diff --git a/[refs] b/[refs]
index 98475d09148d..cf03c0bb7f25 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4ccf4ae3144360ab9c00d0b53427f43369287bfb
+refs/heads/master: 4ea8a5d8b57cd504b4b2de1212523848e7ab50cf
diff --git a/trunk/arch/x86_64/kernel/pci-calgary.c b/trunk/arch/x86_64/kernel/pci-calgary.c
index cd866135e4ef..466588f95601 100644
--- a/trunk/arch/x86_64/kernel/pci-calgary.c
+++ b/trunk/arch/x86_64/kernel/pci-calgary.c
@@ -86,7 +86,8 @@
 
 #define MAX_NUM_OF_PHBS		8 /* how many PHBs in total? */
 #define MAX_NUM_CHASSIS		8 /* max number of chassis */
-#define MAX_PHB_BUS_NUM		(MAX_NUM_OF_PHBS * MAX_NUM_CHASSIS * 2) /* max dev->bus->number */
+/* MAX_PHB_BUS_NUM is the maximal possible dev->bus->number */
+#define MAX_PHB_BUS_NUM		(MAX_NUM_OF_PHBS * MAX_NUM_CHASSIS * 2)
 #define PHBS_PER_CALGARY	4
 
 /* register offsets in Calgary's internal register space */