	Thu Aug 29 02:13:02 2002
+++ bus/arch/i386/kernel/mpparse.c	Thu Sep  5 00:43:50 2002
@@ -247,6 +247,11 @@ static void __init MP_bus_info (struct m
 	char str[7];
 	int quad;
 
+	if (m->mpc_busid >= MAX_MP_BUSSES) {
+		printk(KERN_ERR "MAX_MP_BUSSES ERROR mpc_busid %d, max %d\n", m->mpc_busid, MAX_MP_BUSSES);
+		return;
+	}
+
 	memcpy(str, m->mpc_bustype, 6);
 	str[6] = 0;
 	
diff -urNp bus-ref/include/asm-i386/mpspec.h bus/include/asm-i386/mpspec.h
--- bus-ref/include/asm-i386/mpspec.h	Fri Aug  9 14:52:20 2002
+++ bus/include/asm-i386/mpspec.h	Thu Sep  5 00:43:48 2002
@@ -184,13 +184,10 @@ struct mpc_config_translation
  *	7	2 CPU MCA+PCI
  */
 
-#ifdef CONFIG_MULTIQUAD
-#define MAX_IRQ_SOURCES 512
-#else /* !CONFIG_MULTIQUAD */
-#define MAX_IRQ_SOURCES 256
-#endif /* CONFIG_MULTIQUAD */
+#define MAX_MP_BUSSES 257	/* Need max PCI busses for hotplug + 1 for ISA. */
+				/* Four intrs per PCI slot. */
+#define MAX_IRQ_SOURCES (MAX_MP_BUSSES * 4)
 
-#define MAX_MP_BUSSES 32
 enum mp_bustype {
 	MP_BUS_ISA = 1,
 	MP_BUS_EISA,