diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index c4a560e..34f124d 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -287,6 +287,11 @@
 	tx->flags |= DMA_CTRL_ACK;
 }
 
+static inline void async_tx_clear_ack(struct dma_async_tx_descriptor *tx)
+{
+	tx->flags &= ~DMA_CTRL_ACK;
+}
+
 static inline bool async_tx_test_ack(struct dma_async_tx_descriptor *tx)
 {
 	return (tx->flags & DMA_CTRL_ACK) == DMA_CTRL_ACK;