diff --git a/arch/arm/mach-pxa/viper.c b/arch/arm/mach-pxa/viper.c
index 89f258c..12d4ed3 100644
--- a/arch/arm/mach-pxa/viper.c
+++ b/arch/arm/mach-pxa/viper.c
@@ -281,7 +281,7 @@
 	do {
 		/* we're in a chained irq handler,
 		 * so ack the interrupt by hand */
-		GEDR(VIPER_CPLD_GPIO) = GPIO_bit(VIPER_CPLD_GPIO);
+		desc->chip->ack(irq);
 
 		if (likely(pending)) {
 			irq = viper_bit_to_irq(__ffs(pending));