1 files changed, 1 insertions, 1 deletions

diff --git a/arch/powerpc/sysdev/cpm2_pic.c b/arch/powerpc/sysdev/cpm2_pic.c
index b16ca3ed65d2..78f1f7cca0a0 100644
--- a/arch/powerpc/sysdev/cpm2_pic.c
+++ b/arch/powerpc/sysdev/cpm2_pic.c
@@ -165,7 +165,7 @@ static int cpm2_set_irq_type(unsigned int virq, unsigned int flow_type)
                         edibit = (14 - (src - CPM2_IRQ_EXT1));
         else
                 if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0)
-                        edibit = (31 - (src - CPM2_IRQ_PORTC15));
+                        edibit = (31 - (CPM2_IRQ_PORTC0 - src));
                 else
                         return (flow_type & IRQ_TYPE_LEVEL_LOW) ? 0 : -EINVAL;