1 files changed, 2 insertions, 1 deletions

diff --git a/include/asm-x86_64/mpspec.h b/include/asm-x86_64/mpspec.h
index f267e10c023d..6b375384f5c2 100644
--- a/include/asm-x86_64/mpspec.h
+++ b/include/asm-x86_64/mpspec.h
@@ -157,7 +157,8 @@ struct mpc_config_lintsrc
  */
 
 #define MAX_MP_BUSSES 256
-#define MAX_IRQ_SOURCES 256
+/* Each PCI slot may be a combo card with its own bus.  4 IRQ pins per slot. */
+#define MAX_IRQ_SOURCES (MAX_MP_BUSSES * 4)
 enum mp_bustype {
         MP_BUS_ISA = 1,
         MP_BUS_EISA,