diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
index 77c23f5a003750fdecf28f17d4ddab06a2ed3258..72efbe5be5781233c2a98ba636f0f1fb26199fc0 100644
--- a/arch/arm/plat-omap/mailbox.c
+++ b/arch/arm/plat-omap/mailbox.c
@@ -146,7 +146,8 @@ static void mbox_rx_work(struct work_struct *work)
 
 		msg = (mbox_msg_t)rq->special;
 		blk_end_request_all(rq, 0);
-		mbox->rxq->callback((void *)msg);
+		if (mbox->rxq->callback)
+			mbox->rxq->callback((void *)msg);
 	}
 }