diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 2673890c7690..c87227bf6e68 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -681,9 +681,10 @@ static void msdc_prepare_data(struct msdc_host *host, struct mmc_request *mrq)
 	struct mmc_data *data = mrq->data;
 
 	if (!(data->host_cookie & MSDC_PREPARE_FLAG)) {
-		data->host_cookie |= MSDC_PREPARE_FLAG;
 		data->sg_count = dma_map_sg(host->dev, data->sg, data->sg_len,
 					    mmc_get_dma_dir(data));
+		if (data->sg_count)
+			data->host_cookie |= MSDC_PREPARE_FLAG;
 	}
 }