Index: linux-work/drivers/macintosh/smu.c
===================================================================
--- linux-work.orig/drivers/macintosh/smu.c	2005-09-29 16:51:57.000000000 +1000
+++ linux-work/drivers/macintosh/smu.c	2005-09-29 16:52:37.000000000 +1000
@@ -155,8 +155,10 @@
 	spin_lock_irqsave(&smu->lock, flags);
 
 	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
-	if ((gpio & 7) != 7)
+	if ((gpio & 7) != 7) {
+		spin_unlock_irqrestore(&smu->lock, flags);
 		return IRQ_HANDLED;
+	}
 
 	cmd = smu->cmd_cur;
 	smu->cmd_cur = NULL;