diff --git a/drivers/crypto/rockchip/rk3288_crypto_ahash.c b/drivers/crypto/rockchip/rk3288_crypto_ahash.c
index 29c9537216fa..8f3406289df4 100644
--- a/drivers/crypto/rockchip/rk3288_crypto_ahash.c
+++ b/drivers/crypto/rockchip/rk3288_crypto_ahash.c
@@ -252,7 +252,7 @@ static void rk_hash_unprepare(struct crypto_engine *engine, void *breq)
 	struct rk_ahash_rctx *rctx = ahash_request_ctx(areq);
 	struct rk_crypto_info *rkc = rctx->dev;
 
-	dma_unmap_sg(rkc->dev, areq->src, rctx->nrsg, DMA_TO_DEVICE);
+	dma_unmap_sg(rkc->dev, areq->src, sg_nents(areq->src), DMA_TO_DEVICE);
 }
 
 static int rk_hash_run(struct crypto_engine *engine, void *breq)