diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h
index 7692c86..47e0997 100644
--- a/drivers/dma/dmaengine.h
+++ b/drivers/dma/dmaengine.h

@@ -5,6 +5,7 @@
 #ifndef DMAENGINE_H
 #define DMAENGINE_H
 
+#include <linux/bug.h>
 #include <linux/dmaengine.h>
 
 /**

@@ -27,4 +28,21 @@ static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descriptor *tx)
 	return cookie;
 }
 
+/**
+ * dma_cookie_complete - complete a descriptor
+ * @tx: descriptor to complete
+ *
+ * Mark this descriptor complete by updating the channels completed
+ * cookie marker.  Zero the descriptors cookie to prevent accidental
+ * repeated completions.
+ *
+ * Note: caller is expected to hold a lock to prevent concurrency.
+ */
+static inline void dma_cookie_complete(struct dma_async_tx_descriptor *tx)
+{
+	BUG_ON(tx->cookie < DMA_MIN_COOKIE);
+	tx->chan->completed_cookie = tx->cookie;
+	tx->cookie = 0;
+}
+
 #endif

diff --git a/drivers/dma/ep93xx_dma.c b/drivers/dma/ep93xx_dma.c
index e5aaae8..1c56f75 100644
--- a/drivers/dma/ep93xx_dma.c
+++ b/drivers/dma/ep93xx_dma.c

@@ -703,7 +703,7 @@ static void ep93xx_dma_tasklet(unsigned long data)
 	desc = ep93xx_dma_get_active(edmac);
 	if (desc) {
 		if (desc->complete) {
-			edmac->chan.completed_cookie = desc->txd.cookie;
+			dma_cookie_complete(&desc->txd);
 			list_splice_init(&edmac->active, &list);
 		}
 		callback = desc->txd.callback;