Index: linux-2.6.38-rc6/drivers/cbus/retu.c
===================================================================
--- linux-2.6.38-rc6.orig/drivers/cbus/retu.c	2011-02-27 18:01:26.306458689 +0100
+++ linux-2.6.38-rc6/drivers/cbus/retu.c	2011-02-27 18:05:56.472263901 +0100
@@ -205,7 +205,7 @@
 		return IRQ_NONE;
 	}
 
-	for (i = 0; idr != 0; i++, idr >>= 1) {
+	for (i = retu->irq_base; idr != 0; i++, idr >>= 1) {
 		if (!(idr & 1))
 			continue;