1 files changed, 4 insertions, 4 deletions

diff --git a/arch/mips/txx9/rbtx4938/irq.c b/arch/mips/txx9/rbtx4938/irq.c
index ca2f8306ce93..7d21befb8932 100644
--- a/arch/mips/txx9/rbtx4938/irq.c
+++ b/arch/mips/txx9/rbtx4938/irq.c
@@ -85,10 +85,10 @@ static int toshiba_rbtx4938_irq_nested(int sw_irq)
         u8 level3;
 
         level3 = readb(rbtx4938_imstat_addr);
-        if (level3)
-                /* must use fls so onboard ATA has priority */
-                sw_irq = RBTX4938_IRQ_IOC + fls(level3) - 1;
-        return sw_irq;
+        if (unlikely(!level3))
+                return -1;
+        /* must use fls so onboard ATA has priority */
+        return RBTX4938_IRQ_IOC + __fls8(level3);
 }
 
 static void __init